Seal Beach City Council
November 10, 2025

SUBMITTED BY: NOTED AND APPROVED:

Shaun Temple Patrick Gallegos
Shaun Temple, Interim
Community Development
Director
Patrick Gallegos, City Manager
Prepared by: Megan Bolton, Management Analyst
ATTACHMENTS:

A. Ordinance 1724
B. Resolution 7712
C. SBMC Chapter 4.60 (Parks and Recreation Facilities Improvement Fee) (Exhibit “A” of Ordinance 1724)
D. Seal Beach Parks Impact Fee Update Nexus Study (Exhibit “A” of Resolution 7712)
1 ORDINANCE 1724

AN ORDINANCE OF THE CITY OF SEAL BEACH ADDING
CHAPTER 4.60 (PARKS AND RECREATION FACILITIES

IMPACT FEE) TO THE SEAL BEACH MUNICIPAL CODE

TO AUTHORIZE COLLECTION OF DEVELOPMENT

IMPACT FEES FOR PARKS AND RECREATION
FACILITIES AND REPEALING SECTION 10.50.010 (PARK

DEDICATIONS AND FEES) OF THE SEAL BEACH

MUNICIPAL CODE
WHEREAS, Section 200 of the City of Seal Beach (“City”) Charter vests the City Council with the authority to make and enforce all laws and regulations in respect to municipal affairs, subject only to such restrictions and limitations as may be provided in the Charter and in the Constitution of the State of California, and the power to exercise any and all rights, powers and privileges heretofore or hereafter established, granted or prescribed by any law of the State, by the Charter, or by other lawful authority, or which a municipal corporation might or could exercise under the Constitution of the State of California; and, WHEREAS, cities may apply fees for proposed developments to cover the cost of public facilities by way of its police power as codified in the California Constitution Article XI Section 7; and,
WHEREAS, California Government Code Section 66000 et seq. ("Mitigation Fee Act") authorizes the City to collect fees in connection with approval of a development project for the purpose of defraying all or a portion of the cost of public facilities reasonably intended to mitigate impacts caused by the development project; and, WHEREAS, development impact fees must be supported by a nexus study which calculates the purpose of the fee, the use to which it will be put, the relationship and rough proportionality between the fee and the development, and establish the need for the fee pursuant to the Mitigation Fee Act and constitutional principles; and, WHEREAS, the Community Development Department commissioned a development impact fee nexus study with Economic & Planning Systems, Inc.; and, WHEREAS, the City’s 6th Cycle Housing Element projects an increase in the population and residential dwelling units in Seal Beach; and,
WHEREAS, the future residential growth will create additional demand on the City’s infrastructure for park and recreation facilities; and, WHEREAS, this Ordinance would add Chapter 4.60 (Parks and Recreation Facilities Impact Fee) in order to authorize the City to collect development impact fees for parks and recreation facilities to cover the cost of parks and recreation facilities needed to serve the needs created by new residential development; and,
2 WHEREAS, Section 10.50.010 (Park Land Dedications and Fees) of the Seal Beach Municipal Code, which is the City’s existing parks fee based on the Quimby Act, is no longer necessary or applicable with the adoption of the Parks and Recreation Facilities Development Impact Fee (Chapter 4.60 Parks and Recreation Facilities Impact Fee); and, WHEREAS, it is the desire of the City Council to repeal Section 10.50.010 (Park Land Dedications and Fees), to remove it from the Seal Beach Municipal Code; and, WHEREAS, a duly noticed public hearing was held by the City Council on November 10, 2025 in the Council Chambers at 211 Eighth Street, Seal Beach, California. A notice of time, place and purpose of the public hearing was given in accordance with the Mitigation Fee Act. Evidence, both written and oral, was presented to, and considered by, the City Council at this public hearing; and,
WHEREAS, the City Council finds that the record of these proceedings, including the nexus study, the City’s General Plan, ordinances and resolutions, the staff report, written correspondence received by the City, and the testimony received at the hearing prior to the adoption of this Ordinance contain substantial evidence to support the imposition and collection of the development impact fee established herein; and, WHEREAS, the City Council has reviewed and considered the parks and recreation facilities impact fee established herein and finds that the fee will mitigate some of the impacts associated with additional capital and infrastructure needs necessitated by new residential development in the City.

NOW THEREFORE, THE CITY COUNCIL OF THE CITY OF SEAL BEACH DOES ORDAIN AS FOLLOWS:

Section 1: Chapter 4.60 (Parks and Recreation Facilities Impact Fee) is hereby added to the Seal Beach Municipal Code as set forth in Exhibit “A” which is attached hereto and incorporated by reference as though set forth in full.

Section 2: Section 10.50.010 (Park Land Dedications and Fees) is hereby repealed and removed from the Seal Beach Municipal Code in its entirety and is of no further force or effect, except that any fees due and owing as of the effective date of this Ordinance shall be collected.

Section 3: The recitals provided in this Ordinance are true and correct and are incorporated into the substantive portion of this Ordinance.

Section 4: The City Council finds the introduction and adoption of this Ordinance is not subject to the California Environmental Quality Act (Public Resources Code, §§ 21000 et seq., “CEQA”), pursuant to Sections 15060(c)(2) (the activity will not result in a direct or reasonably foreseeable indirect physical change in the environment) 3 and 15060(c)(3) (the activity is not a project as defined in Section 15378) of the CEQA Guidelines, California Code of Regulations, Title 14, Division 6, Chapter 3, because it has no potential for resulting in physical change to the environment, directly or indirectly.

Section 5: Severability. If any section, subsection, subdivision, sentence, clause, phrase, word, or portion of this Ordinance is, for any reason, held to be invalid or unconstitutional by the decision of any court of competent jurisdiction, such decision shall not affect the validity of the remaining portions of this Ordinance. The City Council hereby declares that it would have adopted this Ordinance and each section, subsection, subdivision, sentence, clause, phrase, word, or portion thereof, irrespective of the fact that any one or more sections, subsections, subdivisions, sentences, clauses, phrases, words or portions thereof be declared invalid or unconstitutional.

Section 6: Certification. The City Clerk shall certify the passage and adoption of this Ordinance and shall cause the same to be published or posted in the manner required by law.

Section 7: Effective Date. This Ordinance shall take effect thirty (30) days after its adoption.

INTRODUCED at a regular meeting of the City Council of the City of Seal Beach held on the 10th day of November 2025.

PASSED, APPROVED, AND ADOPTED by the City Council of the City of Seal Beach this ___ day of ________, 2025.

Lisa Landau, Mayor
ATTEST:

Gloria D. Harper, City Clerk
APPROVED AS TO FORM:
__________________________________
Nicholas Ghirelli, City Attorney
4 STATE OF CALIFORNIA }
COUNTY OF ORANGE } SS
CITY OF SEAL BEACH }
I, Gloria D. Harper, City Clerk of the City of Seal Beach, do hereby certify that the foregoing Ordinance 1724 was introduced for first reading at a regular meeting held on the 10th day of November 2025, and was passed, approved, and adopted by the City Council at a regular meeting held on the _____ day of ________ 2025, and do hereby further certify that the Ordinance has been published pursuant to the Seal Beach Charter and Resolution Number 2836.

Gloria D. Harper, City Clerk
Attachments:

Exhibit “A”: SBMC Chapter 4.60 (Parks and Recreation Facilities Impact Fee) RESOLUTION 7712

A RESOLUTION OF THE SEAL BEACH CITY COUNCIL APPROVING

A DEVELOPMENT IMPACT FEE NEXUS STUDY FOR THE PARKS

AND RECREATION FACILITIES FEE, ADOPTING THE PARKS AND

RECREATION FACILITIES FEE CAPITAL IMPROVEMENT PLAN AS

PART OF THE NEXUS STUDY, ESTABLISHING THE FEE AMOUNTS

FOR THE PARKS AND RECREATION FACILITIES DEVELOPMENT

IMPACT FEE, AND MAKING A FINDING OF EXEMPTION UNDER
CEQA
WHEREAS, the Mitigation Fee Act, contained in Government Code 66000 et seq., permits the City to impose development impact fees on new development for the purposes of funding public facilities necessary to serve that new development; and, WHEREAS, the City of Seal Beach conducted a comprehensive Nexus Study prepared by Economic Planning Systems, Inc. (EPS), included as Exhibit “A” to this Resolution (“EPS Nexus Study”), to support the adoption of a Citywide Parks and Recreation Facilities Impact Fee Program (DIF Program) and Park and Recreation Facilities Fee Capital Improvement Plan, included as a part of the EPS Nexus Study, to fund Parks and Recreation capital facilities needed to accommodate new development; and, WHEREAS, development impact fees are monetary exactions, other than taxes or special assessments, charged to applicants in connection with approval of a development project, with the purpose to defray all or part of the cost of public facilities related to new development; and,
WHEREAS, the City Council desires to establish an impact fee on new development to fund the cost of park and recreational facilities within the City; and, WHEREAS, proposed Ordinance 1724, once effective, will add Chapter 4.60 (“Parks and Recreation Facilities Impact Fee”) to the Municipal Code to establish a Parks and Recreation Facilities Impact Fee; and,
WHEREAS, the proposed Municipal Code provisions will establish the program and the requirements for imposition of a development impact fee on development projects, as supported by the EPS Nexus Study, and provide that the City Council shall, by resolution, impose the specific amount of the development impact fee that will be levied on new residential development in the City; and,
WHEREAS, the EPS Nexus Study identifies the purpose of the fee and the use of the fee, and demonstrates a reasonable relationship between the fee’s use, the type of development projects where the fee will be imposed, provides how there is a reasonable relationship between the amount of the fee, and the cost of the public facility or portion of the public facility attributable to the development. In addition, the EPS Nexus Study identifies capital projects necessary to meet the goals, programs and objectives within the City’s General Plan; and,
WHEREAS, the EPS Nexus Study provides the documentation, detail, and other information required by the Mitigation Fee Act as the basis for the adoption and imposition of the development impact fee. Furthermore, the Nexus Study describes the benefit and impact area on which the development impact fee is to be imposed, lists specific public improvements to be financed through the imposition and collection of the development impact fee, describes the estimated cost of providing the improvements and facilities, describes the reasonable relationship between the development impact fee and the various types of new development, and otherwise satisfies the requirements of the law with regard to the imposition and collection of development impact fees; and, WHEREAS, the fee calculations exclude maintenance costs and land acquisition, and are allocated proportionally to net new residential development only, which aligns with state requirements and current city development patterns; and, WHEREAS, the City currently utilizes a Quimby Act fee for new residential subdivisions, which does not adequately address service needs for multifamily and infill development, nor existing service standards; and,
WHEREAS, the updated DIF Program replaces the Quimby fee with a structure that allocates costs and ensures compliance with the required nexus and reporting standards; and,
WHEREAS, AB 602 requires adoption of a Parks and Recreation Facilities Impact Fee Capital Improvement Plan outlining improvements needed to serve new residents; and, WHEREAS, the collection of development impact fees is projected to generate funding for Parks and Recreation facilities at build-out, supporting the City’s ability to maintain adopted service standards.

WHEREAS, the City has complied with the notice and hearing requirements of state law and the Mitigation Fee Act prior to adopting the Nexus Study, Capital Improvement Plan, and the fee specified in this Resolution, and a notice of public hearing on the development impact fee was mailed as required by law to any interested party who filed a written request with the City Clerk for mailed notice of a meeting on new or increased fees; and, WHEREAS, a duly noticed public hearing was held by the City Council on November 10, 2025 in the Council Chambers at 211 Eighth Street, Seal Beach, California. A notice of time, place and purpose of the public hearing was given in accordance with the Mitigation Fee Act. Evidence, both written and oral, was presented to, and considered by, the City Council at this public hearing.

WHEREAS, the City Council has reviewed and considered the development impact fee established herein, and finds that the fee will mitigate some of the impacts associated with additional capital and infrastructure needs necessitated by new residential development in the City.

NOW, THEREFORE, the Seal Beach City Council does resolve, declare, determine, and order as follows:

Section 1. The City Council hereby specifically finds that all of the facts and recitals set forth above are true and correct and incorporated as a material part of this Resolution.

Section 2. The City Council hereby approves the EPS Nexus Fee Study, and the findings contained therein. The EPS Nexus Study shall constitute the current “Study” for the Parks and Recreation Facilities Impact Fee pursuant to the proposed Chapter 4.60 of the Seal Beach Municipal Code. A copy of the EPS Nexus Study shall be on file with the City Clerk and available during regular City business hours for public inspection. The EPS Nexus Study explains (1) the purpose of the impact fee; (2) the use of the impact fee; (3) the reasonable relationship between the use of the impact fee and the development type on which it is imposed; (4) the reasonable relationship between the need for the facilities and the type of development between the need for the type of development on which the fee is imposed; and (5) the reasonable relationship between the amount of the fee and facility cost attributable to the applicable development project. The City Council agrees with the findings set forth in the EPS Nexus Study and adopts them as their own as if set forth in full here.

Section 3. The City Council hereby adopts the Parks and Recreational Facilities Fee Capital Improvement Plan as detailed in Appendix Table A-6 of the EPS Nexus Study, attached hereto as Exhibit “A” and incorporated herein by reference.

Section 4. The Council hereby establishes the Parks and Recreation Facilities Development Impact Fee and the rates of the fee for new residential park and recreation development impact fees as set forth in Chapter 4 of the EPS Nexus Study, attached hereto as Exhibit “A” and incorporated herein by reference, for single-family and multifamily units, including exemptions and proportional charges for ADUs, and the minimum/maximum schedule. The Seal Beach Fee Schedule shall be amended to contain the fees and amounts identified therein.

Section 5. The City Council adopts the methodology set forth in the EPS Nexus Study for calculating and collecting the development impact fee adopted herein.

The amount of the development impact fee shall be adjusted annually in July of each calendar year beginning in 2026, using the California Construction Cost Index (CCI) for the twelve-month period ending in May, or a similar published index if the CCI is no longer available. The City Council hereby authorizes the City Manager, or designee, to make such annual adjustments to certain fees based on an inflationary factors effective July 1 of each year.

Section 6. The Parks and Recreation Facilities Impact Fee shall be paid when required by the applicable provisions of the Seal Beach Municipal Code and in accordance with Government Code section 66007.

Section 7. The Parks and Recreation Facilities Impact Fee shall be effective on the later of: (i) the sixtieth (60th) day following the adoption of this Resolution and (ii) the effective date of proposed Ordinance 1724, an ordinance adding Chapter 4.60 (“Parks and Recreation Facilities Impact Fee”) to the Municipal Code.

Section 8. The City shall include an Administration Fee in the not to exceed amount of two percent (2%) of the total project cost for the management of the development impact fee program.

Section 9. Nothing in this Resolution shall repeal, amend or supersede any other City imposed fees except for the development impact fee addressed in the EPS Nexus Studies and expressly established by this Resolution.

Section 10. If any section, subsection, sentence, clause, phrase or portion of this Resolution is for any reason held to be invalid or unenforceable by a court of competent jurisdiction, the remaining portions of this Resolution shall nonetheless remain in full force and effect. The City Council hereby declares that it would have adopted each section, subsection, sentence, clause, phrase or portion of this Resolution, irrespective of the fact that any one or more sections, subsections, sentences, clauses, phrases or portions of this Resolution be declared invalid or unenforceable.

PASSED, APPROVED AND ADOPTED by the Seal Beach City Council at a regular meeting held on the 10th day of November 2025 by the following vote:

AYES: Council Members
NOES: Council Members
ABSENT: Council Members
ABSTAIN: Council Members

Lisa Landau, Mayor
ATTEST:

Gloria D. Harper, City Clerk
STATE OF CALIFORNIA }
COUNTY OF ORANGE } SS
CITY OF SEAL BEACH }
I, Gloria D. Harper, City Clerk of the City of Seal Beach, do hereby certify that the foregoing resolution is the original copy of Resolution 7712 on file in the office of the City Clerk, passed, approved, and adopted by the City Council at a regular meeting held on the 10th day of November 2025.

Gloria D. Harper, City Clerk
Attachments:

Exhibit “A”: Seal Beach Parks and Recreation Facilities Impact Fee Nexus Study, Inclusive of Capital Improvement Plan
Exhibit “A”
CHAPTER 4.60

PARKS AND RECREATION FACILITIES IMPACT FEE
§ 4.60.005. Purpose.

To implement the goals and objectives of the capital improvement program for parks and recreation facilities and equipment of the City of Seal Beach, and to mitigate the impacts to the City's park and recreational facilities caused by new development in the City, certain public facilities and equipment must be constructed and/or acquired. The public facilities and equipment are specifically identified in the City's capital improvement program for facilities and equipment as adopted by the City Council and as amended from time to time. The list of recreational facilities and equipment may be added to or deleted from the approved program.

The City Council has determined that a development impact fee is needed to finance these public improvements and to pay for new development's fair share of the costs of these improvements.
§ 4.60.010. Definitions.

For the purposes of this chapter, the following words and phrases shall mean:
“Multifamily housing or dwellings” is a building used and/or designed as residences containing two or more residential dwelling units including mixed-use developments that combine residential dwellings with nonresidential uses in the same building or development site. “Public Facilities” means those park and recreation facilities, land, buildings, improvements, or infrastructure and similar facilities utilized for park and recreational purposes including vehicles and equipment.
“Residential development” includes all residential dwelling units constructed for the first time or when existing structures are remodeled and added to or otherwise altered to increase the number of dwelling units. A mixed-use development containing dwelling units is considered a residential development.
“Residential dwelling unit” is a room or group of internally connected rooms that have sleeping, cooking, eating, and sanitation facilities, but not more than one kitchen, which constitute an independent housekeeping unit, occupied by or intended for one household. “Single-Family Dwelling unit” is a building or portion of a building used and/or designed as residence for one family.
§ 4.60.015. Establishment and administration of park and recreation facilities impact fees.

A. A parks and recreation facilities impact fee is established on issuance of all building permits, for residential development within the City to pay for the City’s buildings, furnishings, vehicles, equipment and similar facilities utilized for park and recreational purposes as shown in the adopted capital improvement program for facilities and equipment.

B. The City Council shall, in a council resolution, set forth the specific amount of the fee, describe the benefit and impact area on which the development impact fee is imposed, list the specific public improvements to be financed, describe the estimate cost of these facilities, describe the reasonable relationship between this fee and the various types of new residential developments and set forth time for payment. The City Council shall review this fee as required by law to determine whether the fee amounts are reasonably related to the impacts of developments and whether the described facilities are still needed.

C. The finance director shall establish a park and recreation facilities impact fee fund. All fees collected pursuant to this chapter shall be deposited in this fund and shall be expended towards expanding the City’s parks and recreation facility capacity to mitigate the impacts of new residential development in the City.

D. A fee is imposed in the amounts set forth in this chapter and shall be applicable to every dwelling unit as defined in section 4.60.010 constructed in the City after the effective date of the ordinance codified in this chapter and shall be known as the park and recreation facilities impact fee.
§ 4.60.020. Payment.

The fee imposed by this chapter shall be due and payable no sooner than issuance of building permits and no later than issuance of a certificate of occupancy for the dwelling unit(s) subject to the fee in accordance with applicable law. No certificate of occupancy or temporary certificate of occupancy may be issued until the development fee has been paid in full. The amount of the fee shall be calculated at the time the fee is paid, based upon the rate then in effect.
§ 4.60.025. Fees.

The fees imposed by this chapter shall be set by resolution of the City Council. § 4.60.030. Fee exemptions.

In the event that a development project is found to have no impact on facilities for which impact fees are charged, such project must be exempted from the fees. § 4.60.035. Use of fees.

The city council finds that there is established a park fund where all sums collected pursuant to this chapter shall be deposited and shall be used to expand the City’s parks and recreation facilities to mitigate the impacts of new residential development in the City as set forth in the Seal Beach Parks Impact Fee Update Nexus Study. Those public facilities and other assets are identified in the capital improvement plan adopted as part of such study.

SEAL BEACH PARKS

IMPACT FEE UPDATE

NEXUS STUDY

DRAFT REPORT
Prepared for: Prepared by:

City of Seal Beach Economic & Planning Systems, Inc.

August 14, 2025
EPS #244007
Table of Contents

1. Introduction and Results 1
Introduction.............................................................................................................................................................. 1 Legal Context........................................................................................................................................................... 1 Summary of Proposed Development Impact Fees........................................................................................... 3 Methodology and Key Assumptions ................................................................................................................... 5 Capital Improvement Program ............................................................................................................................. 6

2. Development and Demographic Assumptions 7
Future Development Forecasts ........................................................................................................................... 7 Unit and Household Size Estimates .................................................................................................................... 8

3. Park Facility Improvements and Costs 9
Existing Service Level Assumptions .................................................................................................................... 9 Facility Needs Attributable to Growth .............................................................................................................10 New Park Facility Cost Estimates......................................................................................................................10

4. Nexus Findings and Fee Calculation 12
Park and Recreation Fee Calculation................................................................................................................12 Nexus Findings ......................................................................................................................................................16 List of Tables
Table 1 Maximum Allowable Park and Recreation Development Impact Fee.......................................................3 Table 2 Summary of Parks and Recreation DIF Capital Improvement Plan...........................................................6 Table 3 Seal Beach Housing Element Growth Forecast.............................................................................................7 Table 4 Seal Beach Unit Size and Household Size Estimates....................................................................................8 Table 5 Existing Park Facilities Service Level ...............................................................................................................9 Table 6 Park and Recreation Facility Needs Attributable to Growth....................................................................10 Table 7 Parks Facility Capital Costs for New Development....................................................................................11 Table 8 Calculation of Parks Impact Fee Per Square Foot.......................................................................................13 Table 9 Residential Maximum and Minimum Per Square Foot Conversion.........................................................16 Economic & Planning Systems, Inc. 1 Introduction and Results

1. Introduction and Results
Introduction
This Development Impact Fee Nexus Study (Nexus Study or Report) provides the City of Seal Beach (City) with the necessary technical documentation to support the adoption of a Citywide Development Impact Fee Program (DIF) to fund parks and recreation capital facilities needed to accommodate growth. The Fee Program described in this Nexus Study has been prepared by Economic & Planning Systems, Inc. (EPS) in consultation with City staff and with reference to the City’s 2013 Parks and Community Services Master Plan.

Impact fees are one-time charges on new development collected and used by jurisdictions to cover the cost of capital facilities and infrastructure needed to serve the needs created by new development. The fees are typically collected upon issuance of a building permit or certificate of occupancy, subject to certain limitations in AB 1600. Based on direction from the City, the Parks and Recreation Fee was calculated to apply to net new residential development only.

In addition, this Fee Program is designed to replace the City’s existing Quimby Act fees, outlined under Title 10.50.010 of the Seal Beach Municipal Code, as described further below.

The Fee Program described in this Nexus Study is designed to be consistent with the most recent relevant case law relating to impact fees, including Scheetz v.

County of El Dorado, and Government Code Section 66000 et seq. (subsequently referred to as AB 1600) as recently amended. The Report provides the nexus findings and associated fee calculations for the maximum parks facilities fees the City can charge pursuant to Nolan/Dollan and AB 1600, as amended by AB 602.

Legal Context
Impact fee revenues are used to cover the cost of constructing capital and infrastructure improvements required to serve new development and growth in the area in which they apply. AB 1600 requires that the development impact fees must be based on a reasonable nexus, or connection, between new development and the need for specific capital facilities and improvements. Impact fee revenue cannot be used to cover operation and maintenance costs of these or any other facilities and infrastructure. In addition, impact fee revenue cannot be collected or used to cover the cost of preexisting infrastructure needs or deficiencies.

In establishing, increasing, or imposing a fee as a condition for approval of a development project, Government Code sections 66001(a) and (b) require a local agency to:

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 2 Introduction and Results

1. Identify the purpose of the fee;

2. Identify how the fee is to be used, including identification of public facilities to be financed;

3. Determine how a reasonable relationship exists between the fee use and the type of development project on which the fee is being imposed;

4. Determine how there is a reasonable relationship between the need for the public facility and the type of development project on which the fee is imposed; and

5. Show there is a reasonable relationship between the amount of the fee and the cost of the public facility.

The nexus findings for this fee study are provided in Chapter 4 of this Report as is the full development impact fee calculation.

In September 2021, the State of California adopted Assembly Bill (AB) 602, which included new Government Code section 66016.5 and created several new requirements related to development and implementation of impact fee programs. The key provisions related to the calculations documented in this Nexus Report are summarized below.
• Capital Improvement Plan: AB 602 requires that jurisdictions adopt a capital improvement plan (CIP) as part of the nexus report process. This adoption can occur just prior to the fee ordinance adoption through a resolution.

Accordingly, this Nexus Study relies on a Seal Beach Parks and Recreation DIF Capital Improvement Plan (Parks DIF CIP) to be approved by the City Council in conjunction with the DIF Program. The Parks DIF CIP has been developed as part of this Nexus Study and is presented herein (see Table 2 for a summary CIP table and Appendix Table A-6 for the full CIP).
• Explanation of Level of Service: AB 602 requires the nexus report indicate whether the fee calculation is based on existing levels of service or on different levels of service, and to provide an explanation in the latter case. This Nexus Study relies on service standards developed in consultation with City staff based on the existing relationship between park facilities and the residential population in the City. The level of service is articulated in Chapter 4 (see Table 4).
• Residential Fee to be Charged in Proportion to Unit Size: AB 602 notes that for fees adopted after July 1, 2022, the nexus study must “either calculate a fee levied or imposed on a housing development proportionately to the square footage of the proposed units, or make specific findings explaining why square footage is not an appropriate metric to calculate the fees.” AB 602 also notes

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 3 Introduction and Results that “This bill would require that a local agency that calculates fees proportionately to the square footage of the proposed units be deemed to have used a valid method to establish a reasonable relationship between the fee charged and the burden posed by the development.”
This analysis relies on assumptions about the average unit size for newly developed residential units based on market research and conversations with City Staff. The average home sizes were then applied to the per unit fees, to determine the average per square foot fee for both single-family and multifamily development. The nexus analysis assumes that on average larger housing units will accommodate more people than smaller housing units but includes a maximum and minimum fee to reflect the fact that differences will likely be less pronounced at either end of the spectrum.

Summary of Proposed Development Impact Fees
Maximum Allowable Nexus Based Fees
Table 1 summarizes the single- and multifamily development impact fee levels calculated in this Nexus Report. As shown, based on the nexus analysis provided herein, the maximum allowable park and recreation fee is $3.83 per square foot for single-family and $5.40 per square foot for multifamily, respectively. The per square foot amount incorporates data on the average unit sizes for new housing development in the region and average household size for single and multifamily units, respectively. The per square fee rate equates to an average fee of about $6,736 for single-family units and $4,647 for multifamily units. The fee calculations include a two percent administration charge to cover the cost of implementation, as described in Chapter 4.

Table 1 Maximum Allowable Park and Recreation Development Impact Fee Single-Family3 $3.83 $6,736 $18,711 $3,119
Multifamily3 $5.40 $4,647 $15,593 $3,119
Fee Amount per Housing Unit
Average
Fee1
Maximum
Fee2
Minimum
Fee2
Residential Unit
Type
Fee Amount Per
Square Foot
Source: City of Seal Beach; Economic & Planning Systems, Inc. [1] Based on average unit sizes for new development in the past five years in the broader region for single-family and multifamily units, respectively and associated average household size. [2] Based on likely maximum or minimum people per household by residential unit type. [3] Fee amount includes a two percent (2%) program administration charge.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 4 Introduction and Results EPS recommends that the City adopt differentiated fees per square foot for single-family and multifamily residential units consistent with AB 602 and to reflect the varying impacts of each housing type. As documented in this Report, multifamily units tend to house more residents per square foot than single-family units, resulting in different levels of demand for park facilities. Additionally, the City's Housing Element anticipates that future development will primarily take the form of infill multifamily housing. Accordingly, the proposed fee structure aligns with the City’s expected development pattern and better captures the impacts of future growth.

EPS also recommends that the City’s fee program include a maximum and minimum per unit fee to better reflect the true relative impacts of various housing sizes (i.e., square feet of the structure) on park and recreation needs. As shown in Table 1, the maximum and minimum fee per single-family unit is $18,711 and $3,119, respectively. For multifamily units, the maximum and minimum fee per unit is $15,593 and $3,119.

The nexus analysis ties the maximum and minimum fee to the likely largest and smallest household sizes that are likely to occupy single and multi-family structures, respectively, since park usage is ultimately driven by people, not square footage. For example, very large households (e.g., more than six people for single family and five people for multifamily) are relatively uncommon, and additional square footage beyond these thresholds does not necessarily correspond to greater park demand. Likewise, since even the smallest housing structures will have at least one resident, the minimum fee is based on the proportional impact of a one-person household.

The City has the discretion to set the updated fee level at any amount below the maximum justifiable level, as may be informed by relevant policy considerations, and provided that the City must find other sources of revenue to pay for the improvements in the CIP. The updated parks impact fee will apply Citywide and to residential development only, which is a common practice in cities for park fees throughout the state. Consistent with the new requirements of AB 602 (described further above), the updated park and recreation fee will be levied on a per square foot basis. In addition, consistent with Assembly Bill 68 (Government Code 65852.2), the fee will not be applied to Accessory Dwelling Units (ADUs) of less than 750 square feet and will be proportional to the primary unit for ADUs larger than 750 square feet.

Existing Quimby Act Park Fee
The City’s existing parks fee is based on the Quimby Act (Government Code §66477), which authorizes local governments to require new residential subdivisions to dedicate parkland or pay fees to support the provision of parks.

This authority is implemented through Title 10.50.010 of the Seal Beach Municipal Code. The fee is set to $10,000 per single-family dwelling unit and

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 5 Introduction and Results $5,000 for other residential users (each residential unit that is not a single-family dwelling).

As described in this Report, the proposed nexus-based park development impact fee is based on new park and recreation facilities but excludes land acquisition costs. If this revised fee structure is approved, the City will no longer use the existing Quimby Act fee as a source for funding park land acquisition or requiring land dedication. Given the lack of available land that could be used for parks, the high cost of land acquisition, and the City’s limited ability to fund maintenance of additional park land, the focus of the proposed fee is to improve existing recreational and open space facilities. In addition, unlike the existing Quimby Act fee, the proposed development impact fee is not limited to residential subdivisions and can also be charged to multi-family apartments (expected to be a large proportion of future development given built-out nature of City).

Accordingly, the City will repeal the existing requirements detailed in Title

10.50.010 as part of the approval of the new fees calculated in this Report.

Methodology and Key Assumptions
The results of this analysis are based on a variety of conditions and assumptions regarding facility costs, service standards, growth projections, and facility demand. Assumptions are covered in detail in later chapters, though some of the key issues are summarized below:
• Future Development. The fee calculations were based on residential development projections. These are based on the housing growth projections from the City's General Plan Housing Element, adopted on February 7, 2022. • Park and Recreation Improvement Program. The list of parks and recreation improvements included in the Fee Program focus on park buildings, capital improvements, vehicles, and equipment. Most of the improvements are based on service standards derived from City’s 2013 Parks and Community Services Master Plan.
• Cost Estimates. EPS has developed or verified cost estimates for all the parks and recreation improvement projects identified herein. The cost estimates were based on assumptions about the construction of park structures, buildings, equipment or facilities. Assumptions were based on similar parks and recreation spaces and facilities from recent EPS parks and recreation nexus studies and have been reviewed and confirmed by City staff. • Cost Allocation. Based on direction from the City, the Parks and Recreation Fee has been calculated to apply to net new residential development only.

Secondly, only parks and recreation improvement costs specifically required to support new development are included in the development impact fee calculation. Maintenance costs associated with parkland and facilities are excluded from the fee calculation.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 6 Introduction and Results Capital Improvement Program
Development impact fees are derived from a list of specific capital improvement projects and associated costs that are needed in part or in full to accommodate new growth. Consequently, the capital improvements included in the fee program need to be described in sufficient detail to generate cost estimates.

The costs of capital improvements included in the DIF are based on input from City staff and per unit cost factors from similar park nexus studies by EPS. The fee only includes the portion of costs needed to serve new residents and does not fund existing deficiencies. Table 2 summarizes the estimated cost of the DIF Program capital improvements. As shown, the estimated infrastructure hard and soft costs amount to a total of $7.1 million. For the complete Parks CIP, see Appendix Table A-6.

Table 2 Summary of Parks and Recreation DIF Capital Improvement Plan Parks Facilities1 Cost Attributable to
Growth
Community Buildings 1,413 square feet $671,307
Other Developed Parkland 6.2 acres $296,585
Fields 1.6 acres $1,480,945
Hard Courts 0.4 acres $900,162
Indoor Courts 369.4 square feet $849,561
Soft Courts 0.1 acres $134,261
Other Building 1,310 square feet $622,322
Restrooms 367 square feet $698,160
Paved Parking 72.6 spaces $726,374
Gravel Parking 12.5 spaces $62,263
Pool 175.7 square feet $702,699
Total $7,144,640
[1] See Appendix Table A-6 for the full Parks CIP.

Space Attributable to
Growth
Source: City of Seal Beach; Economic & Planning Systems, Inc.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 7 Development and Demographic Assumptions

2. Development and Demographic
Assumptions
Estimates of the nexus-supported citywide parks and recreation fees are, in part, driven by forecasts of new growth in the City of Seal Beach. Accordingly, this chapter documents the growth forecasts and development assumptions that underpin the DIF calculations.

Future Development Forecasts
The DIF is largely predicated on calculations that translate existing and projected housing development into estimates of existing and future park and recreation service levels. The existing and future park service requirements used in the fee program are based on the housing growth projections on the City's General Plan Housing Element, adopted on February 7, 2022. The City’s existing housing inventory is based on the California Department of Finance (DOF) 2021 housing estimates.

As shown in Table 3, the housing inventory is expected to grow by 1,243 units, representing a 9 percent increase from the City’s existing inventory. This estimate would suggest that park and recreation facilities will need to increase by an equivalent percentage in order to maintain existing service levels.

Table 3 Seal Beach Housing Element Growth Forecast
Housing Type Number of Units
Housing Units
Existing Inventory1 14,512
RHNA Allocations2 1,243
Anticipated Housing Inventory 15,755
Percent Change 9%
[1] Existing housing inventory based on 2021 housing unit estimates from the California DOF.
[2] Buildout housing inventory based on the City of Seal Beach 6th Cycle Housing Element 2021 - 2029.

Source: City of Seal Beach; Economic & Planning Systems, Inc.

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Economic & Planning Systems, Inc. 8 Development and Demographic Assumptions Unit and Household Size Estimates
The existing Parks Impact Fee is only charged on new residential developments.

The City, like many other California jurisdictions, intends to continue this approach for the updated fee. Accordingly, the City’s park facility service standards (described further below) will be set on a per residential unit basis.

Consequently, household size by type of unit is a key determinant of the level of new park facilities needed to serve new residential development given the number of people in each unit affects how additional park infrastructure is necessary to maintain the City’s service standards.

To determine average household and unit size, EPS has relied on data from the U.S. Census and various real estate data sources covering the broader area in the past five years. Specifically, single-family unit size is sourced from Redfin and multifamily units are sourced from Costar Group. Single-family homes in the broader area average 2,645 square feet while multifamily units average 861 square feet.

EPS utilized data from the U.S. Census Bureau, 2018-2022 American Community Survey to calculate the average household size between single-family and multifamily units. These average unit and household size estimates used to convert the fee to a per unit and per square foot basis are shown in Table 4.

Table 4 Seal Beach Unit Size and Household Size Estimates Housing Type Average Unit Size
(Square Feet) 1
Average People per
Household2
Housing Unit - 1.88
Single-Family 1,757 2.16
Multifamily 861 1.49
[2] Average household calculations using American Community Survey five-year estimates for the City of Seal Beach.
[1] Average unit size for multifamily homes is based on housing unit constructed in the past five years from Cypress, Huntington Beach, Los Alamitos, Seal Beach, Stanton, and Westminster.

Single family data is sourced Redfin and multifamily data from CoStar Group.

Source: ACS 5-Year Estimates; Redfin; Costar Group; Economic & Planning Systems Inc.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 9 Park Facility Improvements and Costs

3. Park Facility Improvements and Costs
This chapter estimates and documents the expected park and recreation facility needs that can be attributed to the housing growth documented in Chapter 2. It then estimates the corresponding costs associated with developing these park facilities. The cost estimates assume the City will not need to acquire new land to accommodate facility expansion needs (i.e., costs exclude land acquisition).

Existing Service Level Assumptions
This analysis relies on the estimates of existing parks and recreation service levels in the City as a basis for projecting the need for new facilities and improvements.

Existing service levels are based on the ratio of housing units to the number of parks and recreation facilities available to serve this population.

The existing service standard is summarized in Table 5 based on the approximately 14,500 housing units in Seal Beach as of 2021 (see Table 3 in Chapter 2). The residents in these units are served by a variety of community buildings, developed parkland, courts, and other facilities. Appendix Tables A-1, A-2, and A-3 provide a breakdown of all City-owned parks by facility type and by each individual park.

Table 5 Existing Park Facilities Service Level
Parks Facilities Existing Inventory1
Service Level Per
1k Housing Units2 Units
Community Buildings 16,500 1,137 square feet
Other Developed Parkland 72.9 5 acres
Fields 18.2 1 acres
Hard Courts 4.4 0.3 acres
Indoor Courts 4312.4 297.2 square feet
Soft Courts 1.7 0.1 acres
Other Buildings 15,296 1,054 square feet
Restrooms 4,290 296 square feet
Paved Parking 848 58 spaces
Gravel Parking 145 10 spaces
Pool 2,051 141 square feet
[1] For a detailed survey of the existing Seal Beach park facilities inventory, see the Appendix for Table A-1.
[2] Based on 1,243 new housing units, as shown in Table 3.

Source: City of Seal Beach; Economic & Planning Systems, Inc.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 10 Park Facility Improvements and Costs Facility Needs Attributable to Growth
The park and recreation capital facility needs attributable to new housing growth are based on projected housing development in the City applied to the existing service standard illustrated in Table 5. The City’s parks and recreation’s facility needs from new growth is shown below in Table 6. New population growth is expected to be served by a variety of parks and recreation facilities including community buildings, developed parkland, courts, fields, and other facilities.

Table 6 Park and Recreation Facility Needs Attributable to Growth New Park Facility Cost Estimates
The updated Parks Impact Fee is calculated based on the costs of developing or expanding facilities for new residents to meet adopted service standards. EPS worked with City staff to establish average per unit costs for each of these facility types. These cost estimates draw on EPS’s experience developing impact fee programs and working on similar park and recreation facilities across California. 1 To develop cost assumptions, EPS referenced a range of comparable projects, adjusting for local conditions such as geography and inflation. Park facility costs can vary significantly depending on design, level of finish, and material costs. 1 Park facility costs were used from a variety of EPS Park Fee Nexus Studies and other park development work. See Appendix Table A-5 for more details.

Parks Facilities Existing Inventory1
Attributable
to Growth2 Units
Community Buildings 16,500 1,413 square feet
Other Developed Parkland 72.9 6 acres
Fields 18.2 2 acres
Hard Courts 4.4 0.4 acres
Indoor Courts 4312.4 369.4 square feet
Soft Courts 1.7 0.1 acres
Other Buildings 15,296 1,310 square feet
Restrooms 4,290 367 square feet
Paved Parking 848 73 spaces
Gravel Parking 145 12 spaces
Pool 2,051 176 square feet
[1] For a detailed survey of the existing Seal Beach park facilities inventory, see the Appendix for Table A-1.
[2] Based on 1,243 new housing units, as shown in Table 3.

Source: City of Seal Beach; Economic & Planning Systems, Inc.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 11 Park Facility Improvements and Costs While actual costs may be higher or lower in specific cases, average values were used to ensure reasonable and consistent estimates.

As summarized in Table 7 the total cost of maintaining the current service standards is about $7.4 million. The cost estimates are provided in the Parks DIF CIP, detailed previously in Table 2 and in Appendix Table A-6. As described in the next chapter, the cost estimate for developing and / or expanding city’s park and recreation facilities is used to determine the maximum justifiable parks facilities fee.

Table 7 Parks Facility Capital Costs for New Development Parks Facilities
Cost Attributable
to Growth
Community Buildings 1,413 square feet $475 per square foot $671,307 Other Developed Parkland 6.2 acres $47,500 per acre $296,585 Fields 1.6 acres $950,000 per acre $1,480,945
Hard Courts 0.4 acres $2,375,000 per acre $900,162
Indoor Courts 369.4 square feet $2,300 per square foot $849,561 Soft Courts 0.1 acres $950,000 per acre $134,261
Other Building 1,310 square feet $475 per square foot $622,322 Restrooms 367 square feet $1,900 per square foot $698,160 Paved Parking 72.6 spaces $10,000 per space $726,374
Gravel Parking 12.5 spaces $5,000 per space $62,263
Pool 175.7 square feet $4,000 per square foot $702,699
Total $7,144,640
Source: Rider Levett Bucknall; City of Seal Beach; Economic & Planning Systems, Inc.

Attributable
to Growth1 Cost Assumptions2
[1] Space attributable to new growth calculations are found in Table 3. Totals may not sum due to rounding. [2] Cost assumptions reflect conservative estimates based on a variety of sources. See Appendix Table A-5 for further details.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 12 Nexus Findings and Fee Calculation

4. Nexus Findings and Fee Calculation
This chapter documents the Seal Beach Parks Impact Fee calculation as well as required nexus findings. Specifically, it demonstrates the "nexus" between new residential development in the City and the parks improvements needed to serve it, as required under AB 1600.

Park and Recreation Fee Calculation
The maximum park and recreation fee per housing unit is based on the aggregate fee program cost of $7.4 million (see Table 7) The fee program includes a two percent program administration fee, consistent with other Mitigation Fee Act program administrative costs in many other California jurisdictions and within the range noted in HCD’s template nexus study. This two percent administration cost is designed to cover expenses for preparation of the development impact fee and subsequent updates, as well as the required reporting, auditing, collection and other annual administrative costs involved in overseeing the program.

Fees Per Unit and Per Square Foot
EPS uses data on housing density (i.e., average people per household) to differentiate fee levels by housing type. Since single-family units on average have more people per household than multifamily units, the fee per unit is proportionately higher. Specifically, based on the most recent US Census based data for Seal Beach (2022 American Community Survey), single-family units average about 2.16 people per household compared to 1.49 for multifamily units.

Table 8 calculates the maximum supportable development impact fee for singlefamily and multifamily housing units, respectively. The maximum fee is calculated by multiplying the average cost per new resident by the density assumption of people per household by unit type (i.e., single-family or multifamily). This results in an average park and recreation DIF of $6,736 per single-family unit and $4,647 per multifamily unit.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 13 Nexus Findings and Fee Calculation Table 8 Calculation of Parks Impact Fee Per Square Foot Consistent with the requirements of AB 602, the per unit fee is converted into a fee that scales in proportion to unit square footage, so that the fee can be charged on a per square foot basis. The analysis assumes that the impact of residential development on parks facilities will scale by persons per household and that larger units can accommodate more people. To calculate the fee per square foot, EPS divided the cost per unit by average unit size (Table 4). The Cost Allocation Factor Formula (source)
Parks & Recreation
Fee Program
Facility Costs Allocated to Fee Program1 = a (see Table 7) $7,144,640 Housing Unit Growth = b (see Table 3) 1,243
Avg. Park Facilities Cost Per Unit2 c = ( a / b) *1.02 $5,863 City Average Household Size3 = d (see Table 4) 1.88
Single-Family = e (see Table 4) 2.16
Multifamily = f (see Table 4) 1.49
Avg. Cost Per Person g = c / d $3,119
Avg. Cost / Single-Family Unit h = g * e $6,736
Avg. Cost / Multifamily Unit i = g * f $4,647
Average Unit Sizes (square feet)4
Single-Family5 = j (see Table 4) 1,757
Multifamily6 = k (see Table 4) 861
Fee Per Square Foot
Single-Family = h / j $3.83
Multifamily = i / k $5.40
Source: ACS 5-Year Estimates; Redfin; CoStar Group; City of Seal Beach; Economic & Planning Systems, Inc. [1] For a breakdown of facility costs by facility type, see Table 7. [3] City average people per household calculated using 2022 ACS five-year estimates. [4] Both single- and multifamily unit data consists of the following municipalities: Cypress, Huntington Beach, Los Alamitos, Seal Beach, Stanton, and Westminster.
[5] Average single family units are calculated using newly built homes in the in the past five years using Redfin data. [6] Average multifamily units are sourced from CoStar Group from multifamily developments constructed in the past five years. [2] Two percent program administration fee applied to cost per unit.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 14 Nexus Findings and Fee Calculation maximum allowable park and recreation fee is $3.83 per square foot for singlefamily and $5.40 per square foot for multifamily. 2 It should be noted that there is no definitive data on how the number of people in a residential unit scale based on square footage. These variations are likely to evolve over time and by jurisdiction based on household formation patterns, available housing stock, demographic and economic changes, among other factors. The nexus analysis assumes that on average larger housing units will accommodate more people than smaller housing units but includes a maximum and minimum to reflect the fact that differences will likely be less pronounced at either end of the spectrum.

Maximum and Minimum Fee Levels
AB 602 requires that a nexus study must “either calculate a fee levied or imposed on a housing development proportionately to the square footage of the proposed units, or make specific findings explaining why square footage is not an appropriate metric to calculate the fees.” This nexus analysis assumes that park impacts will increase based on persons per household, which in turn are likely to be proportional to unit sizes (e.g., larger units typically have more bedrooms and can accommodate more people). However, EPS also finds that most new housing projects in the region encompass units that range from studios (mostly multifamily) to four bedrooms, structures that correspond to household sizes ranging from one to six people. Consequently, EPS has calculated a minimum and maximum fee level to capture the likely upper and lower bound of new housing’s per unit impact on park and recreation facilities.
3 Table 9 converts the total fees into a minimum and maximum per unit fee based on the typical range of unit sizes and/or average persons per household. The minimum and maximum fee for new single-family development is $3,119 and $18,711 per unit, respectively. The minimum and maximum fee for multifamily development is $3,119 and $15,593 per unit.

EPS utilized two approaches to calculate the maximum and minimum fees. The minimum fee for single-family units and multifamily units are set to equal the impact of one person per household. This ensures that no new unit is charged a fee that is less than the impact of the minimum household size (i.e., one person).

While it is likely that future housing developments may include smaller units than 2 The maximum allowable fee per square foot is rounded to the nearest $.01. 3 Pursuant to State law, the minimum fee amount excludes accessory dwelling units (UDUs) that are less than 750 square feet. ADUs that are less than 750 square feet are exempt from development impact fees. If an ADU is 750 square feet or larger, impact fees shall be charged proportionately in relation to the square footage of the ADU to the square footage of the primary dwelling unit. (Gov. Code, § 66324 subd. (c)(1).) In this specific instance, impact fees also include Quimby fees specified in Government Code section 66477 (Gov. Code, § 66324 subd. (c)(2)).

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 15 Nexus Findings and Fee Calculation those charged the minimum fee, the analysis assumes that their impact on park and recreation facilities will not be lower than that of a one-person household.

The maximum fee for single-family and multifamily units is based on the upper end of bedroom counts being built in the regional market and the associated persons per household for these units. Specifically, the analysis assumes a maximum park and recreation impact on single-family homes based on a four bedroom, six-person household. For multifamily units, the analysis is based on a three-bedroom, four-person household. Person per household sizes incorporate the Census Bureau’s definition of overcrowding, limiting one person per room excluding bathrooms, porches, balconies, foyers, halls, or half-rooms.

While larger units may accommodate more people, there is no consistent or proportional relationship between square footage and household size beyond a certain point. As a result, using square footage to calculate the maximum fee could overcharge units that are large but do not house more residents. Instead, this analysis applies a maximum household size to cap the fee, reflecting the upper limit of likely park usage generated by a single unit. This approach ensures the fee will not exceed the likely impact of housing on the City’s park and recreation facilities.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 16 Nexus Findings and Fee Calculation Table 9 Residential Maximum and Minimum Per Square Foot Conversion Nexus Findings
The Parks Impact Fee is applied to residential development to enable the City to meet its adopted service standards for parks facilities. Development impact fees can be charged to new development under the Mitigation Fee Act and require a specific set of nexus findings. A summary of the key nexus findings is provided below. The technical information and calculations provided in this Report support these nexus findings/requirements.

1. Identify the Purpose of the Fee. The purpose of the fee is to ensure that new development helps fund new parks and recreation facility capacity consistent with the service standards adopted by the City of Seal Beach.

Cost Allocation Factor Formula
Avg. Park Facility Cost / Person = a (see Table 8) $3,119 per person $3,119 per person Avg. Fee / Housing Sq. Ft. = b (see Table 8) $3.83 per sq. ft. $5.40 per sq. ft.

Avg. Persons / Household = c (see Table 4) 2.16 / Household 1.49 / Household Average Maximum1 d 6.00 / Household 5.00 / Household
Minimum2 e 1.00 / Household 1.00 / Household
Maximum and Minimum Fee Amounts / Unit
Average f = a * c $6,736 per unit $4,647 per unit
Minimum g = a * e $3,119 per unit $3,119 per unit
Maximum h = a * d $18,711 per unit $15,593 per unit
Units equal or less than3 = g / b 814 sq. ft. 578 sq. ft.

Units equal or greater than4 = h / b 4,882 sq. ft. 2,889 sq. ft.

Summary of Fee Amounts
Units between minimum and maximum size b $3.83 / sq. ft. $5.40 / sq. ft.

Units equal to or less than minimum size g $3,119 / unit $3,119 / unit Units equal to or greater than maximum size h $18,711 / unit $15,593 / unit Single-Family Multifamily
[1] Assumes largest units will be four bedrooms for a single-family unit and three-bedrooms for a multifamily unit, consistent with recent market trends. A typical standard for overcrowding is more than one person per room, based on the Census Bureau’s definition of “room,” which excludes bathrooms, porches, balconies, foyers, halls, or half-rooms.
[3] Represents the smallest unit size that could be used to calculate the minimum fee, derived by dividing the minimum per-unit fee by the average persquare-foot fee. [4] Represents the largest unit size that could be used to calculate the maximum fee, derived by dividing the maximum per-unit fee by the average persquare-foot fee.

Maximum and Minimum Unit Sizes Subject to
Variable Fee / Sq.Ft.
[2] Assumes all units will have at least one person per household.

Source: ACS 5-Year Estimates; Redfin; CoStar Group; City of Seal Beach; Economic & Planning Systems, Inc.

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Economic & Planning Systems, Inc. 17 Nexus Findings and Fee Calculation

2. Identify the Use to which the Fee is to be Put. The fee revenues will be used to improve and expand parks facilities.

3. Determine how there is a reasonable relationship between the fee’s use and the type of development project on which the fee is imposed. New development associated with housing growth will require additional parks facilities consistent with existing service levels by the City. The fee revenues will be used to expand the City’s existing parks’ facilities capacity in order to meet this need.

4. Determine how there is a reasonable relationship between the need for the public facility and the type of development project on which the fee is imposed.

The existing per capita service levels for the provision of park facilities in Seal Beach are applied to projected housing development in the City and, based on assumptions related to average persons per household by type of development, are used to estimate future facility needs attributable to growth. The use of these established standards ensures a reasonable relationship between the land uses paying the fees and the parks facilities.

5. Determine how there is a reasonable relationship between the amount of the fee and the cost of the public facility or portion of the public facility attributable to the development on which it is imposed. The level of the fee is based on the combination of City park facility service standards and current estimates of the costs of providing the additional park facilities required. The technical analysis ensures that the fee schedule (amount of the fee) is directly and proportionally tied to the costs of the parks facilities.

AB 602 Compliance
The updated fee calculations have followed the new requirements of AB 602 in addition to the pre-existing requirements of the Mitigation Fee Act. This chapter describes the ways the analysis complies with key sections of AB 602. There are other compliance components related to implementation and administration of the fee program (such as posting program-related documents online) that the City will oversee.

Capital Improvement Plan
AB 602 requires that jurisdictions adopt a capital improvement plan (CIP) as part of the nexus report process to identify improvements that will contribute towards expanding the City’s parks and recreation facility capacity that will subsequently serve new residents. Accordingly, this Report relies, in part, on the Parks Fee CIP detailed in Appendix Table A-6. The City will adopt the Parks Fee CIP at the same time as the fee ordinance adoption through a resolution. A key purpose of the CIP is to indicate the types of improvements that will be funded in part by the fee program.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 18 Nexus Findings and Fee Calculation As shown, the Parks DIF CIP includes a total investment of approximately $7,429,919. While the updated impact fees will provide funding to support the City’s parks improvement plans, actual impact fee revenues collected is uncertain and will depend on the level of new development in the city. As is common, impact fee revenue will only fund a portion of the City’s overall parks improvement program and the City will identify additional funding sources to support these improvements, which may include other City revenues and grants.

Explanation of Level of Service
AB 602 requires that the nexus study indicate whether the fee calculation is based on existing levels of service or on different levels of service, and to provide an explanation if the latter. As indicated in Table 5 in Chapter 2, the City currently provides an existing service level for community buildings, developed parkland, courts, and other facilities per 1,000 housing units.

In the 2013 Parks and Community Services Master Plan, the City recognized it would neither meet the Statewide Standard of 5 acres of parkland per 1,000 people including community parks and neighborhoods parks, nor reach the Municipal Code goal. The City found the actual ratio of combined and neighborhood parks was 3.12 acres of parkland per 1,000 people. The City also recognized that a high percentage of the city was developed before the adoption of the current acreage goal and that it is unlikely to develop further parkland.

Consequently, the City looks to refer to the relationship between the current park and recreation facilities and new housing growth as a more appropriate standard.

The City believes new development should contribute towards the cost of meeting the City’s existing service levels standards of facilities, rather than the previously adopted level of service that referred to park acreage. As a result, the existing service levels are used to develop the maximum updated fee levels.

Original Nexus Study
AB 602 states that “if a nexus study supports the increase of an existing fee, the local agency shall review the assumptions of the nexus study supporting the original fee and evaluate the amount of fees collected under the original fee.” The City has not previously conducted a nexus study and has instead relied on the Quimby Act to establish its service standard and current parks and recreation fee.

The current parks fee applies to units that create a net increase to the City’s housing stock. This fee is set to $10,000 per single-family dwelling unit and $5,000 for other residential users (each residential unit that is not a single-family dwelling).

In addition, the City did not have an adopted service standard for other types of parks and recreation facilities at the time of the original fee adoption. However, this report documents the City’s existing service levels for a range of facilities (as shown in Table 5). Therefore, it is reasonable to include the costs for providing

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 19 Nexus Findings and Fee Calculation these facilities in a formally adopted park and recreation CIP to new residents in the calculation of the updated fee.

Residential Fee to be Charged in Proportion to Unit Size AB 602 requires that a nexus report “calculate a fee imposed on a housing development project proportionately to the square footage of proposed units of the development.” As described in Chapter 4, the updated fee schedule provides a fee that is charged proportionally on a per square foot basis for single-family units between 814 and 4,882 square feet and multifamily units between 578 and 2,889 square feet. Given nexus considerations described herein, EPS recommends a flat per unit fee for housing projects that fall outside these ranges. Findings on how this recommendation addresses the requirements of AB 602 are provided below.

1. Findings for why square footage is not an appropriate metric for dwelling units that are larger or smaller than the maximum or minimum range specified in this study. EPS finds that the average long-term occupancy for multi-family and single units is unlikely to contain more than five (5) and six (6) people, respectively. Thus, the maximum allowable fee should not exceed the impact of five people for a multi-family unit and six people for a single-family unit, regardless of their respective square footage. EPS also finds that all housing units have a minimum impact on park and recreation facilities that is equal to that of a one-person household (i.e., all dwelling units will accommodate at least one person). Thus, the minimum fee should not fall below the amount that covers the impact of a one-person household.

2. Findings that the fee program provides an alternative basis for calculating fees for dwelling units that are larger or smaller than the maximum or minimum range specified in this study. This nexus study provides an alternative methodology for calculating an appropriate fee for dwelling units at the low and high end of the square footage spectrum that is based on the long-term average maximum and average minimum number of people likely to occupy these units. This methodology sets the minimum fee equal to the impact of a one-person household and the maximum fee equal to the impact of a five- and six-person household for multi-family and single-family units, respectively.

3. Findings that ensure smaller developments are not charged disproportionate fees. This nexus study calculates fees that decline in proportion to unit size (i.e., smaller units pay less) within a range that covers the average, longterm projected maximum and minimum people per household for singleand multi-family units respectively. No units will be charged a fee that exceeds the maximum amount that corresponds to the long-term average people per household for that unit size and type. Likewise, no units will be charged less than the fee amount corresponding to a one-person household, the minimum potential impact of a new dwelling unit.

SEAL BEACH PARKS IMPACT FEE UPDATE NEXUS STUDY
Economic & Planning Systems, Inc. 20 Nexus Findings and Fee Calculation Appendix A
Table A-1 (1 of 2)
Aggregated Facility Inventory (1/2)
Seal Beach Park Fee; Project # 244007
Park Facilities Source
Community Buildings
Marina Community Center 4,600 square feet Facility Condition Assessment Study Seal Beach Tennis and Pickleball Center 4,314 square feet Facility Condition Assessment Study North Seal Beach Community Center 4,550 square feet Facility Condition Assessment Study Zoeter Building (Day Care) 1,500 square feet Facility Condition Assessment Study Seal Beach Senior Center 1,536 square feet City of Seal Beach Total 16,500 square feet
Developed Parkland 171.05 acres Parks Master Plan
Beach and Pier Area 73.3 acres
Facility and Field Space 24.9 acres Sum of all other park land and buildings Other Developed Parkland1 72.9 acres
Fields2
Lighted Baseball Fields 1 fields 1 acres/field Parks Master Plan; EPS Professional Experience Unlit Baseball Fields 0 fields 1 acres/field Parks Master Plan; EPS Professional Experience Lighted Softball Fields 1 fields 1 acres/field Parks Master Plan; EPS Professional Experience Unlit Softball Fields 3 fields 1 acres/field Parks Master Plan; EPS Professional Experience Lighted Multipurpose Fields 1 fields 1.65 acres/field Parks Master Plan; EPS Professional Experience Unlit Multipurpose Fields 2 fields 1.65 acres/field Parks Master Plan; EPS Professional Experience Lighted Soccer Fields 0 fields 1.65 acres/field Parks Master Plan; EPS Professional Experience Unlit Soccer Fields 5 fields 1.65 acres/field Parks Master Plan; EPS Professional Experience Total 18.2 acres
Hard Courts
Tennis Courts 17 courts 0.15 acre/court City Communications; EPS Professional Experience Pickelball Courts 26 courts 0.04 acre/court City Communications; EPS Professional Experience Lighted Handball Courts 2 courts 0.15 acre/court Parks Master Plan; EPS Professional Experience Unlit Handball Courts 0 courts 0.15 acre/court Parks Master Plan; EPS Professional Experience Lighted Basketball Courts 2 courts 0.15 acre/court Parks Master Plan; EPS Professional Experience Unlit Basketball Courts 2 courts 0.15 acre/court Parks Master Plan; EPS Professional Experience Total 4.4 acres
Information Provided Conversion Used
Source: Seal Beach Facility Condition Assessment Study; Seal Beach Parks & Community Services Master Plan (2013); Economic & Planning Systems, Inc. [1] Includes park park acres with a vatiety of improvements and minor facilities (e.g., picnic tables, play structures, pathways, fencing, and hardscape). [2] McGaugh fields are not included in a joint use agreement with the City.

Table A-1 (2 of 2)
Aggregated Facility Inventory (2/2)
Seal Beach Park Fee; Project # 244007
Park Facilities Source
Indoor Courts
Indoor Basketball Courts 1 courts 6534 square feet/court Parks Master Plan; EPS Professional Experience Less Joint Use Facility1 (2,222) square feet
Total 4,312 square feet
Soft Courts
Volleyball Courts 11 courts 0.15 acre/court Parks Master Plan; EPS Professional Experience Total 1.65 acres
Other Buildings
Beach Facility-Maintenance Building 3,150 square feet Facility Condition Assessment Study Beach Facility-Storage Bldg. 350 square feet Facility Condition Assessment Study Lifeguard Garage 2,250 square feet Facility Condition Assessment Study Lifeguard Headquarters 1,900 square feet Facility Condition Assessment Study Lifeguard Tower 516 square feet Facility Condition Assessment Study McGaugh Pool Mechanical Room 430 square feet City Staff Storage Shed 5 sheds 350 square feet Storage estimate; Parks Master Plan Total Shed Area 1750 square feet
Other Buildings 2 buildings Building estimates via Google Earth; Parks Master Pla Other Buildings Area 4950 square feet
Total 15,296 square feet
Restrooms2
Beach Facility-Restroom Building 850 square feet Facility Condition Assessment Study Seal Beach Pier Restrooms 860 square feet Facility Condition Assessment Study Restrooms 6 restrooms 430 square feet Restroom estimate; Parks Master Plan Park Restroom Area 2,580 square feet
Total 4,290 square feet
Parking
Paved/Striped Parking Spaces 141 spaces 325 square feet Parks Master Plan, City Communications Paved/Striped Parking Spaces, Other Lot 688 spaces 325 square feet Parks Master Plan, City Communications Less Joint Use Facility1 (19) spaces Facility Condition Assessment Study Total 848 spaces
Gravel Parking Areas 145 spaces Parks Master Plan, Google Earth Total 145 spaces
Pools
McGaugh L-Shaped Pool 2051 square feet Parks Master Plan Total 2,051 square feet
Source: Seal Beach Facility Condition Assessment Study; Seal Beach Parks & Community Services Master Plan (2013); Economic & Planning Systems, Inc.

Information Provided Conversion Used
[1] There is one facility are shared between the City of Seal Beach and local schools, the McGaugh Elementary School Gymnasium. EPS calculated the school-related use of the gymansium to ensure proportional costs attributable to new development are accurately reflected. For further details, see Table A-2. [2] This count excludes restrooms in the Seal Beach Tennis and Pickleball Center and North Seal Beach Community Center as those restrooms are assumed to be part of community building square footage.

Table A-2
Park Facility Inventory of Joint-Use Facilities
Seal Beach Park Fee; Project # 244007
Joint Use Facility
McGaugh Gymnasium2
Indoor Basketball Court 1 court
Indoor Basketball Court 6534 square feet 6534 square feet/court 2,222 square feet Paved/Striped Parking Spaces 56 spaces 19 spaces
Source: City of Seal Beach; Economic & Planning Systems, Inc.

Itemized Facility Area Conversion Used
School Utilization
Rate1
[2] School utilization rates were provided by the City of Seal Beach. The McGaugh Gymnasium has a school/non-public utlization rate of 34%. [1] School utilization rates are used to reduce service standard and amount attributable to growth and demand attributed to population growth.

Table A-3
Park Facility Inventory
Seal Beach Park Fee; Project # 244007
Community Buildings
Restrooms
Portable Toilets
Storage Shed
Other Buildings
Lighted Baseball Fields
Unlit Baseball Fields
Lighted Softball Fields
Unlit Softball Fields
Dugout Bench
Bleachers
Volleyball Courts
Lighted Multipurpose Fields
Unlit Multipurpose Fields
Lighted Soccer Fields
Unlit Soccer Fields
Lighted Tennis Courts
Unlit Tennis Courts
Lighted Pickelball Courts
Unlit Pickelball Courts
Lighted Handball Courts
Unlit Handball Courts
Indoor Basketball Courts
Lighted Basketball Courts
Unlit Basketball Courts
Tetherball
Wading Pools
Snack Bars
Tot Lot/Playgrounds
Swing Sets
Park Benches
Picnic Shelters
Picnic Tables
Barbecues
Horseshoe Pits
Shuffleboard Courts
Drinking Fountain
Trash Receptacles
Skate Parks
Pet Waste Dispenser
Bike Racks
Park Sign
General Security Lighting
Paved/Striped Parking Spaces
Gravel Parking Area
Almond Park 1.80 1 4 1 1 1 2 3 1 3 Y 1
Arbor Park 9.60 4 1 2 1 5 1 2 Y
Arbor Dog Park 1.40 1 6 2 13 9 2 Y
Aster Park 0.60 2 3 1
Blue Bell Park 1.30 1 1 1 3 1 4 1 3 1 Y
Corsair Park 0.30 1
Edison Park 27.00 1 1 2 2 Y 1 1 1 1 1 2 5 1 5 2 16 Y 1 Y 6 Y Eisenhower Park 1.50 1 1 1 18 13 Y
Electric Avenue Greenbelt 8.90 38 1 3 20 1
Gum Grove Nature Park 10.50 1 1 5 2 1 Y
Gum Grove Nature Park Expansion 14.50 1 10
Heather Park 1.60 1 1 1 2 1 1 4 1 6 1 6 Y 1
Marina Park & Community Center Schooner Park 1.50 1 1 1 1 4 0 2 1 1 1 14 1 2 1 18 Y 1 37 Y Schooner Park 0.60 1
Seal Beach Tennis and Pickleball Center 7.00 1 1 1 8 1 20 1 1 42 5 35 1 68 Windsurf Park 0.40 1 3 4 2 6 Y 1 Y
Zoeter Greenbelt 1.20
Zoeter Field 1.80 1 1 1 1 2 Y 1 2
North Seal Beach Community Center 1.20 1 1 1 3 Y
Seal Beach Senior Center 0.25 1 1 1 3 Y 16
Community Aquatics Center/McGaugh School 1 1 1 Y 1 2 6 Y Y McGaugh School Fields/Tennis Courts 2 3 1 0 3
Beach and Pier Area 73.30 10 1 Y
River's End Park (Ocean Park Development) 4.80 1 22 1 9 2 15 5 2 1 Totals 171.1 4 8 7 5 4 1 0 1 3 6 0 11 1 2 0 5 13 4 25 1 2 0 1 2 2 1 0 1 8 6 168 6 44 0 0 0 20 167 0 17 2 11 0 141 0 Source: City of Seal Beach; Economic & Planning Systems, Inc.

Park Park Acreage
Facility Type
Table A-4
Regional Housing Needs 2021-2029
Seal Beach Park Fee; Project # 244007
Income Level Housing Needs
Very Low1 258
Low 201
Moderate 239
Above Moderate 545
Total 1,243
Source: City of Seal Beach 6th Cycle Housing Element 2021 - 2029; Economic & Planning Systems, Inc.
[1] Includes extremely low households, estimated to one-half the very low need (129 units)
Table A-5
Cost Assumption Overview
Seal Beach Park Fee; Project # 244007
Parks Facilities Sources With Comparable Cost Estimates Community Buildings $475 per square foot 2024 Signal Hill Civic Center Master Plan; 2025 Public Draft Fresno Southeast Development Area Specific Plan (SEDA) Public Facilities Financing Plan (PFFP); 2025 Public Draft Oceanside Parks and Rec Nexus Study; 2025 Folsom Plan Area Nexus Study for Public Facilities; Westminster Park and Recreation Facilities Master Plan
Other Developed Parkland $47,500 per acre 2024 Pleasanton Capital Facilities Nexus Study; 2025 Public Draft Fresno SEDA PFFP; 2025 Fresno Parks Nexus Study Cost Estimates
Fields $950,000 per acre 2024 Pleasanton Capital Facilities Nexus Study; 2025 Draft Union City Nexus Study Hard Courts $2,375,000 per acre 2024 Pleasanton Capital Facilities Nexus Study; 2025 Public Draft Oceanside Parks and Rec Nexus Study; 2025 Draft Union City Nexus Study; Westminster Park and Recreation Facilities Master Plan Indoor Courts $2,300 per square foot 2025 Draft Union City Nexus Study; 2025 Public Draft Oceanside Parks and Rec Nexus Study; 2025 Folsom Plan Area Nexus Study for Public Facilities
Soft Courts $950,000 per acre 2024 Pleasanton Capital Facilities Nexus Study; 2025 Draft Union City Nexus Study Other Building $475 per square foot 2024 Pleasanton Capital Facilities Nexus Study; 2025 Folsom Plan Area Nexus Study for Public Facilities; Rider Levett Bucknall (RLB)
Restrooms $1,900 per square foot 2024 Pleasanton Capital Facilities Nexus Study; 2025 Draft Union City Nexus Study; 2025 Public Draft Oceanside Parks and Rec Nexus Study
Paved Parking $10,000 per space RLB; 2025 Folsom Plan Area Nexus Study for Public Facilities Gravel Parking $5,000 per space EPS "rule of thumb" used in multiple studies [minimal impact on total level] Pool $4,000 per square foot Cities of Mountain View, Piedmont, South San Francisco, Santa Ana, Alameda Source: Rider Levett Bucknall; City of Seal Beach; Economic & Planning Systems, Inc.

Cost Assumptions2
Table A-6
Parks DIF Capital Improvement Program
Seal Beach Park Fee; Project # 244007
Type/Project Location Time of
Availability DIF Attributable Cost Source for Cost1 Appropriating Funds Community Buildings TBD/Citywide 2026-2040 $671,307 City Staff and EPS Research DIF and other sources Other Developed ParklandTBD/Citywide 2026-2040 $296,585 City Staff and EPS Research DIF and other sources Fields TBD/Citywide 2026-2040 $1,480,945 City Staff and EPS Research DIF and other sources Hard Courts TBD/Citywide 2026-2040 $900,162 City Staff and EPS Research DIF and other sources Indoor Courts TBD/Citywide 2026-2040 $849,561 City Staff and EPS Research DIF and other sources Soft Courts TBD/Citywide 2026-2040 $134,261 City Staff and EPS Research DIF and other sources Other Building TBD/Citywide 2026-2040 $622,322 City Staff and EPS Research DIF and other sources Restrooms TBD/Citywide 2026-2040 $698,160 City Staff and EPS Research DIF and other sources Paved Parking TBD/Citywide 2026-2040 $726,374 City Staff and EPS Research DIF and other sources Gravel Parking TBD/Citywide 2026-2040 $62,263 City Staff and EPS Research DIF and other sources Pool TBD/Citywide 2026-2040 $702,699 City Staff and EPS Research DIF and other sources Total $7,144,640
[1] See Appendix Table A-5 for a more detailed cost sourcing.

Source: City of Seal Beach; Economic & Planning Systems, Inc.

The Economics of Land Use
800 Wilshire Boulevard, Suite 410  Los Angeles, CA 90017 213.489.3838  www.epsys.com

SEAL BEACH PARKS

DEVELOPMENT

IMPACT FEE NEXUS
STUDY
November 10, 2025
Economic & Planning Systems, Inc. Development Impact Fees Overview 1 AGENDA
• About EPS
• Development Impact Fee Overview
• Nexus Study Results
• Fee Comparison to Local Jurisdictions
Economic & Planning Systems, Inc. Development Impact Fees Overview 2

ABOUT ECONOMIC & PLANNING SYSTEMS
• Founded in 1983, offices
in LA, Oakland, and
Sacramento
• National practice
implementing
comprehensive public
financing strategies,
including development
impact fees
Economic & Planning Systems, Inc. Development Impact Fees Overview 3

EPS DEVELOPMENT IMPACT FEE EXPERIENCE
Long Beach Comprehensive Fee Update
Paramount Comprehensive Fee Update
Vacaville Comprehensive Fee Update
Belmont Comprehensive Development Impact Fee
Program
Foster City Comprehensive Fee Update
Pleasanton Comprehensive Fee Update
Burbank Public Facilities Nexus Study
Fairfield Capital Facility Fee
Turlock Capital Facilities Fee Nexus
Newark Public Facilities Impact Fee Study
Madera Public Facilities Impact Fee Study
Union City Capital Facilities Program and Fee
Alameda Capital Facilities Fee Program
Carlsbad Multimodal Transportation Fee Nexus Study
Orange Transportation System Improvement Fee
Fresno Major Street Impact Fee Nexus Study
Grass Valley Traffic Impact Fee Program Nexus Study
Dublin Downtown Transportation Impact Fee Update
East Contra Costa Regional Transportation Impact Fee
San Joaquin Regional Transportation Impact Fee Program
Coachella Valley Regional Transportation Fee Program
Solano County Regional Transportation Fee Program
Ukiah Regional Transportation Fee
Cupertino Traffic Impact Fee & Nexus Study
West Hollywood Transportation Impact Fee
West Los Angeles Regional Transportation Nexus Study
Culver City TDFM & Mobility Improvement Fee
Comprehensive Development Impact Fee Programs
Santa Rosa Capital Facilities Fee
South San Francisco Public Facilities Impact Fee
Nexus Study
Westminster Comprehensive Impact Fee Study
Calistoga Comprehensive Impact Fee Nexus Study
Antioch Public Facilities and Transportation Nexus
Study
Martinez Comprehensive Development Impact Fee
Solano County Comprehensive Impact Fee Study
Fresno Comprehensive Impact Fee Study
West Covina Public Facilities Fee Program
San Luis Obispo Infrastructure Financing Analysis
Benicia Comprehensive Fee Program
San Bruno Comprehensive Fee Program
Woodland Major Projects Financing Plan and Fee
Nexus Study
Parks & Recreation Development Impact Fees
Transportation Development Impact Fees
Santa Monica Parks & Recreation Linkage Fee Nexus Study Redwood City Parks and Recreation Development Impact
Fee
Martinez Road and Parks Impact Fee Study

OVERVIEW OF DEVELOPMENT IMPACT FEES
Economic & Planning Systems, Inc. Development Impact Fees Overview 5 WHAT ARE DEVELOPMENT IMPACT FEES?
• One-time fee are paid by new development to fund the public infrastructure needs of new residents and workers
Economic & Planning Systems, Inc. Development Impact Fees Overview 6 WHAT ARE DEVELOPMENT IMPACT FEES?
• One-time fee are paid by new development to fund the public infrastructure needs of new residents and workers
• Fees CAN fund:
– New public infrastructure and facility projects that serve growth – Remodel/improve existing public infrastructure to expand capacity Economic & Planning Systems, Inc. Development Impact Fees Overview 7 WHAT ARE DEVELOPMENT IMPACT FEES?
• One-time fee are paid by new development to fund the public infrastructure needs of new residents and workers
• Fees CAN fund:
– New public infrastructure and facility projects that serve growth – Remodel/improve existing public infrastructure to expand capacity • Fees CANNOT fund:
– Fixing a deficiency in level of service to existing residents – Operations and maintenance costs
– Personnel costs (e.g., salaries, benefits)
Economic & Planning Systems, Inc. Development Impact Fees Overview 8 WHAT ARE DEVELOPMENT IMPACT FEES?
• One-time fee are paid by new development to fund the public infrastructure needs of new residents and workers
• Fees CAN fund:
– New public infrastructure and facility projects that serve growth – Remodel/improve existing public infrastructure to expand capacity • Fees CANNOT fund:
– Fixing a deficiency in level of service to existing residents – Operations and maintenance costs
– Personnel costs (e.g., salaries, benefits)
• Differ from user fees or permit fees, which are limited to covering the cost of a specific service or regulatory function
Economic & Planning Systems, Inc. Development Impact Fees Overview 9

EXISTING VS PROPOSED PARK FEE
Existing Fee (Quimby Act)
• The City’s current Park Impact Fee is
established under the Quimby Act
• Multifamily units generally exempt from
Quimby Act
• Fees are used to acquire additional
parkland
• Little to no parkland available in the City
Updated Fee (Mitigation Fee Act)
• The new fee would be established under
the Mitigation Fee Act
• Fees are used for improvements to
expand and improve capacity based on
new growth
• New fee will be per square foot, not by
unit
Economic & Planning Systems, Inc. Development Impact Fees Overview 10

HOW THE PARK IMPACT FEE IS CALCULATED
Cost of Park Facilities
Attributable to Growth
Projected Housing
Growth in City
Fee Per
Housing
Unit
Avg
Single-Family
Unit Fee
Avg
Multifamily
Unit Fee
Fee Per
Single-Family
Sq. Ft.

Fee Per
Multifamily
Sq. Ft.

Economic & Planning Systems, Inc. Development Impact Fees Overview 11 Collect Data on Capital Improvement Projects
Establish Growth Projections for City
Calculate Nexus-Based Fee for Residential Development
Develop Nexus Report and Receive Feedback
Present Fee Options to Council for Consideration and Adoption

STUDY PROCESS

NEXUS FEE STUDY RESULTS
Economic & Planning Systems, Inc. Development Impact Fees Overview 13

PARK IMPACT FEE CALCULATION
Cost of Park
Facilities
Attributable to
Growth
$7,144,640
Projected Housing
Growth in City
1,243 units
Fee Per
Housing
Unit
$5,863
Avg
Single-Family
Unit Fee
$6,736
Avg
Multifamily
Unit Fee
$4,647
Fee Per
Single-Family
Sq. Ft.
$3.83
Fee Per
Multifamily
Sq. Ft.
$5.40
Maximum fee that can be legally charged – City
can charge a lower amount
Economic & Planning Systems, Inc. Development Impact Fees Overview 14

CAPITAL IMPROVEMENT PLAN
Parks Facilities
Existing
Inventory
Attributable
to Growth
Cost
Assumptions
Cost Attributable
to Growth
Community Buildings (Sq. Ft.) 16,500 1,413 $475 $671,307 Other Developed Parkland (Acres) 72.9 6.2 $47,500 $296,585 Fields (Acres) 18.2 1.6 $950,000 $1,480,945
Hard Courts (Acres) 4.4 0.4 $2,375,000 $900,162
Indoor Courts (Sq. Ft.) 4312.4 369.4 $2,300 $849,561
Soft Courts (Acres) 1.7 0.1 $950,000 $134,261
Other Building (Sq. Ft.) 15,296 1,310 $475 $622,322
Restrooms (Sq. Ft.) 4,290 367 $1,900 $698,160
Paved Parking (Spaces) 848 72.6 $10,000 $726,374
Gravel Parking (Spaces) 145 12.5 $5,000 $62,263
Pool (Sq. Ft.) 2,051 175.7 $4,000 $702,699
Total $7,144,640
Source: Rider Levett Bucknall; City of Seal Beach; Economic & Planning Systems, Inc.

FEE COMPARISONS
Economic & Planning Systems, Inc. Development Impact Fees Overview 16

COMPARISON TO EXISTING FEE
Existing Fee (Quimby Act)
• Current Fees (non-subdivision):
– Single-Family Unit: $10,000 per
dwelling unit
– Other Residential Unit: $5,000 per
dwelling units
Updated Fee (Mitigation Fee Act)
• Single Family Unit:
– $3.83 Sq. Ft.
– $6,736 per average unit (~1,757 SF)
• Multifamily:
– $5.40 Sq. Ft.
– $4,647 per average unit (~861 SF)
Economic & Planning Systems, Inc. Development Impact Fees Overview 17

PEER CITIES FEE PER UNIT COMPARISON
* Fee assessed per square foot; fee shown is based on average unit size for Seal Beach (1,757 sq. ft. for single family, 861 for multifamily)
Jurisdiction Single Family Multifamily
Seal Beach (current) $11,463 $5,960
Seal Beach (proposed max)* $8,192 $5,609
Westminster $14,640 $10,158
Torrance $8,974 $7,628
Huntington Beach $20,705 $16,763
Garden Grove* $19,929 $15,987
Costa Mesa $14,073 $13,829
West Anaheim $17,503 $13,386
East Anaheim $16,279 $12,092
Stanton $1,357 $1,049
Placentia* $15,185 $13,203
Santa Ana* $5,630 $2,217

QUESTIONS AND COMMENTS

APPENDIX
Economic & Planning Systems, Inc. Development Impact Fees Overview 20

ANTICIPATED GROWTH
Housing Type Number of Units
Housing Units
Existing Inventory1 14,512
RHNA Allocations2 1,243
Anticipated Housing Inventory 15,755
Percent Change 9%
[1] Existing housing inventory based on 2021 housing unit estimates from the California DOF.
[2] Buildout housing inventory based on the City of Seal Beach 6th Cycle Housing Element 2021 - 2029.

Source: City of Seal Beach; Economic & Planning Systems, Inc. • New growth in the City is based
on forecasted residential growth
from the City’s Housing Element
• City’s housing growth is
anticipated to grow about 9%
Agenda Item H

AGENDA STAFF REPORT
DATE: November 10, 2025
TO: Honorable Mayor and City Council
THRU: Patrick Gallegos, City Manager
FROM: Michael Henderson, Chief of Police
SUBJECT: Approval of Updated Job Specification for Crossing Guard Classification
________________________________________________________________ SUMMARY OF REQUEST:

That the City Council adopt Resolution 7713 approving an updated job specification for the Crossing Guard (Part-Time) classification.

BACKGROUND AND ANALYSIS:

The City of Seal Beach periodically reviews position descriptions to ensure alignment with operational needs and best practices. As part of this routine maintenance, the Crossing Guard (Part-Time) specification has been reviewed to reflect contemporary staffing flexibility within the Support Services environment while preserving the position’s primary school-crossing safety mission.

Operational Need for Ancillary Support:

During school-calendar off hours, school breaks, weather-related suspensions, or temporary post closures, Crossing Guards may be available for short, supervised assignments that support the Records Bureau’s non-sensitive workload (e.g., non-CLETS data entry, document scanning, clerical/front-counter assistance, and internal routing). The updated specification adds an explicit language to formalize this practice while codifying clear access limitations.

Precedent:
• COVID-19 (2020–2022): During the pandemic, Crossing Guards were temporarily reassigned to assist with non-sensitive Records Bureau tasks, demonstrating the feasibility and value of this cross-utilization. • VIPS Program: SBPD Volunteers (VIPS) routinely assist with similar nonsensitive Records functions. Enabling Crossing Guards to perform these same tasks—under supervision and without access to secured systems— provides predictable surge capacity during peak periods and improves customer service continuity.

Safeguards and Boundaries:
• No access to modules containing sensitive information, evidence systems, jail/booking, ALPR, body-worn video, or any secured databases. • Tasks are clerical and non-sensitive in nature, performed under direct supervision with appropriate orientation (e.g., records handling basics, confidentiality awareness).
• This update does not change the position’s primary duty—safe pedestrian crossings for schoolchildren—nor does it expand the classification to any sworn or sensitive records functions.

The proposed language clarifies expectations, captures established practice, and enhances operational resiliency without creating a new position or altering the City’s staffing levels.

ENVIRONMENTAL IMPACT:

There is no environmental impact related to this item.

LEGAL ANALYSIS:

No legal analysis is required for this item.

FINANCIAL IMPACT:

No fiscal impact. This action updates the job specification only; no additional FullTime Equivalent employees are being added. Existing Crossing Guard hours/budget authority remain unchanged.

STRATEGIC PLAN:

This item is not applicable to the Strategic Plan.

RECOMMENDATION:

That the City Council adopt Resolution 7713 approving an updated job specification for the Crossing Guard (Part-Time) classification.

SUBMITTED BY: NOTED AND APPROVED:

Michael Henderson Patrick Gallegos
Michael Henderson, Chief of Police Patrick Gallegos, City Manager Prepared by: Nick Nicholas, Support Services Bureau Captain

ATTACHMENTS:

A. Resolution 7713
B. Crossing Guard Updated Job Specification
RESOLUTION 7713

A RESOLUTION OF THE SEAL BEACH CITY COUNCIL APPROVING THE JOB

SPECIFICATION FOR CROSSING GUARD (PART-TIME)
WHEREAS, the City of Seal Beach currently has the position of Crossing Guard (Part-Time); and,
WHEREAS, the requirements and responsibilities of this classification should be clarified and updated to reflect current operational needs of the Seal Beach Police Department (SBPD), including the ability to assign ancillary, non-sensitive tasks during periods when crossing assignments are not active; and, WHEREAS, the updated job specification maintains the position’s primary duty to provide for the safe crossing of schoolchildren and the public at designated locations, and further clarifies that other duties may be assigned based on the needs of the SBPD, including but not limited to non-CLETS records entry, document scanning, clerical/front-counter support, internal mail/records routing, and customer service, performed under supervision; and, WHEREAS, the updated job specification expressly prohibits access to secured or sensitive systems or information (including, but not limited to, CLETS/CJIS, evidence systems, jail/booking, ALPR, body-worn video, or any restricted databases); and,
WHEREAS, City Council is the only governing body who can approve job specifications.

NOW, THEREFORE, the Seal Beach City Council does resolve, declare, determine, and order as follows:

Section 1. The City Council hereby approves the updated job specification of the Crossing Guard (Part-Time).

PASSED, APPROVED, AND ADOPTED by the Seal Beach City Council at a regular meeting held on the 10th day of November 2025 by the following vote:

AYES: Council Members
NOES: Council Members
ABSENT: Council Members
ABSTAIN: Council Members

Lisa Landau, Mayor
ATTEST:

Gloria D. Harper, City Clerk
STATE OF CALIFORNIA }
COUNTY OF ORANGE } SS
CITY OF SEAL BEACH }
I, Gloria D. Harper, City Clerk of the City of Seal Beach, do hereby certify that the foregoing resolution is the original copy of Resolution 7713 on file in the office of the City Clerk, passed, approved, and adopted by the City Council at a regular meeting held on the 10th day of November 2025.

Gloria D. Harper, City Clerk
Crossing Guard
Department/Division: Police/Support Services
Reports To: Police Services Manager
Provides Direction To: N/A
FLSA Exemption Status: Non-Exempt
Date Prepared: November 10, 2025
Date Adopted by City Council: November 10, 2025
Class Concept
The Crossing Guard position is a part-time position, approximately five hours per day, two (2) hours in the morning and three (3) hours in the afternoon, Monday through Friday.

Crossing Guards work during the school year (September through June), or at other times based on the needs of the Seal Beach Police Department. Applicants must be able to work outdoors and have reliable transportation or ability to report to assignments consistently.

Crossing Guards work under the general direction of the Police Services Manager within the Seal Beach Police Department. Based on the needs of the City, a flexible schedule may be assigned for either a morning or afternoon shift or a combination thereof, or for specific weekdays, based on the availability of the Crossing Guards and at the discretion of the Police Services Manager. Other duties may be assigned based on the needs of the Seal Beach Police Department, including but not limited to non-CLETS records entry, scanning, clerical, etc.

Agenda Item I

AGENDA STAFF REPORT
DATE: November 10, 2025
TO: Honorable Mayor and City Council
THRU: Patrick Gallegos, City Manager
FROM: Michael Henderson, Chief of Police
SUBJECT: Approving the Adoption of the 2025 Seal Beach Local Hazard Mitigation Plan and Authorizing and Directing City Staff to Execute
________________________________________________________________ SUMMARY OF REQUEST:

That the City Council adopt Resolution 7714:

1. Adopting the 2025 Seal Beach Local Hazard Mitigation as presented to the City Council on November 10, 2025, as an official plan; and,

2. Authorizing and directing staff to execute such documents and take such actions as may be necessary and proper to carry out the purposes of this resolution and implement the Local Hazard Mitigation Plan, including applying for grants to fund mitigation actions contained in the plan.

BACKGROUND AND ANALYSIS:

The Federal Hazard Mitigation Grant Program (HMGP) provides funding to State, local, tribal, and territorial (“SLTT”) governments so they can rebuild in a way that reduces or mitigates future natural disaster losses in their communities. The program is authorized by Section 404 of the Federal Stafford Act.

HMGP funding is authorized with a Presidential Major Disaster Declaration. A governor or tribal chief executive may request HMGP funding throughout the state, tribe, or territory when submitting a disaster declaration. The amount of funding made available to the applicant is based on the estimated total federal assistance.

The formula generally gives 15% of the total federal assistance amount provided for recovery from the presidentially declared disaster and is determined by the Federal Emergency Management Association-approved (FEMA) Hazard Mitigation Plan.

The City of Seal Beach recognizes the threat that natural hazards pose to people and property within the community. By undertaking hazard mitigation actions, the City can reduce the potential for harm to residents, businesses, and public infrastructure from future hazard occurrences.

The U.S. Congress passed the Disaster Mitigation Act of 2000 (Disaster Mitigation Act), emphasizing the importance of pre-disaster mitigation and providing hazard mitigation grant opportunities to state and local governments. An adopted Local Hazard Mitigation Plan (LHMP) is required as a condition of eligibility for future funding under multiple FEMA pre- and post-disaster mitigation grant programs.

On November 14, 2024, the Seal Beach City Council approved a professional services agreement with a consulting firm to assist in preparing the City’s Local Hazard Mitigation Plan. The City of Seal Beach fully participated in the FEMAprescribed mitigation planning process to develop the 2024 Local Hazard Mitigation Plan.

The California Governor’s Office of Emergency Services (Cal OES) and the Federal Emergency Management Agency (FEMA) Region IX have reviewed the plan and approved it contingent upon formal adoption by the City Council. Adopting the plan demonstrates the City of Seal Beach’s commitment to protecting the community through proactive hazard mitigation planning and compliance with federal and state requirements.

ENVIRONMENTAL IMPACT:

There is no environmental impact related to this item.

LEGAL ANALYSIS:

The City Attorney has reviewed and approved as to form.

FINANCIAL IMPACT:

Sufficient funding was included in the FY 2025-2026 Budget.

STRATEGIC PLAN:

This item is not applicable to the Strategic Plan.

RECOMMENDATION:

That the City Council adopt Resolution 7714

1. Adopting the 2025 Seal Beach Local Hazard Mitigation as presented to the City Council on November 10, 2025, as an official plan; and,

2. Authorizing and directing staff to execute such documents and take such actions as may be necessary and proper to carry out the purposes of this resolution and implement the Local Hazard Mitigation Plan, including applying for grants to fund mitigation actions contained in the plan.

SUBMITTED BY: NOTED AND APPROVED:

Michael Henderson Patrick Gallegos
Michael Henderson, Chief of Police Patrick Gallegos, City Manager Prepared by: Brian Gray, Emergency Services Coordinator ATTACHMENTS:

A. Resolution 7714
B. 2025 City of Seal Beach Local Hazard Mitigation Plan RESOLUTION 7714

A RESOLUTION OF THE CITY OF SEAL BEACH CITY COUNCIL
AUTHORIZING THE ADOPTION OF THE 2025 SEAL BEACH LOCAL HAZARD

MITIGATION PLAN
WHEREAS, the City of Seal Beach recognizes the threat that natural hazards pose to people and property within our community; and,
WHEREAS, an adopted Local Hazard Mitigation Plan is required as a condition of future funding for mitigation projects under multiple FEMA pre- and post-disaster mitigation grant programs; and,
WHEREAS, on November 12, 2024, the City Council approved Resolution No. 7580, which approved a professional services agreement for consulting services to provide assistance in the drafting of the Local Hazard Mitigation Plan; and, WHEREAS, the City of Seal Beach fully participated in the FEMA-prescribed mitigation planning process to prepare this local hazard mitigation plan; and, WHEREAS, the California Office of Emergency Services and Federal Emergency Management Agency, Region Officials have reviewed the 2025 Seal Beach Local Hazard Mitigation Plan and approved it contingent upon official adoption by the City Council; and,
WHEREAS, adoption by the City Council of Seal Beach demonstrates the jurisdiction’s commitment to fulfilling the mitigation goals and objectives outlined in this Local Hazard Mitigation Plan; and,
WHEREAS, adoption of this legitimizes the plan and authorizes responsible agencies to carry out their responsibilities under the plan.

NOW, THEREFORE, the Seal Beach City Council does hereby resolve, declare, determine, and order as follows:

Section 1. The City of Seal Beach City Council adopts the 2025 Seal Beach Local Hazard Mitigation as presented to the City Council on November 10, 2025 as an official plan
Section 2. City staff are authorized and directed to execute such documents and take such action as may be necessary and proper to carry out the purposes of this resolution and implement the Local Hazard Mitigation Plan, including applying for grants to fund mitigation actions contained in the plan.

PASSED, APPROVED, AND ADOPTED by the Seal Beach City Council at a regular meeting held on the 10th day of November 2025 by the following vote:

AYES: Council Members _____ ____________________________ NOES: Council Members
ABSENT: Council Members
ABSTAIN: Council Members

Lisa Landau, Mayor
ATTEST:

Gloria D. Harper, City Clerk
STATE OF CALIFORNIA }
COUNTY OF ORANGE } SS
CITY OF SEAL BEACH }
I, Gloria D. Harper, City Clerk of the City of Seal Beach, do hereby certify that the foregoing resolution is the original copy of Resolution 7714 on file in the office of the City Clerk, passed, approved, and adopted by the City Council at a regular meeting held on the 10th day of November 2025.

Gloria D. Harper, City Clerk

LOCAL HAZARD MITIGATION PLAN

CITY OF SEAL BEACH

CAL OES REVIEW DRAFT UPDATE
SEPTEMBER 2025
POLlC'E K·9
KEE\' ~V.~'f

Contents Page i
SECTION 1: INTRODUCTION .....................................................................................................1-2

1.1 Plan Purpose............................................................................................................................. 1-3

1.2 Plan Authority.......................................................................................................................... 1-3

1.3 Plan Adoption........................................................................................................................... 1-4

1.4 Plan Organization ................................................................................................................... 1-4

1.5 Mitigation Goals....................................................................................................................... 1-5

1.6 Changes in Hazard Mitigation Priorities ....................................................................... 1-5 SECTION 2: PLANNING PROCESS.............................................................................................2-2

2.1 Organizing Resources ........................................................................................................... 2-2

2.2 Assess Risks ............................................................................................................................2-16

2.3 Develop Mitigation Plan.....................................................................................................2-17 SECTION 3: COMMUNITY PROFILE.........................................................................................3-2

3.1 Physical Setting........................................................................................................................ 3-2

3.2 History......................................................................................................................................... 3-3

3.3 Demographics .......................................................................................................................... 3-5

3.4 Land Use and Existing Development.............................................................................. 3-9

3.5 Development Trends and Future Development ......................................................3-13

3.6 Infrastructure Systems.......................................................................................................3-15

3.7 Socially Vulnerable Populations and Determinations...........................................3-21 SECTION 4: HAZARDS ASSESSMENT.......................................................................................4-2

4.1 Hazard Identification and Prioritization....................................................................... 4-2

4.2 Climate Change Considerations........................................................................................ 4-9

4.3 Vulnerability/Risk Assessment ........................................................................................ 4-9

4.4 Summary of Federally Declared Disasters Affecting the Planning Area........4-11

4.5 Summary of Vulnerability.................................................................................................4-12 SECTION 5: COASTAL AND FLOODING HAZARD ASSESSMENT.....................................5-2

5.1 Flood Hazards .......................................................................................................................... 5-2

5.2 Coastal Storms ......................................................................................................................... 5-9

5.3 Coastal Flood ..........................................................................................................................5-11

5.4 Sea-Level Rise and Coastal Erosion...............................................................................5-13

5.5 Tsunami....................................................................................................................................5-21

5.6 Dam/Reservoir Failure ......................................................................................................5-25 City of Seal Beach Local Hazard Mitigation Plan

TABLE OF CONTENTS
Contents September 2025

5.7 Vulnerability Assessment..................................................................................................5-34

5.8 Socially Vulnerable Populations Assessment ...........................................................5-47 SECTION 6: EXTREME WEATHER HAZARD ASSESSMENT...............................................6-2

6.1 Drought....................................................................................................................................... 6-2

6.2 Extreme Heat............................................................................................................................ 6-8

6.3 Heavy Rains.............................................................................................................................6-12

6.4 Santa Ana Winds and Tornadoes ...................................................................................6-15

6.5 Public Safety Power Shutoff (PSPS)..............................................................................6-19

6.6 Vulnerability Assessment..................................................................................................6-22

6.7 Socially Vulnerable Populations Assessment ...........................................................6-24 SECTION 7: LANDSLIDE HAZARD ASSESSMENT.................................................................7-2

7.1 Landslide.................................................................................................................................... 7-2

7.2 Vulnerability Assessment.................................................................................................... 7-5

7.3 Socially Vulnerable Populations Assessment ............................................................. 7-8 SECTION 8: SEISMIC HAZARD ASSESSMENT........................................................................8-2

8.1 Fault Rupture/Ground Motion.......................................................................................... 8-2

8.2 Liquefaction ............................................................................................................................8-16

8.3 Vulnerability Assessment..................................................................................................8-19

8.4 Socially Vulnerable Populations Assessment ...........................................................8-25 SECTION 9: WILDFIRE AND URBAN FIRE HAZARD ASSESSMENT................................9-2

9.1 Wildfire and Urban Fire....................................................................................................... 9-2

9.2 Wildfire Smoke ........................................................................................................................ 9-7

9.3 Vulnerability Assessment..................................................................................................9-10

9.4 Socially Vulnerable Populations Assessment ...........................................................9-11 SECTION 10: HUMAN-CAUSED HAZARD ASSESSMENT................................................. 10-2

10.1 Hazardous Materials Spill .................................................................................................10-2

10.2 Terrorism/Cyberattacks....................................................................................................10-7

10.3 Civil Disturbance/Civil Unrest.....................................................................................10-10

10.4 Pandemic...............................................................................................................................10-13

10.5 Vulnerability Assessment...............................................................................................10-17

10.6 Socially Vulnerable Populations Assessment ........................................................10-20 SECTION 11: MITIGATION STRATEGY................................................................................ 11-2

11.1 Hazard Mitigation Overview............................................................................................11-2

11.2 Hazard Mitigation Actions ................................................................................................11-8 City of Seal Beach Local Hazard Mitigation Plan
June 2025 Contents
Contents Page iii

11.3 Capabilities Assessment..................................................................................................11-21 SECTION 12: PLAN MAINTENANCE...................................................................................... 12-2

12.1 Purpose of the LHMP and Authority.............................................................................12-2

12.2 Method and Schedule for Updating the Plan within Five Years ........................12-4

12.3 Local Adoption.......................................................................................................................12-5

12.4 Implementation through Existing Programs and Planning Mechanisms......12-5

12.5 2019 LHMP Past Integration Efforts.............................................................................12-7

12.6 Continued Public Involvement........................................................................................12-7

12.7 Point of Contact.....................................................................................................................12-8 SECTION 13: REFERENCES...................................................................................................... 13-2

APPENDIX
Appendix A, City of Seal Beach Adoption Resolution
Appendix B, LHMP Planning Team Documentation
Appendix B.1, LHMP Planning Team Meetings
Appendix B.2, Community Outreach
Appendix B.3, Public Review Documentation
City of Seal Beach Local Hazard Mitigation Plan
Contents September 2025

• Alignment with updated guidance from the 2025 FEMA Local Mitigation Planning Policy Guide, effective April 2025. • Additional considerations included for climate change and socially vulnerable populations (SVPs)
• Review and confirmation of previously identified mitigation goals.

The City of Seal Beach (City) strives to reduce hazards and improve resilience through capital improvement projects, innovative planning, and emergency management practices. The City has developed this 2025 City of Seal Beach Local Hazard Mitigation Plan (LHMP) update in an effort to reduce potential future loss of life and property damage, resulting from natural or human-caused hazards.

Natural and human-caused hazards can cause significant damage to communities, businesses, public infrastructure, and the environment.

The impacts to residents and businesses within communities can be immense, and infrastructure damage can result in regional, economic, and public health consequences. Municipal services and critical infrastructure are vulnerable to a variety of hazards that can result in disruption to operations and services which could include damage to structures, loss of power or other systems, or contamination of natural resources. By planning for natural and human-caused hazards, and implementing projects that mitigate risk, cities can reduce costly damage and improve reliability of service following a disaster incident.

Previously, the City prepared the 2019 LHMP to implement a hazard mitigation strategy within the community. This LHMP expired on August 27, 2024. Thus, this 2025 iteration of the plan serves as a comprehensive hazard mitigation plan update.

No community can be protected against all potential impacts from natural or human-caused hazards. Hazard events often result in periods of emergency response and recovery before returning to “normal” operations. However, communities can reduce potential impacts by taking actions to become more resilient. This LHMP provides a blueprint for the City to reduce threats posed by hazards that may impact people, infrastructure, or operations. Proper planning, prior to a natural or human-caused disaster, will allow the City to return to “normal” sooner, with fewer impacts and disruption to the community.

WHAT'S DIFFERENT ABOUT THE 2025
PLAN?
SECTION 1: INTRODUCTION
The purpose of this LHMP is to provide City staff and City leaders with clear direction for hazard mitigation action planning. This LHMP identifies natural and human-caused hazards that threaten City infrastructure, operations, and people. This LHMP also provides resources, information, and strategies to reduce these risks.

Hazard mitigation plays an important role in reducing disaster impacts by identifying effective and feasible actions to reduce the risks posed by potential hazards before an occurrence. This plan has been developed and updated to be consistent with current standards and regulations, ensuring the understanding of hazards facing the community reflects the best available information and present-day conditions.

The LHMP does not supersede any internal plans or strategies. Rather, the LHMP enhances the ability of the City to identify, inform, and mitigate hazard risks unique to Seal Beach. Information in this LHMP will be used to help guide and coordinate mitigation actions and serve as a tool for City decision-makers to specifically direct mitigation activities and resources.

This LHMP incorporates the latest policy guidance from the Federal Emergency Management Agency (FEMA) Local Mitigation Planning Policy Guide, released April 19, 2022, and effective April 19, 2023. Specifically, this LHMP responds to updated policy guidance relating to climate change, socially vulnerable populations, and equity.

Federal
The federal Robert T. Stafford Disaster Relief and Emergency Act (Stafford Act), as amended by the Disaster Mitigation Act of 2000 (DMA 2000) and supported by various regulations, directs hazard mitigation planning activities, including creation of this plan. The Stafford Act requires State, local, and tribal governmental entities that wish to be eligible for federal hazard mitigation grant funds to submit a hazard mitigation plan, identifying the natural and man-made hazards, risks, and vulnerabilities of each jurisdiction (United States Code [USC] Title 42, Section 5156[a]).

FEMA has promulgated Code of Federal Regulations (CFR) Title 44, Part 201 to carry out the hazard mitigation planning requirements in the Stafford Act. These regulations direct the planning process, plan content, and FEMA approval of hazard mitigation plans. This LHMP complies with the Stafford Act and DMA 2000, along with the appropriate sections of Title 44 of the CFR, including parts 201, 206 and 322.

State
California Government Code Section 8685.9 (Assembly Bill [AB] 2140) limits the State of California’s share of disaster relief funds paid out to local governments to 75 percent of the funds not paid for by federal disaster relief efforts, unless the jurisdiction has adopted a valid hazard mitigation plan consistent with DMA 2000. This LHMP is consistent with current standards and regulations, as outlined by Cal OES. It uses the best available information, and its mitigation actions reflect best practices and community values. This LHMP meets the requirements of current State and federal guidelines and ensures the City of Seal Beach is eligible for all appropriate benefits under State and federal law and practices. This LHMP has been prepared to meet FEMA and Cal City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE

1.1 PLAN PURPOSE

1.2 PLAN AUTHORITY
Section 1. Introduction September 2025
OES requirements, thus making the City eligible for funding and technical assistance from State and federal hazard mitigation programs.

Following FEMA approval of the LHMP, the Seal Beach City Council will formally adopt the LHMP.

Copies of the resolution are provided in Appendix A, City of Seal Beach Adoption Resolution.

The LHMP is organized into seven sections to reflect the logical progression of activities undertaken to develop a hazard mitigation strategy, and includes all relevant documentation required to meet the necessary criteria for FEMA approval. Each section is described briefly below.

Section 1.0: Introduction and Purpose describes the background and purpose of the LHMP, as well as the authority established for its development.

Section 2.0: Planning Process describes the LHMP planning process, as well as the meetings and outreach activities undertaken to engage City officials and staff, stakeholders, and members of the public.

Section 3.0: Community Profile provides the history, geography, demographics, and socioeconomics of the City of Seal Beach, including land use and development trends. This section also evaluates social vulnerability through a variety of environmental justice indices and identifies applicability to the planning area.

Section 4.0: Hazards Assessment provides hazard identification and prioritization, and documents the vulnerability assessment methodology and findings.

Section 5.0: Coastal and Flooding Hazard Assessment identifies and profiles the coastal and flooding hazards affecting the City, including the vulnerability and risk associated with these hazards.

Section 6.0: Extreme Weather Hazard Assessment identifies and profiles the extreme weather hazards affecting the City, including the vulnerability and risk associated with these hazards.

Section 7.0: Landslide Hazard Assessmentidentifies and profiles the landslide hazards affecting the City, including the vulnerability and risk associated with these hazards.

Section 8.0: Seismic Hazard Assessment identifies and profiles the seismic hazards affecting the City, including the vulnerability and risk associated with these hazards.

Section 9.0: Wildfire and Urban Fire Hazard Assessment identifies and profiles the wildfire and urban fire hazards affecting the City, including the vulnerability and risk associated with these hazards.

Section 10.0: Human-Caused Hazard Assessment identifies and profiles the human-caused hazards affecting the City, including the vulnerability and risk associated with these hazards.

Section 11.0: Mitigation Strategy identifies the mitigation strategy and actions to reduce potential risks to the City’s critical facilities, residents, and business owners and assesses the City’s capabilities to implement and achieve the objectives of the mitigation actions.

DW DI !ERA IV City of Seal Beach Local Hazard Mitigation Plan F
{ 1.3 PLAN ADOPTION l:'
• a
i
!
~

1.4 PLAN ORGANIZATION
September 2025 Section 1 . Introduction
Section 12.0: Plan Maintenance and Capabilities discusses implementation of the Plan, including the process to monitor, evaluate, update, and maintain the LHMP, and identifies opportunities for continued public involvement.

Section 13.0: References identifies the various resources utilized throughout the LHMP.

The City has adopted the following goals for reducing disaster risk:
• Reduce the threat to life, injury and property damage for Seal Beach residents, employees and visitors.
• Keep critical services and government functions operational by protecting key infrastructure in Seal Beach.
• Protect natural systems from current and future hazard conditions. • Coordinate mitigation activities among City departments and neighboring jurisdictions. • Strengthen resiliency in Seal Beach through partnerships with community members, local businesses, and community organizations.

The LHMP Planning Team (described below) felt that the overall hazard mitigation goals from the previous plan remained accurate for current planning purposes. These goals are listed above in the previous section. In addition, several hazards previously addressed and profiled are carried over into this update, including wildfire, landslide, flood, climate change, and seismic hazards.

Changes to the LHMP planning process were driven largely by the 2023 FEMA policy update. This LHMP update relied on the input of a cross section of representatives who participated in the LHMP Planning Team, including representatives from internal City departments and external stakeholders (neighboring jurisdictions, nonprofits/NGOs, public safety agencies, and others).

This diverse representation on the LHMP Planning Team produced mitigation actions that consider a variety of perspectives across the planning area.

Similarly, the recent FEMA policy update requires additional consideration for socially vulnerable populations (SVPs) within the planning area. Organizations that represent and serve SVPs were included as part of the LHMP Planning Team (as discussed in Section 2.0) and hazard specific impacts are discussed in Section 4.0 through Section 10.0. Mitigation actions targeted to reducing vulnerability and risk associated with SVPs are included in Section 11.0.

A significant change in this LHMP update includes consideration for human-caused hazards, including pandemic, active shooter, power outage/public safety power shutoff, and trail derailment. All hazards that were previously identified for the City of Seal Beach in the previous plan were carried out through this plan update.

Mitigation actions from the 2019 LHMP are discussed and reviewed in Section 11.0. Mitigation actions from the 2019 LHMP were identified as either completed, in progress or no longer relevant to the LHMP update. New mitigation actions are also highlighted in Section 11.0 and are organized by hazard type.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

1.5 MITIGATION GOALS

1.6 CHANGES IN HAZARD MITIGATION PRIORITIES
Section 1. Introduction September 2025
crrY OF sEAL BEACH
,al.ICE DEPAATlliENT

• Jurisdiction elected to increase the number of considered hazards from the previous plan, from 9 hazards to 20 hazards based on community input.
• Outreach included a wider range of stakeholders, including representatives who serve socially vulnerable populations. • Public outreach efforts were increased through pop-up events, workshops, and engagement during standing City meetings and events.
• Virtual meetings were added to increase engagement.
• The City received over 200 responses to the public survey.

This section describes each stage of the planning process used to develop the LHMP. This LHMP follows a prescribed series of planning steps which includes organizing resources, assessing risk, developing the mitigation strategy, drafting the plan, reviewing/revising the plan, and adopting and submitting the plan for approval. Each step is further described in this section.

Hazard mitigation planning in the United States is guided by statutory regulations described in the Disaster Mitigation Act of 2000 (DMA 2000) and implemented through Title 44 Code of Federal Regulations (CFR) Parts 201 and 206. FEMA hazard mitigation plan guidelines outline a four-step planning process for the development and approval of hazard mitigation plans. Table 2-1, DMA 2000 CFR Crosswalk, lists the specific CFR excerpts that contain the requirements for approval, and identifies the applicable section of this LHMP.

The first step in the planning process involved organization of resources, including identifying the LHMP Project Management Team, convening the LHMP Planning Team, and reviewing
background materials and documents.

WHAT'S DIFFERENT ABOUT THE 2025
PLAN?
SECTION 2: PLANNING PROCESS

2.1 ORGANIZING RESOURCES
Table 2-1
DMA 2000 CFR Crosswalk
DMA 2000 (44 CFR 201.6) 2025 LHMP Plan Section
(1) Organize Resources Section 2
201.6(c)(1) Organize to prepare the plan
201.6(b)(1) Involve the public
201.6(b)(2) and (3) Coordinate with other agencies
(2) Assess Risks Section 4
201.6(c)(2)(i) Assess the hazard
201.6(c)(2)(ii) and (iii) Assess the problem
(3) Develop the Mitigation Plan Section 5
201.6(c)(3)(i) Set goals
201.6(c)(3)(ii) Review possible activities (actions)
201.6(c)(3)(iii) Draft an action plan
(4) Plan Maintenance Section 6
201.6(c)(5) Adopt the plan
201.6(c)(4) Implement, evaluate, and revise
The LHMP Project Management Team was responsible for day-to-day coordination of the LHMP work program, including forming and assembling the LHMP Planning Team; scheduling meetings; preparing, reviewing, and disseminating meeting materials; coordinating, scheduling, and participating in community engagement activities and meetings; and coordinating document review. The LHMP Project Management Team was led by Brian Gray, Emergency Services Coordinator – Sergeant of the City of Seal Beach Police Department.

The LHMP Project Management Team worked with the LHMP Consultant Team throughout the development of the LHMP. The LHMP Consultant Team consisted of hazard mitigation/planning professionals from Michael Baker International. The LHMP Consultant Team provided guidance and support to the City through facilitation of the planning process, data collection, community engagement, and meeting materials and document development.

LHMP Planning Team
The LHMP Project Management Team worked with the LHMP Consultant Team to identify stakeholders to participate in the LHMP. Stakeholders included representatives from internal city departments, along with several external entities including neighboring jurisdictions, utilities, professional organizations, community-based organizations, schools/academia, and other nonprofits/NGOs.

The LHMP Project Management team carefully selected stakeholders to represent a cross section of relevant community lifelines. Community lifelines are defined by FEMA as a fundamental service in the community that, when stabilized, enables all other aspects of society. When disrupted, decisive intervention (e.g., rapid service re-establishment or employment of contingency response solutions) is required. Community lifelines are categorized as follows:

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City of Seal Beach Local Hazard Mitigation Plan ;RA, T DH,BrRAT1V1

2.1.1 LHMP PROJECT MANAGEMENT TEAM
Section 2. Planning Process September 2025
33 Stakeholders
4 Outreach
Events
7 Stakeholder
Meetings
14 Day Public
Comment
Period
200+
Survey Responses
Received
The LHMP public outreach process was
specifically designed to maximize participation
and input from all community members, including
underserved groups and vulnerable populations.

SHI~~~"' 91 I S.111 BHdt BooirlM'lt, SHI Bnclt, CA l)0140 FOR IMMEDIATE REI.EASE
eom.ct. ~ Julia CIHby
(562) 79D-41001x1. 1161
,cil1by@sfflblachel,p
CITY Of SEAL 8u.cH SEEKS C0M"4UNtTY INPUT F~
LOCAi. HAZMO MfTIG.t.TION PLAN UPOAn:

ScAt. BEACH, CA-Thi Cify of Seal 8eedl ii~ QOffil'l'IUnlt; merrlblfl 10 p,aniclpal1 In !tie Updall of !tie LOCII Hl2Md ~ Plan (LHMP) lt'tough. series d in,pofl(ll'I ll(ld vlr1UII ongagcmonl CJR)()t1UnllJC$
• Safety and Security: Law Enforcement/Security, Fire Service, Search and Rescue, Government Service, Community Safety.
• Food, Hydration, Shelter: Food, Hydration, Shelter, Agriculture. • Health and Medical: Medical Care, Public Health, Patient Movement, Medical Supply Chain, Fatality Management.
• Energy: Power Grid, Fuel.
• Communications: Infrastructure, Responder Communications, Alerts, Warnings and Messages, Finance, 911 and Dispatch.
• Transportation: Highway/Roadway/Motor Vehicle, Mass Transit, Railway, Aviation, Maritime.
• Hazardous Materials: Facilities, HAZMAT, Pollutants, Contaminants. • Water Systems: Potable Water Infrastructure, Wastewater Management.

Stakeholders were notified via email, advising them of the City’s efforts to prepare an updated LHMP and requesting their involvement in preparation of the Plan, including an invitation to attend the LHMP Planning Team meetings. The list of stakeholders included in this notification effort is summarized in Table 2-2, LHMP Planning Team and Community Lifelines below.

Table 2-2
LHMP Planning Team and Community Lifelines
Agency or Utility Name Community Lifeline
Local and Regional Agencies Involved in Hazard Mitigation Activities City of Seal Beach Government Service
Orange County Fire Authority Division 1 Government Service; Safety and Security Caltrans Transportation
County of Orange/OCSD OEM Safety and Security; Government Service Los Alamitos Unified School District Government Service; Safety and Security McGaugh Elementary Government Service; Safety and Security Municipal Water District of Orange County Food, Hydration, Shelter; Water Systems Agencies with the Authority to Regulate Development
City of Seal Beach Government Service
Agencies of Neighboring Communities
City of Garden Grove Government Service
City of Los Alamitos Government Service
City of Westminster Government Service
Joint Forces Training Base, Los Alamitos Government Service Seal Beach Naval Weapons Station Government Service
Representatives of Business Academia, and other Private Organizations SoCal Gas Energy
Southern California Edison Energy; Communications
Boeing Safety and Security; Transportation
Optum* Health and Medical
Representatives of Nonprofit Organizations/Community Based Organizations Seal Beach Chamber of Commerce Communications
Leisure World Info Council* Safety and Security; Food, Hydration, Shelter Seal Beach Animal Care Center Food, Hydration, Shelter
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City of Seal Beach Local Hazard Mitigation Plan ;RAT DH,BrRAT1V1 Section 2. Planning Process September 2025
Agency or Utility Name Community Lifeline
Golden Rain Foundation/Leisure World* Safety and Security; Food, Hydration, Shelter Friends of SB National Wildlife Refuge Safety and Security Save Our Beach Safety and Security
*Indicates an LHMP Planning Team member who provides services to socially vulnerable populations or other “high-risk” populations within the planning area. Refer to Section 3.7 for further discussion.

In addition to external stakeholders, the LHMP Planning Team included City of Seal Beach staff members, representing a diverse cross-section of departments and responsibilities. Members of the LHMP Planning Team represented the following City departments and divisions:
• Police
• Community Development
(Planning, building and safety)
• Marine Safety
• Community Services/Recreation
• Fire
• Public Works (Engineering, water,
sewer, maintenance, capital
projects)
• Finance
• City Manager
• City Clerk
The LHMP Planning Team worked together to ensure the success of the planning process and is responsible for its implementation and future maintenance. The committee’s key responsibilities included:
• Participation in LHMP Planning Team meetings
• Collection of valuable local information and other requested data • Decision on plan process and content
• Development and prioritization of mitigation actions for the LHMP • Review and comment on plan drafts
• Coordination and involvement in the public engagement process Table 2-3, LHMP Planning Team, identifies both LHMP Project Management Team and LHMP Planning Team members, along with their roles in plan development.

Table 2-3
LHMP Planning Team
Name Title/Role Organization Planning Team Role
LHMP Project Management Team
Brian Gray
Sergeant Emergency
Services Coordinator
City of Seal
Beach
City Project Manager –
Organization of LHMP
Planning Team and meetings,
development of and
participation in community
outreach, hazard
identification, capabilities
assessment, mitigation
actions and prioritization,
plan coordination and
review.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 2. Planning Process
Name Title/Role Organization Planning Team Role
Alexa Smittle
Community
Development
Director
City of Seal
Beach
Project goals and objectives
identification, hazard
identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion, draft LHMP
review/comment.

LHMP Planning Team
Michael Henderson Chief of Police City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Nick Nicholas Police Captain City of Seal
Beach
Hazard identification and
prioritization
Nicholas Bolin Marine Safety
Lieutenant
City of Seal
Beach
Hazard identification and
prioritization
David Spitz Engineering
City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Iris Lee
Public Works
Director
City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Bill Dorman Building Official City of Seal
Beach
Hazard identification and
prioritization
Reanna Gonzalez Building and Safety City of Seal
Beach
Hazard identification and
prioritization
Kathryn Cho Deputy Director
Public Works
City of Seal
Beach
Hazard identification and
prioritization
Tim Kelsey Recreation Manager
City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Joe Bailey Marine Safety Chief City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
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City of Seal Beach Local Hazard Mitigation Plan ;RA, T DH,BrRAT1V1 Section 2. Planning Process September 2025
Name Title/Role Organization Planning Team Role
Barbara Arenado Finance Director
City of Seal
Beach
Hazard identification and
prioritization
Lisa Landau Mayor, Council
District 3
City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Joe Kalmick City Council District 1 City of Seal
Beach
Hazard identification and
prioritization
Ben Wong City Council District 2
City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Patty Senecal City Council District 4 City of Seal
Beach
Hazard identification and
prioritization
Nathan Steele Mayor Pro Tem,
Council District 5
City of Seal
Beach
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Vicki Hickman
Emergency Planning
Committee (EPC)
Coordinator
Seal Beach
Animal Care
Center
Hazard identification and
prioritization
Marthina Williams Secretary
Leisure World
Info Council
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Nick Massetti Treasurer
Leisure World
Info Council
Hazard identification and
prioritization
Eloy Gomez Health and Safety
Specialist
Leisure World
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Wendy Wood Principal
McGaugh
Elementary
School
Hazard identification and
prioritization
Jerry Friedman
Director, Safety &
Student Services
Los Alamitos
Unified School
District
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 2. Planning Process
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Name Title/Role Organization Planning Team Role
Melissa Mendoza
Community Shift
Supervisor
City of Garden
Grove
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Gabriela Landeros
Emergency
Management
Specialist
MWDOC
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Cathy Winans President
Seal Beach
Animal Care
Center
Hazard identification and
prioritization
Craig Covey Division Chief OCFA Division 1
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Daren DeLeon President
Seal Beach
Chamber of
Commerce
Hazard identification and
prioritization
Anna Burton Emergency Manager
City of
Westminster
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Lance Fuller Emergency Manager
Joint Forces
Training Base
Hazard identification and
prioritization
Blake Perez Public Affairs
Manager
SoCal Gas
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
Tony Cardenas Government
Relations Manager SoCal Edison
Critical facilities review, risk
assessment/ vulnerability
discussion
Tamika Lang Senior Manager Boeing
Hazard identification and
prioritization, critical
facilities review, risk
assessment/ vulnerability
discussion
A series of LHMP Planning Team meetings and smaller focus group meetings were hosted during the LHMP update process. LHMP Planning Team Meeting #1 was hosted during January 2025 to introduce the LHMP, outline the planning process, and discuss priority natural hazards for the D.
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City of Seal Beach Local Hazard Mitigation Plan ;RA, T DH,BrRAT1V1 Section 2. Planning Process September 2025
plan. Stakeholders on the LHMP Planning Team were then invited to participate in focus group meetings, hosted in February – April 2025. Focus groups were either held with a single stakeholder or a group of stakeholders with similar responsibilities or interests. The meeting series was concluded with the LHMP Planning Team Meeting #4, hosted on April 15, 2025. The purpose of the conclusion meeting was to present vulnerability/risk assessment findings and present mitigation actions. The meeting series is summarized below in Table 2-4, LHMP Planning Team and Focus Group Meeting Summary.

Meetings were held both in-person and virtually via Microsoft Teams, to accommodate stakeholders near the city, distributed throughout the region, and remote staff serving on the LHMP Consultant team. Meeting materials, including PowerPoint presentations, sign-in sheets, agendas, notes, and other relevant handouts, are provided in Appendix B, LHMP Planning Team Documentation.

Table 2-4
LHMP Planning Team and Focus Group Meeting Summary
Meeting Date/Time Meeting Title Attendees Meeting Agenda November 19, 2024
4:00 PM – 5:00 PM LHMP Kickoff Meeting LHMP Planning Team (all) • Project Background
• Purpose &
Requirements of
the LHMP
• Project Goals,
Objectives and
Expectations
• Hazard
Identification and
Prioritization
February 12, 2025
2:00 PM – 4:00 PM
LHMP Planning Team
Meeting #1
LHMP Planning Team
(all)
• Critical Facilities
Review
• Risk/Vulnerability
Discussion
• Mitigation Action
Discussion
March 25, 2025
2:00 PM – 4:00 PM
Focus Group Meeting
#1
Internal City Staff
• Critical Facilities
Review
• Risk/Vulnerability
Discussion
• Mitigation Action
Discussion
March 26, 2025
2:00 PM – 3:00 PM
Focus Group Meeting
#2
Neighboring
Jurisdictions, School
District, Public
Utilities and Public
Safety Agencies
• Critical Facilities
Review
• Risk/Vulnerability
Discussion
• Mitigation Action
Discussion
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 2. Planning Process
Meeting Date/Time Meeting Title Attendees Meeting Agenda April 3, 2025
2:00 PM – 4:00 PM
Focus Group Meeting
#3
Attendees Nonprofits
and NGOs
• Critical Facilities
Review
• Risk/Vulnerability
Discussion
• Mitigation Action
Discussion
April 15, 2025
2:00 PM – 3:00 PM
Focus Group Meeting
#4
Remaining
Stakeholders
• Critical Facilities
Review
• Risk/Vulnerability
Discussion
• Mitigation Action
Discussion
June 24, 2025
3:00 PM – 4:00 PM
LHMP Planning Team
Meeting #2
LHMP Planning Team
(all) • Draft LHMP Review
Documentation of this process is included in Appendix B, LHMP Planning Team Documentation.

A public outreach and engagement strategy was developed to maximize public involvement in the LHMP planning process, including underserved groups and vulnerable populations. The LHMP public outreach strategy included a dedicated webpage, a community survey, a community outreach event, and public review draft distribution, as described below; refer to Appendix B, LHMP Planning Team Documentation.

Webpage
A dedicated webpage was developed on the City’s website for the LHMP planning process and advertised through the City’s social media channels. The webpage provided information on the LHMP, and how the public can get involved in the planning process. Contact information was included for comments or questions via email. A link to complete the community survey was posted to encourage participation. The website was updated throughout the planning process and provided notifications and access to LHMP materials. The draft LHMP was also made available for public review on this webpage, available here: https://sealbeachpd.com/local-hazard-mitigationplan/ Virtual outreach on the City’s website posted for the entirety of the LHMP development process allowing for maximum audience reach, including underserved and vulnerable populations.

Traditionally, virtual outreach has the ability to reach community members who may be unable to attend in-person meetings or hearings. Individuals can access all information at their own convenience and have the ability to communicate directly with City staff regarding questions or comments.

City of Seal Beach Local Hazard Mitigation Plan ;RAT DH,BrRAT V

2.1.2 PUBLIC OUTREACH
Section 2. Planning Process September 2025
DEFINITIONS:

Whole Community: engaging the full capacity of private and nonprofit sectors, including businesses, faith-based and disability organizations, and the general public, in conjunction with the participation of local, tribal, state, and Federal governmental partners (FEMA).

Social Vulnerability: characteristics of a person or group that affect their capacity to anticipate, cope with, resist, and recover from the impact of a discrete and identifiable disaster in nature or society.

CITY OF SEAL BEACH

POLICE DEPARTMENT
•
Community Survey
A community survey was developed to obtain input about various hazard mitigation topics. In addition to basic demographic information (e.g., zip code and age), the survey asked participants to identify specific safety concerns, including identifying what hazards they felt were most likely to impact their neighborhood or property. Participants were also asked what actions they had taken to be more resistant to hazards, and preferences for future communication methods from the City. A survey link was posted on the LHMP webpage, City social media outlets, and a QR code was distributed on a printed handout at the community outreach events. Members of the LHMP Planning Team also distributed the survey link to colleagues and constituents within their jurisdiction.

The survey was opened on November 19, 2024, and closed on May 2, 2025. A total of 226 responses were received. Of the 226 participants, approximately 54 percent provided contact information and requested notification when the draft LHMP becomes available for public review.

Survey respondents reported the highest level of concern for seismic related hazards, coastal erosion, terrorism/cyberattacks and drought. Approximately 35 percent of survey respondents reported signing up for emergency alerts and assembling an emergency supply kit. Regarding social vulnerability, more than 80 percent of survey participants identified age (including children under the age of 18 and seniors over the age of 65) as a characteristic that would increase vulnerability in the event of a natural disaster.

Input received was generally similar with feedback from the in-person and stakeholder outreach as outlined below. Survey input directly influenced the final hazard rankings, provided in Section

4.0, Hazard Assessment. Further details received allow the City to better target future outreach and engagement activities regarding the LHMP. The survey specifically provides outreach with underserved and vulnerable populations who may not have the capacity or ability to attend inCity of Seal Beach Local Hazard Mitigation Plan ;RAT DH,BrRAT V @ Take Our Community Survey on Natural Hazards!
City of Seal Beach Local Hazard M1tigat1on Plan
Section 2, Planning Process
The City of Seal Beach is preparing a Local
Hazard Mitigation Plan (LHMP):

The LHMP provides a framework for our community to
reduce vulnerability from natural hazard events ( such
as earthquakes, drought, flood) and man-made hazards
(such as terrorism and cyber attacks).

Take our Community Survey:

Your participation in the planning process is extremely important and vital to the success of the LHMP. To plan for future disasters, we need your feedback!
The survey should take approximately 10 minutes to
complete and is anonymous. Your information will be kept confidential. The results of the survey will be included within the LHMP.

September 2025
person outreach events or hearings. A detailed community outreach summary is included in Appendix B, LHMP Planning Team Documentation.

Environmental Quality Control Board Meeting and Study Session The first community outreach session facilitated for the LHMP was a presentation and study session during a regularly scheduled Environmental Quality Control Board (EQCB) Meeting on Wednesday, February 17th from 6:00 PM to 8:00 PM. In coordination with the City Project Management Team, the LHMP consultant (Michael Baker International) provided an in-depth presentation on the LHMP update. Several topical areas were covered, including the LHMP planning process, hazard identification and prioritization, and social vulnerability characteristic identification. This presentation allowed for questions and answers both from the EQCB and members of the public who attended the hearing. In addition, the hearing was live streamed and posted on the City’s YouTube channel for asynchronous viewing.

Chamber of Commerce Breakfast Presentation
The second community outreach event included a presentation from the City Project Management Team at the Seal Beach Chamber of Commerce General Membership Meeting, on March 13th at 7:30 AM. A ten minute presentation on the LHMP update was included as part of the City Update’s agenda. This update was presented to members of the business community within Seal Beach, many of whom are also local residents. During this meeting, the community survey was promoted as a way to provide input and feedback on the LHMP planning process.

Leisure World Workshop
The third community outreach event
included a workshop held at Leisure World
Clubhouse #4 on Wednesday, March 19th
from 3:00 to 5:00 PM. In coordination with
the City Project Management Team, the
LHMP consultant (Michael Baker
International) provided a presentation on
the LHMP update along with several
interactive opportunities to provide input.

This outreach event included informational
boards illustrating mapped hazard zones,
the opportunity to vote on high priority
hazard reduction, and identify socially
vulnerable populations within the planning
area. Hard copies of the community survey
along with a written comment card were
also provided to workshop attendees.

As Leisure World represents a significant
concentration of socially vulnerable
populations (primarily seniors over the age
of 65 on fixed income, along with disabled
persons) in Seal Beach, priority was given to
scheduling a workshop specifically for this
audience. This location was selected due to
accessibility to seniors within the
community, as Clubhouse #4 is walkable for
Sargent Brian Gray presenting
the LHMP update at Chamber of
Commerce Breakfast
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 2. Planning Process
significant portions of Leisure World. In
addition, Clubhouse #4 is accessible by
Leisure World transit. The City Project
Management Team worked with Leisure
World staff to identify the most popular
day/time to maximize attendance. Overall,
the workshop was attended by
approximately 45 residents from Leisure
World.

Seal Beach Car Show Pop-Up
The final community outreach event was
hosted on Saturday, April 26th from 8:00
AM to 4:00 PM at the Seal Beach Car Show
on Main Street. In coordination with City
staff, the consultant team set up a pop-up
booth near the welcome and registration
tent to receive community input on the
LHMP. Participants had the opportunity to
vote on high priority hazards and review
informational boards on the LHMP update.

Flyers advertising the community survey
along with comment cards were also
provided. Despite a brief period of rain
during the morning, over 60 individuals
stopped by the booth to discuss the LHMP
update.

The pop-up booth was selected as a
method to engage the whole community, with the “come to them” approach. Some segments of the community are less likely to attend formal workshops or hearings, but are interested in easily accessible engagement at public events such as the Seal Beach Car Show. In addition, the central location of the Car Show on Main Street enhanced participation, as many attendees walked or bicycled to the event. Participants at the pop-up booth included those who reside in Seal Beach or frequently visit, and hazard prioritization voting was accessible for participants of all ages.

Public Review Draft LHMP
A draft of the LHMP was made available on the LHMP webpage for the public to review and comment for a two-week period beginning June 18, 2025 to July 16,205. Notification of the draft LHMP availability for review and comment was distributed via the City’s website, social media channels and email listservs. The LHMP received written comments from two individuals.

Members of the Seal Beach Environmental Quality Control Board had the opportunity to ask the City Project Manager questions during a special meeting hosted on July 9, 2025. Documentation of this process is included in Appendix B, LHMP Planning Team Documentation.

The LHMP Planning Team referenced a variety of plans, studies, data, and technical reports available from local, State, and federal sources to prepare the LHMP update. Primary sources were reviewed and incorporated as part of the LHMP planning process, and are listed in Table 2-5, LHMP Pop-Up Booth at the Seal
Beach Car Show.

City of Seal Beach Local Hazard Mitigation Plan ;RAT DH,BrRAT V

2.1.3 REVIEW AND INCORPORATE EXISTING INFORMATION
Section 2. Planning Process September 2025
Existing Plans, Studies, Reports, and Other Technical Data/Information. A complete list of references is included in Section 13.0, References.

Table 2-5
Existing Plans, Studies, Reports, and Other Technical Data/Information Existing Plans, Studies, Reports Planning Process /
Area of Document Inclusion
City of Seal Beach General Plan Multiple Plan Elements
City of Seal Beach Capital Improvement
Plan Multiple Plan Elements
City of Seal Beach Emergency Operations
Plan Multiple Plan Elements
City of Seal Beach Urban Water
Management Plan Hazard Profiles
City of Seal Beach Water Shortage
Contingency Plan Hazard Profiles
City of Seal Beach Cyber Response Plan Hazard Profiles
2018 Orange County Tsunami Annex Hazard Profiles
City of Seal Beach 2021 – 2029 Housing
Element Multiple Plan Elements
Whittier Narrows Dam Safety Modification
EIR Hazard Profiles
City of Seal Beach 2023 Local Coastal
Program (Draft Form) Multiple Plan Elements
Main Street Specific Plan Multiple Plan Elements
2025 Irvine Ranch Water District Dam
Safety Program Hazard Profiles
In accordance with FEMA requirements, the LHMP Planning Team identified and prioritized the hazards affecting the City and assessed vulnerability from those hazards. Results from this phase of the LHMP planning process aided subsequent identification of appropriate mitigation actions to reduce risk from these hazards; refer to Section 11.0, Mitigation Strategy.

Based on a review of past hazards, as well as a review of existing plans, reports, and other technical studies, data, and information, the LHMP Planning Team determined which specific hazards could affect the City. Content for each hazard profile is provided in Section 4.0 through Section 10.0.

Hazard profiling exposes the unique characteristics of individual hazards and begins the process of determining which areas within the City are vulnerable to specific hazards. The vulnerability assessment included input from the LHMP Planning Team and a GIS overlaying method to map hazard risk assessments. Using these methodologies, critical facilities impacted by hazards were identified and potential loss estimates were determined, where available. Detailed information on the vulnerability assessments for each hazard is provided in Section 4.0 through Section 10.0.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

2.2 ASSESS RISKS

2.2.1 IDENTIFY /PROFILE HAZARDS

2.2.2 ASSESS VULNERABILITIES
September 2025 Section 2. Planning Process
The LHMP Planning Team reviewed mitigation goals from the previous 2019 LHMP and made minor editorial changes for clarification. Hazard mitigation goals were discussed during Meeting #1, before finalization and incorporation into the LHMP. The Mitigation Goals are included in Section 1.0, Introduction.

A capabilities assessment is a comprehensive review of all mitigation capabilities and tools currently available to the City for mitigation action implementation, prescribed in the LHMP. The LHMP Planning Team identified the planning and regulatory; administrative and technical; financial; and education and outreach capabilities to implement mitigation actions, as detailed in Section 11.0, Mitigation Strategy.

As part of the LHMP planning process, the LHMP Planning Team worked to identify and develop mitigation actions, after which mitigation actions were prioritized as high, medium, or low. A detailed discussion of the identification and prioritization of mitigation actions, and the creation of the implementation strategy is provided in Section 11.0, Mitigation Strategy.

This plan will be submitted to Cal OES and FEMA for review. Upon receiving “approvable pending adoption” notification from FEMA, this plan will be presented for consideration and approval by the Seal Beach City Council. If approved, a copy of the resolution will be provided in Appendix A, City of Seal Beach LHMP Adoption Resolution.

Plan maintenance procedures, found in Section 12.0, Plan Maintenance, include the measures the City will take to ensure the LHMP’s continuous long-term implementation. The procedures also include the manner in which the LHMP will be regularly monitored, reported upon, evaluated, and updated to remain a current and meaningful planning document.

City of Seal Beach Local Hazard Mitigation Plan ;RAT DH,BrRAT V

2.3 DEVELOP MITIGATION PLAN

2.3.1 IDENTIFY GOALS

2.3.2 DEVELOP CAPABILITIES ASSESSMENT

2.3.3 IDENTIFY MITIGATION ACTIONS

2.3.4 PLAN ADOPTION AND SUBMITTAL

2.3.5 PLAN MAINTENANCE
Section 2. Planning Process September 2025
Seal Beach Police Facility Dog Yosa in attendance at the LHMP Planning Team Meeting #1. From Canine Companions®, Yosa assists her handler, Captain Nick Nicholas, during his work with victims, witnesses, and community members exposed to traumatic events.

• The City experienced a slight increase in population since the previous LHMP.
• The number of identified critical facilities has increased. • Socially Vulnerable Populations (SVPs) have been identified, composed of the following groups:
o Persons aged 65 or older
o Persons under the age of 17
o Persons with a disability
o Unemployed individuals
o Persons experiencing a high pollution burden
o Tourists, visitors, and special event attendees.

The City of Seal Beach is located along the most northwestern point of Orange County, adjacent to the Pacific Ocean. The City covers approximately 11.51 square miles of land area and 1.72 square miles of water area for a total of 13.23 square miles. A significant portion of Seal Beach is occupied by Naval Weapons Station Seal Beach, a military base. The City of Seal Beach is bordered by the City of Long Beach and the Alamitos Bay to the northwest, the City of Los Alamitos and censusdesignated community Rossmoor to the north, the City of Huntington Beach to the southeast, and the Cities of Westminster and Garden Grove to the east. The City is relatively flat and sits at an elevation of 15 feet above sea level.

WHAT'S DIFFERENT ABOUT THE 2025
PLAN?
SECTION 3: COMMUNITY PROFILE

3.1 PHYSICAL SETTING
The Gabrielino-Tongva (Tongva) people, who were known for their skills in basket weaving, fishing and hunting, have inhabited the Los Angeles Basin for thousands of years. Tongva villages were located around the Los Angeles River, San Gabriel River, Santa Ana River, and other coastal areas. One such village was located in present-day Seal Beach called Motuucheyngna, which was part of a larger ceremonial and trading center.1,2 The Tongva people defined their world as Tovaangar, which is also the origin for the name of the people. This tribe also became known as “Gabrielino”, or sometimes called “Gabrieleño”, associated with the San Gabriel Mission where many tribe members were taken.

The first permanent European presence in Orange County was the 1776 establishment of Mission San Juan Capistrano to the south. After Mexico (including California before the Treaty of Guadalupe Hidalgo) became independent from Spain in 1821, the missions were secularized while large portions of land were granted to prominent figures. The area of modern-day Seal Beach became part of the Rancho Los Alamitos grant given to Spanish soldier Manuel Nieto.3 After Mexico’s cessation of California to the United States in 1884, an area east of modern-day Seal Beach became home to a group of German immigrants who established “Anaheim.” This group established a port called Anaheim Landing near where the Naval Weapons Station is today. The port grew and developed into what is now the downtown area of Seal Beach. In the early 1900s, the settlement eventually shifted from being a shipping center to a resort town and cemented this transition by changing its name to Bay City in 1903. Connections to Los Angeles via the burgeoning Pacific Electric rail system allowed visitors easy access to Bay City. The City subsequently adopted the name Seal Beach when it became an officially incorporated city in 1915.4 The advent of the Second World War prompted the next cycle of the City of Seal Beach’s growth. It was during this time that the Naval Weapons Station was built, and the aerospace industry took root in the city.

The Leisure World community was also established during the late 1960s, an innovative senior living facility that was the largest development of its kind. Today, the Seal Beach is still a tourist destination and boasts a population of more than 24,000 residents.5 6 1 Tongva People, Villages, https://www.tongvapeople.org/?page_id=696, accessed January 8, 2025. 2 Tongva People: A dynamic study of the Villages and Locations of the Gabrielino-Tongva Indians, “Introduction”, https://www.tongvapeople.org/, accessed June 13, 2022. 3 Orange County Historical Society, A Brief History of Orange County, https://www.orangecountyhistory.org/wp/?page_id=38, accessed January 10, 2025. 4 City of Seal Beach, About Seal Beach, https://www.sealbeachca.gov/About-Seal-Beach, accessed January 10, 2025.
5 United States Census Bureau, Seal Beach Quick Facts,
https://www.census.gov/quickfacts/fact/table/sealbeachcitycalifornia/PST045223, accessed January 10, 2025.
6 City of Seal Beach General Plan, Land Use Element,
https://www.sealbeachca.gov/Portals/0/Documents/Land%20Use%20Element.pdf, adopted 2003, accessed January 8, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE

3.2 HISTORY
Section 3. Community Profile September 2025
Social vulnerability is defined as characteristics
of a person or group that affect their capacity
to anticipate, cope with, resist, and recover
from the impact of a discrete and identifiable
disaster in nature or society.
24,868
City Population

61.2 Median Age

1.90 Average
Household Size
People with
Disabilities
Elderly
Persons
Unemployed
Persons
People Facing
High Levels of
Pollution
Socially Vulnerable Populations
in Seal Beach Include:

Basic demographic and socioeconomic data for the City of Seal Beach (population, education, employment, and housing) obtained from the U.S. Census 2023 American Community Survey (ACS) has been summarized in the sections below.7
Table 3-1, City of Seal Beach and Orange County Population and Housing Data (2023), provides an overview of the City’s and County’s demographics.

Table 3-1
City of Seal Beach and Orange County Population and Housing Data (2023) Category City of Seal Beach Orange County
Total Population 24,868 3,164,063
Percent of Residents that are
children (under 18 years)

13.1% 21.3%
Percent of Residents that are
senior citizens (65 and over)*

43.7% 15.8%
Median Age (years) 61.2 39.1
Median Household Income $83,045 $113,702
Median House Value (Owneroccupied housing units w/ a
mortgage)
$1,192,500 $938,700
Occupied Housing Units 13,369 1,074,105
Percent of Renter-Occupied
Housing Units

24.1% 43.6%
Percent of Owner-Occupied
Housing Units

75.9% 56.4%
Average Household Size 1.90 3.47
Seal Beach is home to Leisure World, a gated 55+ age-restricted community, which accounts for approximately 36 percent of the City’s total population. The presence of this development impacts the socioeconomic profile of the City, as discussed in the following sections.

Source: US Census Bureau, 2023 American Community Survey 5-Year Estimates, https://data.census.gov/profile/Seal_Beach_city,_California?g=160XX00US0670686, accessed April 9, 2025.

The City of Seal Beach has an estimated population of 24,868 people according to 2023 American Community Survey 5-year estimates. In terms of age demographics, residents under the age of 18 make up 13.1 percent of the City’s population, which is less than that of Orange County at 21.3 percent. The median age of City residents is 61.2 years of age. Comparatively, the median age of Orange County residents is 39.1 years of age. The population of senior citizens in the City is approximately 43.7 percent, which is approximately 27.9 percent higher than the 15.8 percent of senior citizens in Orange County. Overall, these metrics show that Seal Beach has a comparatively older population than that of the County, which can be attributed, at least in part, to the agerestricted Leisure World community of over 9,000 residents Seal Beach has a lower median household income, yet a higher median home ownership rate compared to Orange County as a whole. Median household income in the City is $83,045, which is 7 The 2023 American Community Survey (ACS) 5-year estimates is the most current 5-year data profile available. It represents 60 months of collected data and provides the most reliable and largest data set.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE

3.3 DEMOGRAPHICS

3.3. l POPULATION
Section 3. Community Profile September 2025
lower than the Orange County median income of $113,702. Owner-occupied housing units in the City accounts for 75.9 percent of total occupied housing, which is higher than the 56.4 percent of owner-occupied housing units in the County. The median home value in the City is $1,192,500 compared to a median Orange County home value of $938,700. The City also has a lower average household size at 1.9 compared to the County’s average household size of 3.47.8 Table 3-2, City of Seal Beach and Orange County Racial and Ethnic Composition (2023), provides an overview of the City’s and County’s racial/ethnic demographics.

Table 3-2
City of Seal Beach and Orange County Racial and Ethnic Composition (2023) Race or Ethnicity City of Seal Beach Orange County
Population Percentage of
Population Population Percentage of Population
White 19,953 80.2% 1,911,509 60.4%
Black or African American 506 2.0% 84,846 2.7%
American Indian and Alaskan
Native
459 1.8% 62,657 2.0%
Asian 4,048 16.3% 791,027 25.0%
Native Hawaiian and Other
Pacific Islander
82 0.3% 23,135 0.7%
Other Race 2,287 9.2% 789,922 25.0%
Two or More Races 2,249 9.0% 129,850 4.1%
Hispanic or Latino (of any
race)1
3,071 12.3% 1,080,480 34.1%
Total 24,868 N/A* 3,164,063 N/A*
1 Hispanic or Latino persons are not counted as a separate racial or ethnic category; persons who identify as Hispanic or Latino are also included in other racial or ethnic categories. Totals may vary slightly due to rounding.
*Percentages do not equal 100% as some individuals identified as more than one race.

Source: US Census Bureau, 2023: American Community Survey 5-Year Estimates, DP05 Demographic and Housing Estimate, https://data.census.gov/profile/Seal_Beach_city,_California?g=160XX00US0670686, accessed April 9, 2025.

The majority racial/ethnic population in Seal Beach is white at 80.2 percent of residents. In contrast, the white population of Orange County accounts for 60.4 percent. The Asian population of the City constitutes 16.3 percent, which is lower than the 25.0 percent Asian population of the County. Hispanic or Latino persons of any race constitute 12.3 percent of the City’s residents in comparison to 34.1 percent of County residents. Percentages of Black or African American is about

2.0 percent, slightly lower than Orange County at 2.7 percent. Similarly, the City’s American Indian and Alaskan Native population at 1.8 percent is slightly lower compared to the County’s at 2.0 percent. The City of Seal Beach also has a lower Native Hawaiian and Other Pacific Islander population at 0.3 percent compared to the County’s 0.7 percent.

Persons identifying as “other race” account for 9.2 percent of the City’s population, while those reporting two or more races make up 9.0 percent of the City’s population. Percentages of “other 8 American 2023 American Community Survey 5-Year Estimates, S1101 Households and Families, https://data.census.gov/table/ACSST5Y2023.S1101?q=S1101:%20Households%20and%20Families&g=05 0XX00US06059_160XX00US0670686, accessed January 8, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
race” and two or more races of Orange County are 25.0 percent and 4.1 percent, respectively. The overall racial/ethnic composition of the City is generally less diverse that of the Orange County.

Educational attainment is analyzed based upon the population of individuals aged 25 and over.

Residents in the City of Seal Beach have a higher level of educational attainment compared to Orange County; refer to Table 3-3, City of Seal Beach and Orange County Educational Attainment (2023).

Table 3-3
City of Seal Beach and Orange County Educational Attainment (2023) Educational Attainment
(Age 25 and Over)
City of Seal Beach Orange County
Population Percentage of
Population Population Percentage of Population
Less than 9th Grade 389 1.9% 160,449 7.3%
9th to 12th Grade, No Diploma 559 2.7% 127,451 5.8%
High School Graduate 3,173 15.3% 379,386 17.2%
Some College, No Degree 4,017 19.4% 411,837 18.7%
Associate Degree 1,980 9.6% 168,956 7.7%
Bachelor’s Degree 5,986 28.9% 601,466 27.3%
Graduate or Professional
Degree
4,587 22.2% 355,582 16.1%
Total* 20,691 100.0% 2,205,127 100.0%
*Totals may vary slightly due to rounding.

Source: US Census Bureau, 2023: American Community Survey 5-Year Estimates, S1501 Educational Attainment. https://data.census.gov/profile/Seal_Beach_city,_California?g=160XX00US0670686, accessed April 9, 2025.

Of the City’s population aged 25 years and older, 22.2 percent attained a graduate or professional degree, 28.9 percent attained a bachelor’s degree, and 9.6 percent attained an associate degree.

Thus, about 60.7 percent of the City’s population has completed a higher education degree. In comparison, the County’s higher education degree attainment is as follows: 16.1 percent attained a graduate or professional degree, 27.3 percent attained a bachelor’s degree, and 7.7 percent attained an associate degree. Approximately 4.6 percent of adults in the City of Seal Beach have not completed high school compared to approximately 13.1 percent of adults in the County.

According to the 2023 American Community Survey 5- Year Estimate, there are 22,077 residents over 16 years of age in the City of Seal Beach, and 9,873 were in the labor force.9 Out of the 9,873 people in the labor force, 9,204 (41.7 percent) were employed and 485 (2.2 percent) were unemployed.

The educational services and health care/social services sector employed the largest number of City residents (26.6 percent), followed by professional, scientific, and management, and administrative and waste management services (12.3 percent); finance and insurance, and real 9 2023 American Community Survey 5-Year Estimates, DP03 Selected Economic Characteristics, https://data.census.gov/table/ACSDP5Y2023.DP03?q=DP03%20Selected%20Economic%20Characteristic s%20san%20bernardino%20county&g=050XX00US06059_160XX00US0670686, accessed January 8, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE

3.3.2 EDUCATIONAL ATTAINMENT

3.3.3 EMPLOYMENT
Section 3. Community Profile September 2025
estate and rental and leasing (10.4 percent); manufacturing (9.5 percent); retail trade (8.8 percent); and other services. The median household income in the City was $83,045.

While approximately 23.6 percent of employees work from home, a majority of Seal Beach residents commute for work. The average commute travel time is 30 minutes.10 According to the US Census Bureau 2023 American Survey 5-Year Estimates, there are housing units within the City, 88.6 percent of which are occupied.11 The most prevalent type of housing with the City of Seal Beach is multifamily units at 48.2 percent.12 This is followed by single-family detached (32.6 percent), single-family attached (10.4 percent), multifamily, 2-4 units (7.7 percent), and mobile homes (1.1 percent).13
The City of Seal Beach has had continuous structure-built growth as shown in Table 3-4, Years Structure Built Growth. The majority of housing units were built within the last 70 years, with the majority of development occurring between 1960 to 1979. . 14 The United States Census Bureau
estimates an average household size of 1.90 persons per household in the City.15 Table 3-4
Years Structure Built Growth
Year Structure Built Percentage
Built 2020 or later 0.8%
Built 2010 to 2019 7.9%
Built 2000 to 2009 8.4%
Built 1990 to 1999 10.9%
Built 1980 to 1989 14.6%
Built 1970 to 1979 22.4%
Built 1960 to 1969 18.0%
Built 1950 to 1959 12.5%
Built 1940 to 1949 1.9%
Built 1939 or earlier 2.5%
Source: 2023 American Community Survey 5-Year Estimates, DP04 Selected Housing Characteristics, https://data.census.gov/table/ACSDP5Y2023.DP04?q=DP04%20Selected%20Housing%20Characteristi cs%20&g=050XX00US06059_160XX00US,0670686, accessed June 10, 2025. 10 Ibid.
11 2023 American Community Survey 5-Year Estimates, DP04 Selected Housing Characteristics, https://data.census.gov/table/ACSDP5Y2023.DP04?q=DP04%20Selected%20Housing%20Characteristics %20&g=050XX00US06059_160XX00US0670686, accessed January 8, 2025. 12 City of Seal Beach, 2021 - 2029 Housing Element,
https://www.sealbeachca.gov/Portals/0/Documents/6th%20Seal%20Beach%20Housing%20Element_Ad opted-compressed.pdf?ver=2022-02-10-091549-117, adopted February 7, 2022, accessed January 8, 2025. 13 Ibid.
14 2023 American Community Survey 5-Year Estimates, DP04 Selected Housing Characteristics, https://data.census.gov/table/ACSDP5Y2023.DP04?q=DP04%20Selected%20Housing%20Characteristics %20&g=050XX00US06059_160XX00US,0670686, accessed January 8, 2025. 2023 American Community Survey 5-Year Estimates, DP04 Selected Housing Characteristics, https://data.census.gov/table/ACSDP5Y2023.DP04?q=DP04%20Selected%20Housing%20Characteristics %20&g=050XX00US06059_160XX00US,0670686, accessed
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September 2025
City of Seal Beach Local Hazard Mitigation Plan
Section 3. Community Profile
The Seal Beach General Plan guides the development of the City. The City of Seal Beach General Plan assigns land use designations to all land located within its incorporated boundaries; refer to Figure 3-1, Seal Beach Zoning Map and Figure 3-2, Seal Beach Land Use Map. Table 3-5, Seal Beach Land Use Summary and Table 3-6, Seal Beach Land Use Intensity/Density Standards identifies the current General Plan land use designations and descriptions of the typical uses allowed in each designation.

The primary land uses within the City are military at 60.8 percent, followed by open space at 17.1 percent, residential at 14.4 percent, industrial at 2.4 percent, and commercial at 2.2.

The Seal Beach Naval Weapons Station is the eastern portion of the city, bordering the both Westminster and Huntington Beach. Included as part of this military installation is the Seal Beach National Wildlife Refuge – in addition to the Los Cerritos Wetlands, these areas constitute significant open space within Seal Beach. Residential land use is distributed throughout Seal Beach, including a variety of housing types from low, medium and high densities. Light industrial uses are primarily concentrated within the Boeing Specific Plan area and adjacent parcels near the intersection of Westminster Boulevard and Seal Beach Boulevard. Commercial hubs are distributed throughout the City, include Main Street/Pacific Coast Highway in the Old Town Neighborhood and Old Ranch Town Center/Shops at Rossmoor along Seal Beach Boulevard.

Table 3-5
Seal Beach Land Use Summary
Designation
Proposed/
Developed
(acres)
Undeveloped
(acres)
Total
Acres Description
Residential
Low (LDR) 353.7 0.0 353.7 Minimum lot area of 5,000
square feet per dwelling unit
Medium
(MDR)
505.4 0.0 505.4 Minimum lot area of 2,500
square feet per dwelling unit;
minimum lot area of 2,500
square feet per dwelling unit in
Planning Area 1 south of Pacific
Coast Highway
High (HDR) 166.4 0.0 166.4 Minimum lot area of 1350
square feet per dwelling unit,
Minimum lot area of 2178
square feet per dwelling unit in
Planning Area 1 South of Pacific
Coast Highway and Marina
Drive, Minimum lot area of 960
square feet per dwelling unit in
Planning Area 4, consisting of
Rossmoor Business Center
Commercial
Professional
Office (PO)

16.4 0.0 16.4 Professional and medical offices
of all types, architects,
engineers, real estate and
insurance offices, banks,
City of Seal Beach Local Hazard Mitigation Plan DRi\1 ;[,IBERA, IVE

3.4 LAND USE AND EXISTING DEVELOPMENT
Section 3. Community Profile September 2025
Designation
Proposed/
Developed
(acres)
Undeveloped
(acres)
Total
Acres Description
savings and loan
establishments and other types
of financial activities.

Service (SC) 49.3 0.0 49.3 Consists of commercial
establishments selling a broad
range of convenience and
consumer good or providing a
variety of personal services.

Structures involved would
usually be two main types 1)
those located along streets with
heavy pedestrian traffic along
sidewalks with stores usually
cost to right way of way lines,
2) establishment which
customers travel by automobile
and where stores may be set
back from the road, possibly in
a unified development, to
provide parking
General (GC) 75.4 18.0 93.4 Primarily highway-oriented
commercial use for automobile
service stations, automobile
sales, automobile repair, motels
and hotels, restaurants and
other related uses.

Industrial
Light (LI) 67.0 50.0 117.0 Boeing Integrated Defense
Systems Headquarters facility
at the intersection of Seal Beach
Boulevard and Westminster
Avenue
Oil Extraction
(OE)

54.6 0.0 54.6 Oil separation facility that
separated oil and seawater
pumped to the on-shore
facilities from an offshore oil
island that has recently been
decommissioned and
dismantled.

Open Space
Open Space
(OS)

0.0 42.7 42.7 Nature trails, environmental
educational purposes,
beachfront,
Golf Course
(GC)
156.8 0.0 156.8 Private Old Ranch Golf Course
with a public golf driving range
Wetlands &
Wildlife
Refuge
(WWR)
100.0 920.0 1,020.0 Los Cerritos Wetland along
Pacific Coast Highway and Seal
Beach National Wildlife Refuge
Park (P) 65.4 19.0 65.4 Parks and recreational spaces
including Gum Grove Nature
Park, Sunset Marina Park,
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
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Designation
Proposed/
Developed
(acres)
Undeveloped
(acres)
Total
Acres Description
Eisenhower Park, Arbor Park,
Bluebell Park, Zoeter Field
School (S) 15.3 0.0 15.3 One school in the City: McGaugh Elementary School. Due to very
limited population growth
proposed by the Land Use
Element, no additional schools
are proposed or needed for the
community.

Community
Facility (CF)

61.8 0.0 61.8 Includes public community
facilities for residents and
tourists.

Military 4,336.0* 0.0 4,336.0* Located on the eastern
boundary of the Seal Beach
community
Beach (B) 0.0 80.3 80.3 Includes recreational areas, and beach areas.

Total 6,023.5 1,111.0 7,134.5
Source: City of Seal Beach General Plan, Land Use Element Land Use Tables, https://www.sealbeachca.gov/Portals/0/Documents/Land%20Use%20Tables.pdf, adopted February 28, 2011, accessed January 8, 2025.

Table 3-6
Seal Beach Land Use Intensity/Density Standards
Land Use
Designation
Minimum
Lot Area
Building Intensity
Dwelling Units
per Acre
(DU/Acre)*
Density
(Persons/acre)**
Residential
Low-Density
Residential
5,000 sq. ft. 9.0 DU/Acre 16.5
Medium-Density
Residential
2,500 sq. ft. 17.0 DU/Acre 31.0
High-Density
Residential
Planning Area 1 2,178 sq. ft. 20.0 DU/Acre 36.6
Planning Area 2,3 1,350 sq. ft. 32.2 DU/Acre 58.9
Planning Area 4 960 sq. ft. 45.3 DU/Acre 82.8
Commercial
Professional Office 7,000 sq. ft. 0.50-0.60 FAR 1 Employee/300 sq. ft.

Service Commercial 7,000 sq. ft. 0.60-0.75 FAR 1 Employee/333 sq. ft.

General Commercial 7,000 sq. ft. 0.60-0.80 FAR 1 Employee/450 sq. ft.

Industrial
Light Industrial 10,000 sq. ft. 0.70 FAR 1 Employee/470 sq. ft.

Source: City of Seal Beach General Plan, Land Use Element Land Use Tables, https://www.sealbeachca.gov/Portals/0/Documents/Land%20Use%20Tables.pdf, adopted February 28, 2011, accessed January 8, 2025.
* The development intensity standard indicates the theoretical “maximum” allowable development permitted for each specific land use designation (DU=dwelling units; FAR=floor area ratio). All proposed development must also adhere to the City’s zoning code and/or regulations established in a specific plan. ** U.S. 2000Census Data-(City of Seal Beach averages 1.83 persons per household) City of Seal Beach Local Hazard Mitigation Plan DRi\1 ;[,IBERA, IVE I
Section 3. Community Profile September 2025
Figure 3-1
Seal Beach Zoning Map
Figure 3-2
Seal Beach Land Use Map
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CITY OF SEAL BEACH

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Section 3. Community Profile
The City is also in the process of developing its Local Coastal Program, which consist of planning documents used by local governments to guide development in the coastal zone, in partnership with the Coastal Commission. LCPs contain rules and regulations for future development and protection of coastal resources, by specifying appropriate location, type, and scale of new or changed uses. LCPs must be in compliance with the broad requirements of the California Coastal Act and reflect the unique and specific community characteristics of the jurisdiction. Each LCP consists of a Land Use Plan (LUP) and Local Implementation Plan (LIP). The LUP designates land use classifications, and goals/policies guiding development (similar in nature to a City’s General Plan, but specifically for the coastal zone). The LIP includes measures to implement the LUP, typically through the zoning ordinance. In May 2023, the City of Seal Beach submitted a revised Draft Land Use Plan to the Coastal Commission for their comment and feedback.

Since the previous iteration of the 2019 LHMP, population patterns have remained the same, while development and land use in the planning area has not substantially changed. The City population increased nominally, from approximately 24,510 individuals in the 2019 LHMP to 24,868 in this current LHMP – representing a gain of 358 individuals or 1.46 percent increase of the City population.16 ,17 As minor and small-scale changes in land use occurred while the previous 2019 LHMP was active, risk and vulnerability associated with the majority of hazards listed in the LHMP nominally increased. Any differences related to specific hazards are further discussed within the hazard profiles in Section 4.0.

For future land use, development trends and population patterns, the City of Seal Beach General Plan is a key guide. Most recently, future growth is also projected in the 2021 – 2029 Housing Element. A key indicator of projected growth is the California Department of Housing and Community Development (HCD) Regional Housing Need Allocation (RHNA). The RHNA represents the minimum number of housing units the City is required to provide “adequate sites” for zoning and is one of the primary threshold criteria to achieve State approval of the Housing Element. It is noted that the RHNA represents a planning target for new residential growth and is not a building quota.

As required by the RHNA determination, the City is required to account for the growth of an additional 1,243 housing units at varying income levels. The RHNA allocation for 2021 – 2029 for the City as follows in Table 3-7, City of Seal Beach RHNA Allocation:

Table 3-7
City of Seal Beach RHNA Allocation
Income Level Percent of AMI* Units Percent
Very Low** Up to - 50% 258 20.8
January 8, 2025.
ach, Local Hazard Mitigation Plan,
https://www.sealbeachca.gov/Portals/0/Documents/Seal%20Beach%20HMP20181018_Public%20Review_wAppendices.pdf, adopted 2019, accessed January 14, 2025. 17 NCHstats, California Population 2024 – 5 Regions with the Largest Increases, https://nchstats.com/california-population-growth/, updated January 2, 2025, accessed January 9, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE

3.5 DEVELOPMENT TRENDS AND FUTURE DEVELOPMENT
Section 3. Community Profile September 2025
Income Level Percent of AMI* Units Percent
Low 51 - 80% 201 16.2
Moderate 81 - 120% 239 19.2
Above Moderate 120%+ 545 43.8
Total 1,243 100%
*AMI – Area Median Income
**Includes the extremely low-income category, which is estimated as half the VL need pursuant to Government Code Sec. 65583(a)(1)
Source: City of Seal Beach, 2021
The City is required to demonstrate an availability of land, zoning provisions, and development standards that facilitate and encourage affordable housing development. The majority of sites that are identified for potential housing development as part of the 2021 – 2029 Housing Element include Accurate Storage, Shops at Rossmoor, Old Ranch Town Center, Old Ranch Country Club, Leisure World, Seal Beach Plaza, Seal Beach Center, Main Street Specific Plan Area, and 99 Marina.18 While it is unknown how much of the residential growth associated with the Housing Element Update will be approved or constructed within the five-year period of this LHMP, it is reasonable to assume that some level of residential development will occur. Any residential growth in the planning area is generally associated with population growth. Discussions on how projected growth could impact risk and vulnerability is discussed on a hazard-by-hazard basis within Section 4.0.

In addition to the RHNA requirements, the City of Seal Beach Public Works is overseeing the design and construction of various capital improvement projects. See Table 3-8, Major Capital Improvement Projects, for a description and status of current and future development projects.

Table 3-8
Major Capital Improvement Projects
Project Description
Beach and Pier • Life Guard/Police Department Substation • 8th/10th Street Lot and ADA Ramps
• Tidelands Facility Security System Update
• Pier Concrete Abutment Structural Testing/Phase 2 Rehabilitation Building and
Facilities
• Tennis Center Improvement Project
• Revitalization Plan
• North Seal Beach Community Center
• North Seal Beach Community Center Phase 2
• Building Improvement Program
• Council Chambers Improvements
• Annual Playground Resurfacing Program
18 City of Seal Beach, Housing Element 2021 – 2029,
https://www.sealbeachca.gov/Portals/0/Documents/6th%20Seal%20Beach%20Housing%20Element_Ad opted-compressed.pdf?ver=2022-02-10-091549-117, accessed January 13, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
Project Description
• Citywide ADA Improvements
• SBTPC Court Resurfacing (All Courts) and LED Lighting Upgrades Sewer • Sewer Mainline Improvement Program
• Pump Station 35 Upgrades
Storm Drain • San Gabriel River Trash Mitigation Initiative • 2024 Environmental Clean Up – Galleon Way – Grant Match • Storm Drain Cleaning
Street and
Transportation
• Lampson Bike Trail Gap Closure Project
• Main Street Improvements Program
• Seal Beach Blvd Traffic Signal Synchronization
• Annual Slurry Seal Program
• Annual Local Paving Program
• Arterial Street Resurfacing Program
• Annual ADA Improvements – Public R/W
• Annual Striping Program
• Citywide Traffic Signal Improvement Program
• OCTA 405 Widening Co-Op Project
• Seal Beach Blvd at North Gate Road Improvements
• Alley Repair
Water • Beverly Manor Water Pump Station Rehabilitation • SCADA Improvement Upgrade Project
• Lampson Well Head Treatment
• LCWA Watermain Lining
• I-405 Improvement Project Waterline Relocation
Source: City of Seal Beach, Adopted Operating & Capital Improvement Budget Fiscal Year 2025-2026, https://www.sealbeachca.gov/Portals/0/Documents/City%20Manager/Proposed%20Budget%20FY%2025-26.pdf?ver=2025- 05-02-182639-930&timestamp=1746235780157, accessed June 13, 2025.

Infrastructure systems within the City of Seal Beach, such as roadways, water and wastewater facilities, storm drains, solid waste, electricity, natural gas, telecommunications and circulations provide vital community and individual functions. These facilities and distribution systems are owned, operated, and maintained by the City of Seal Beach and other agencies. The ability for infrastructure systems to remain operational during hazard events and emergencies will contribute to the City’s ability to withstand or recover sooner from hazard events.

The City of Seal Beach is accessible via Interstate 405 (I-405), Interstate 605 (I-605), and State Route 22 (SR-22). Seal Beach has 34 miles of road including both residential streets and main thoroughfares. Principal arterials in the planning area include Pacific Coast Highway (PCH) and Westminster Avenue providing east-west access, and Seal Beach Boulevard providing north-south access. Minor arterials and major collectors support the overall connectivity and transportation system. The roads in Seal Beach are serviced by the City of Seal Beach Public Works Department, with the exception of Pacific Coast Highway, which is under the jurisdiction of California Department of Transportation (Caltrans), and private roads, including all of Leisure World, and smaller streets in the Heron Pointe and Surfside Colony developments. The Street Maintenance City of Seal Beach Local Hazard Mitigation Plan DRi\1 ;[,IBERA, IVE

3.6 INFRASTRUCTURE SYSTEMS

3.6.1 TRANSPORTATION
Section 3. Community Profile September 2025
section of the PWD is responsible for maintaining all city streets, sidewalks, curbs and gutters. The I-405, I-605, and SR-22 are maintained by Caltrans, with the Orange County Transportation Authority (OCTA) involved in improvement projects and overall coordination for the I-405 and SR-22 freeways in this region.

The City of Seal Beach sources approximately 85 percent of its water supply from local groundwater, via three local wells. The remaining demand is met through water supplied by the Municipal Water District of Orange County (MWDOC) via the Metropolitan Water District of Southern California (MWD), originating from Northern California and the Colorado River.

The City of Seal Beach does not have its own wastewater services, instead the City collects wastewater through its local sewer system which consists of 34 miles of sewer lines, six pump stations, and 800 manholes. The City then transports the collected wastewater to the Orange County Sanitation District (OCSD) for treatment.

Southern California Edison (SoCal Edison) provides electricity to the City of Seal Beach. Electricity is distributed from power plants through power lines and substations. Substations within the City include the Norseal Substation (ID SS1184).19 Power lines within the City are both underground and above ground.

Southern California Gas (SoCal Gas) provides gas service to the City of Seal Beach. According to SoCal Gas’s Gas Transmission Pipeline Map, major gas transmission lines are present within the city underneath Lampson Avenue from east to west. Additionally, the City has high pressure distribution lines running through Pacific Coast Highway, Bolsa Ave, Seal Beach Blvd, I-405, I-22, and Bolsa Chica Rd.20
The LHMP Planning Committee identified 88 critical facilities for incorporation in the hazard vulnerability/risk analysis. Seal Beach critical facilities are summarized by asset type in Table 3- 9, City of Seal Beach Critical Facilities. Critical facilities are owned, operated, and maintained mainly by the City and other various agencies. Critical facilities serve an important function in the operations of the municipal government and in serving the community. These facilities include government buildings (police stations, fire stations, community centers, etc.), parks, water and wastewater facilities, public schools, and utilities. Damage to these facilities caused by a hazard event has the potential to impair response and recovery and may lead to disruption of services.

Critical facilities may also assist in evacuations, serve as assembly points or temporary shelters, or provide a supportive role in preparing for and recovering from hazard events. 19 California Energy Commission, Statewide Operational Substations, https://www.energy.ca.gov/search/site?keys=SUBSTATIONS, accessed January 8, 2025. 20 SoCalGas, Gas Transmission Pipeline Interactive Map – Orange, https://socalgas.maps.arcgis.com/apps/webappviewer/index.html?id=53da2bbb31574e0ab0f14f9bc2618 d89, accessed January 13, 2025.
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3.6.3 ELECTRICITY

3.6.4 NATURAL GAS

3.6.5 CRITICAL FACILITIES
September 2025
City of Seal Beach Local Hazard Mitigation Plan
Section 3. Community Profile
Figure 3-3
City of Seal Beach Critical Facilities
City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE Seal Beach Critical Facilities
I
I
I
46 111 -
110 50119
I
I
long Beach
66 ~
,__68)
~
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Seal Beach
Nofonol Wildlife 11:efuge
Los Alamitos
Weslminsler Blvd
Seal Beach
Naval Weapons Station
Legend
,. - , Seal Beach
L,
L - .1 Municipal Boundary
C'i) Critical Facilities
Westminster
Bolso Ave
Edinger Ave
o~----------,2 mnes -$ Source: City of Seal Beach, Esri Projection: California State Plane Coordinate
System Zone 6, NAD 83
Section 3, Community Profile September 2025
Table 3-9
City of Seal Beach Critical Facilities
ID Name Facility Type Community Lifeline
1 3101 ½ N Gate Rd - Potable
water reservoir, well and
pump station.

Water Systems Water Systems
2 2901 Edinger Ave - Sewer lift
pump station
Water Systems Water Systems
3 601 Gardner - Potable water
reservoir and pump station
Water Systems Water Systems
4 Sewer lift pump station - 800
Ocean Ave
Water Systems Water Systems
5 Potable water well - 2700
North Gate Rd
Water Systems Water Systems
6 Potable water well - 3333
Bolsa Chica Rd
Water Systems Water Systems
7 Potable water well - 4307
Lampson Ave
Water Systems Water Systems
8 Sewer lift pump station - 200
Seal Beach Blvd
Water Systems Water Systems
9 Sewer lift pump station -
1776 ½ Adolfo Lopez Dr
Water Systems Water Systems
10 Sewer lift pump station -
2701 Seal Beach Blvd
Water Systems Water Systems
11 Stormwater pump station -
43 ½ Riversea Rd
Water Systems Water Systems
12 Seal Beach Police
Department
Water Systems Water Systems
13 OCFA Fire Station 44 Government Services Safety and Security, Communications
14 OCFA Fire Station 48 Government Services Safety and Security, Communications
15 Seal Beach Marine Safety
Headquarters
Government Services Safety and Security,
Communications
16* OC-35 Import Waterline
Turnout
Transportation Transportation
17 Sewer lift station - 1st St Water Systems Water Systems 18 Stormwater Pump Station -
202 Seal Beach Blvd
(County owned)
Water Systems Water Systems
19 Bridge to Sunset Aquatic
Park (not City-owned)
Transportation Transportation
20 OC San Regional Wastewater
Collections Station
(not City-owned)
Water Systems Water Systems
21 Leisure World Water Well
(inactive)
Water Systems Water Systems
22 OC San Wastewater Station -
(3112 Yellowtail, Rossmoor)
Water Systems Water Systems
23 San Gabriel River Bike Trail
Entry Point
Transportation Transportation
24 Los Cerritos Wetlands
Restoration
Wetlands Safety and security
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
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ID Name Facility Type Community Lifeline
(not City-owned)
25 Hellman Oil Field
(not City-owned)
Oil Field Hazardous Materials
26 Stormwater Pump Station
(County owned)
Water Systems Water Systems
27 Bridge 53C1998 –
San Gabriel River (Local)
Bridge Transportation
28 Bridge 55C0041L –
Los Alamitos Channel
(Local)
Bridge Transportation
29 Bridge 55C0041R –
Los Alamitos Channel
(Local)
Bridge Transportation
30 Bridge 55C0042L - Federal
Storm Channel
(Local)
Bridge Transportation
31 Bridge 55C0042R - Federal
Storm Channel
(Local)
Bridge Transportation
32 Bridge 55C0075 -
Westminster Channel
(Local)
Bridge Transportation
33 Bridge 55C0104 –
Federal Storm Channel
(Local)
Bridge Transportation
34 Bridge 55C0105M -
Pedestrian Walkway
(Local)
Bridge Transportation
35 Bridge 55C0108 –
Bolsa Chica Channel
(Local)
Bridge Transportation
36 Bridge 55C0160 –
Bolsa Chica Channel
(Local)
Bridge Transportation
37 Bridge 53 0060 –
San Gabriel River (State)
Bridge Transportation
38 Bridge 53 0302L –
San Gabriel River
(State)
Bridge Transportation
39 Bridge 53 0302R –
San Gabriel River (State)
Bridge Transportation
40 Bridge 53 1185 –
San Gabriel River (State)
Bridge Transportation
41 Bridge 53 1737H –
San Gabriel River (State)
Bridge Transportation
42 Bridge 55 0010 –
Anaheim Bay (State)
Bridge Transportation
43 Bridge 55 0065 –
Kitt Highway, US Navy RR
(State)
Bridge Transportation
City of Seal Beach Local Hazard Mitigation Plan DRi\1 ;[,IBERA, IVE Section 3. Community Profile September 2025
ID Name Facility Type Community Lifeline
44 Bridge 55 0310 –
Los Alamitos Channel (State)
Bridge Transportation
45 Bridge 55 0334 –
Bolsa Chica Ditch (State)
Bridge Transportation
46 Bridge 55 0347H –
Service Rd (State)
Bridge Transportation
47 Bridge 55 0412L –
Interstate 405 (State)
Bridge Transportation
48 Bridge 55 0412R –
Interstate 405 (State)
Bridge Transportation
49 Bridge 55 0413F –
Rte 405, 605, CONN, RIV
(State)
Bridge Transportation
50 Bridge 55 0415 –
E22 - N405 Connector Ramp
(State)
Bridge Transportation
51 Bridge 55 0426G –
S605 - S405 Connector
(State)
Bridge Transportation
52 Bridge 55 0428G –
State Route 22 (State)
Bridge Transportation
53 Bridge 55 0441 –
Los Alamitos Channel (State)
Bridge Transportation
54 Bridge 55 0471H –
Los Alamitos Channel (State)
Bridge Transportation
55 Bridge 55 1100G –
Interstate 405 (State)
Bridge Transportation
56 Leisure World Clubhouse 1 Community Facility Safety and Security 57 Leisure World Clubhouse 2 Community Facility Safety and Security 58 Leisure World Clubhouse 3 Community Facility Safety and Security 59 Leisure World Clubhouse 4 Community Facility Safety and Security 60 Leisure World Clubhouse 5 Community Facility Safety and Security 61 Leisure World Clubhouse 6 Community Facility Safety and Security 62 Leisure World Healthcare
Center
Healthcare Facility Health and Medical
63 Mary Wilson Library Community Facility Safety and Security, Communications; Food
Water, Shelter
64 McGaugh School Community Facility Safety and Security; Communications; Food,
Water, Shelter
65 North Seal Beach
Community Center
Community Facility Safety and Security;
Food, Water, Shelter
66 Seal Beach Senior Center Community Facility Safety and Security; Food, Water, Shelter
67 Seal Beach Tennis Center Community Facility Safety and Security 68 City Hall Government Building Safety and Security
69 Naval Weapons Station Seal
Beach
Military Facility Safety and Security
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ID Name Facility Type Community Lifeline
70 Police Substation Municipal Services Safety and Security; Communications
71 Seal Beach Ocean Pier Public Park Safety and Security 72 Almond Park Public Park Safety and Security
73 Arbor Park Public Park Safety and Security
74 Aster Park Public Park Safety and Security
75 Bluebell Park Public Park Safety and Security
76 Corsair Park Public Park Safety and Security
77 Electric Avenue Greenbelt Public Park Safety and Security 78 Edison Park Public Park Safety and Security
79 Eisenhower Park Public Park Safety and Security
80 Gum Grove Park Public Park Safety and Security
81 Heather Park Public Park Safety and Security
82 Marina Park + Community
Center
Community Facility Safety and Security
83 Schooner Park Public Park Safety and Security
84 Zoeter Field Public Park Safety and Security
85 Beach Maintenance Yard Government Building Hazardous Materials 86 City Maintenance Yard Maintenance Yard Hazardous Materials 87 College Park Drive Box
Culvert Bridge
Bridge Transportation
88 College Park Drive Bridge
over San Gabriel River
Bridge Transportation
*Critical Facility #16 is outside of Seal Beach Municipal Boundary and not mapped Additionally, it is noted that critical facilities #87 and #88 are located along the only points of egress for the College Park West neighborhood. Critical facility #88 is a major bridge spanning over the San Gabriel River, located just west of Edison Park and running alongside the SR-22 freeway. This bridge is owned and maintained by the City of Long Beach. Critical facility #87 is a small bridge over a box culvert located between Loyola Plaza and Harvard Lane on College Park Drive, just east of Edison Park. This smaller bridge is owned and operated by Orange County Public Works and the Orange County Flood Control District. Failure of these assets could cause cascading impacts that have been addressed within related hazard profiles.

Identification and integration of Socially Vulnerable Populations (SVP) into the hazard mitigation planning process is a new addition from Cal OES and FEMA, as required by the recent Local Mitigation Planning Policy Update. The purpose of this new LHMP section is to identify vulnerable populations within the planning area, along with identifying characteristics that can make individuals more vulnerable to natural and human-caused hazards. The City of Seal Beach includes a total of 10 census tracts. Of the 10 census tracts, three include portions of residencies and properties that are located within adjacent jurisdictions (Rossmoor and Huntington Beach).

Because these census tracts include portions of land in adjacent jurisdictions, the data may be distorted or skewed for the portion within the City of Seal Beach. As a result, demographic information for these tracts reflect neighboring communities as well as Seal Beach. Figure 3-4, City of Seal Beach Census Tracts depicts the census tracts in Seal Beach.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE

3.7 SOCIALLY VULNERABLE POPULATIONS AND DETERMINATIONS

3.7.1 SVP RESEARCH AND METHODOLOGY
Section 3. Community Profile September 2025
Figure 3-4
City of Seal Beach Census Tracts
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan Census Tracts in Seal Beach
., 1100.07
Legend
r - , Seal Beach
L - .1 Municipal Boundary
D Census Tracts
Or---.--,----•2-,miles -$
September 2025
1100.12
995.02
Source: Cal O EHHA, City of Seal Beach, E5ri
Pro1ection: California State Plane Coordinate System Zone 6, NAD 83
Doto Sourced 2021
Section 3. Community Profile
CDC Social Vulnerability Index
The LHMP Planning Team utilized the Center for Disease Control (CDC) Social Vulnerability Index (SVI) to evaluate the presence of socially vulnerable populations. Social vulnerability is defined by the Center for Disease Control and Prevention as characteristics of a person or group that affect their capacity to anticipate, cope with, resist, and recover from the impact of a discrete and identifiable disaster in nature or society. Several socioeconomic factors or other characteristics influence social vulnerability, as illustrated in Figure 3-5, Social Vulnerability Index Themes and Social Factors below.

Figure 3-5
Social Vulnerability Index Themes and Social Factors
Source: CDC and Prevention – National Center for Environmental Health, Planning for an Emergency:

Strategies for Identifying and Engaging At-Risk Groups, published 2015.

US Census and American Community Survey data at the census tract level was utilized to locate and identify socially vulnerable populations within the planning area. The City of Seal Beach is made up of 10 census tracts. The LHMP Planning Team evaluated California-based and national environmental justice definitions and data indices as a method for locating/identifying socially vulnerable populations within the City of Seal Beach.

Figure 3-6, CDC Social Vulnerability Index – Nationwide Comparison (2020), shows the CDC SVI for census tracts within the City. This index was selected because it is most frequently utilized in federal grant evaluations and decision-making, including FEMA hazard mitigation grants. Table 3- 10, Seal Beach Overall Social Vulnerability Index Scores, shows the SVI score and level of City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE [ Below Poverty ]
[ Unemployed ]
[ Income ]
[ No High School Diploma ]
===== ::========::::::::
[ Aged 65 or Older ]
Section 3. Community Profile
[ Aged 17 or Younger ]
( Older than Age 5 with a Oisabiliu
L Single-Parent Households
Minority J
Speak English "Less than Well"
( Multi-Unit Structures ]
( Mobile Homes ]
( Crowding ]
( No Vehicle ]
( Groue Quarters ]
September 2025
vulnerability for census tracts within the City. Possible scores range from 0 (lowest vulnerability) to 1 (highest vulnerability).

Table 3-10
Seal Beach Overall Social Vulnerability Index Scores
Census Tract
Social Vulnerability Index Scores
2022 Statewide Overall SVI Score Level of Vulnerability 995.02 0.3742 Low-Medium
995.04 0.1028 Low
995.06* 0.0680 Low
995.09 0.6926 Medium-High
995.10 0.5261 Medium-High
995.11 0.2271 Low
995.12 0.2812 Low-Medium
1100.12 0.3195 Low-Medium
1100.07* 0.0446 Low
1100.08 0.3338 Low-Medium
*CalEnviroScreen data shows Census Tract 71.11 as 71.09 and was labeled as 71.09 for this table.

Source: Center of Disease Control/Agency for Toxic Substances and Disease Registry, CDC/ATSDR Social Vulnerability Index (SVI), https://www.atsdr.cdc.gov/placeandhealth/svi/interactive_map.html, accessed January 9, 2025.

The CDC Social Vulnerability Index reports two census tracts, 995.09 and 995.10, as having medium to high levels of vulnerability within the City. These two census tracts are almost entirely within the Leisure World community. The remaining census tracts within the City have low and low to medium levels of vulnerability.

Several factors are reported to contribute toward the medium to high vulnerability determinations for census tracts within the City. Census tracts within the City indicate social vulnerability based on 16 indicators identified in the SVI including socioeconomic status, household characteristics, racial/ethnic minority status and housing type/transportation. The SVI flags census tracts in the top ten percent (i.e., the 90th percentile) for these demographic, socioeconomic and housing indicators to indicate a high level of vulnerability. Two census tracts have one or more indicator scores that are within the 90th percentile indicating a high level of vulnerability.

According to the CDC, census tracts in City of Seal Beach were included in the 90th percentile for the following indicators:
• Civilians unemployed
• Percentage of persons aged 65 and older
• Percentage of persons under age 17
• Percentage of persons with a disability
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
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Figure 3-6
CDC Social Vulnerability Index – Nationwide Comparison (2020) City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE CDC Social Vulnerability Index
by Census Tract in Seal Beach
1100.07
Legend
r - , Seal Beach
L - -' Municipal Boundary
Level of Vulnerability
D Low
D Low - Medium
D Medium - High
or-_._ _ _,. ____ 2-,m;les -$
Section 3. Community Profile
1100.12
995.02
Source: CDC SVI, City of Seal Beach, Esri
Projection: California Stole Plane Coordinate System Zone 6, NAO 83
Doto Sourced; 2020
September 2025
Census tract 995.02 (Naval Weapons Station Seal Beach) scored within the 90th percentile for percentage of civilians unemployed. Unemployed persons may have increased vulnerability during disasters due to limited financial resources to prepare, evacuate, and recover from a disaster. Additionally, they may have difficulty accessing essential resources and services such as healthcare, transportation, and emergency assistance. Lastly, unemployed individuals are more likely to live in substandard housing, which may be more susceptible to damage during disasters.

Census tract 995.02 also scored within the 90th percentile for percentage of persons under age 17.

This population may face increased vulnerability during disasters due to limited access to resources such as transportation. Individuals under age 17 may have limited knowledge to prepare and respond to disasters on their own.

Census Tracts 995.09 and 995.10 show a high percentage of residents age 65 and older, primarily due to the presence of Leisure World, a gated community designed exclusively for individuals aged 55 and above. As a unique community within the City of Seal Beach composed of a relatively high concentration of retirees, Leisure World presents a localized concentration of potentially vulnerable individuals in a relatively small area. This localized concentration skews composite percentile approaches to social vulnerability, flagging indicators such as linguistic isolation and poverty as high, while the actual presence of low income (due to fixed senior incomes) and linguistic isolation within these communities is not substantially above the statewide average.

Additionally, regarding linguistic isolation, Seal Beach as a whole does not meet the Statemandated threshold of 5% limited English proficiency (LEP) that would require local agencies to provide translated materials and bilingual services under the Voting Rights Act and DymallyAlatorre Bilingual Services Act.21 The City will continue to monitor data regarding linguistic isolation and other socioeconomic factors and take appropriate action if the overall percentage of non-English speaking residents exceeds this 5% LEP threshold.

Finally, Leisure World residents (Census Tracts 995.09 and 995.10) may face heightened vulnerability during disasters due to a combination of age-related and disability-related challenges. The area has a high concentration of individuals aged 65 and older, many of whom may experience mobility or health issues, limited access to real-time emergency information, and reliance on caregivers who may not always be available. Additionally, these tracts rank in the 90th percentile for persons with disabilities, further compounding risks through potential barriers to evacuation, inaccessible communication formats, dependence on medical equipment, and limited social support networks. Financial constraints may also hinder both preparedness and recovery efforts for this population.

CalEnviroScreen 4.0
In addition to the CDC Social Vulnerability Index, the LHMP Planning Team utilized the CalEPA DAC criteria based on CalEnviroScreen 4.0 to evaluate the presence of socially vulnerable populations. In May 2022, CalEPA used indicators such as pollution burden and population characteristics listed in Table 3-11, CalEnviroScreen 4.0 Indicators. These indicators establish four criteria markers to indicate the presence of a disadvantaged community (DAC) at the census tract level; census tracts meeting one or more criteria are considered disadvantaged. Applicability to the City of Seal Beach is summarized in Table 3-12, Seal Beach Disadvantaged Communities Criteria Evaluation, below. While there are no DAC identified Socially Vulnerable Populations within Seal 21 California Legislative Information, Chapter 17.5 Use of a Foreign Language in Public Services, https://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?lawCode=GOV&division=7.&title=1.&part=&chapter=1

7.5.&article=, accessed June 12, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
Beach, data is presented for all census tracts located within the City. Analysis and findings are discussed where relevant.

Table 3-11
CalEnviroScreen 4.0 Indicators
Category Indicator
Pollution Burden Ozone
PM2.5
Diesel
Drinking Water
Lead
Pesticides
Toxicity Release
Traffic
Cleanup Sites
Groundwater Threats
Hazardous Waste
Impacted Water Bodies
Solid Waste
Population Characteristics Asthma
Low Birth Weight
Cardiovascular Disease
Education
Linguistic Isolation
Poverty
Unemployment
Housing Burden
Source: State of California OEHHA, CalEnviroScreen 4.0 Excel and Data Dictionary, https://oehha.ca.gov/calenviroscreen/maps-data, published October 2021, accessed February 25, 2025.

Table 3-12
Seal Beach Disadvantaged Communities Criteria Evaluation CalEPA DAC Criteria Applicability to City of Seal Beach

1. Census tracts receiving the highest 25% of
overall scores in CalEnviroScreen 4.0.

Not Applicable. The City of Seal Beach does
not have any census tracts listed with
composite scores at 75 or above. Refer to
Table 3-13, below.

2. Census tracts lacking overall scores in
CalEnviroScreen 4.0 due to data gaps but
receiving the highest 5% of CalEnviroScreen 4.0
cumulative pollution burden scores.

Not Applicable. No data gaps are listed in
CalEnviroScreen 4.0 for census tracts within
the City of Seal Beach.

3. Census tracts identified in the 2017 DAC
designation as disadvantaged as required by
SB535, regardless of scores in CalEnviroScreen

4.0. Not Applicable. No census tracts within the
City of Seal Beach were listed in the 2017
DAC designation.

4. Lands under the control of federally
recognized tribes.

Not Applicable. No tribal jurisdiction is
located within the City of Seal Beach.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE Section 3. Community Profile September 2025
All census tracts within Seal Beach have CalEnviroScreen 4.0 composite scores at or below 50, thus no census tract meets the CalEPA definition of disadvantaged community. However, the City of Seal Beach shows unusually high pollution burden reported by CalEnviroScreen 4.0 (shown in Table 3-13, Overall CalEnviroScreen Percentiles). CalEnviroScreen 4.0 composite scores, pollution burden percentiles, and population characteristic percentiles are illustrated in Figure 3-7, CalEnviroScreen 4.0 Pollution Burden by Census Tract in Seal Beach, Figure 3-8, CalEnviroScreen 4.0 Population Characteristics by Census Tract in Seal Beach, and Figure 3-9, CalEnviroScreen 4.0 Composite Scores by Census Tract in Seal Beach respectively. Pollution burden percentile scores include representative data from specific pollution types (ozone, PM 2.5, diesel, lead) and general pollution types (traffic, groundwater threats, impaired water, and drinking water contaminants.

Population characteristics include socioeconomic risk factors such as educational attainment, linguistic isolation, and poverty rates.

Table 3-13
Overall CalEnviroScreen 4.0 Percentiles
Census Tract CalEnviroScreen
Composite Percentile
Pollution Burden
Percentile
Population
Characteristics
Percentile
995.02 50 90 26
995.04 23 91 6
995.06* 7 34 4
995.09 39 64 26
995.10 38 76 20
995.11 14 48 8
995.12 21 63 10
1100.12 26 71 12
1100.07* 50 88 27
1100.08* 29 79 13
* Census Tract includes land and households outside of the City of Seal Beach jurisdiction.

Source: CalEnviroScreen 4.0,
https://experience.arcgis.com/experience/ed5953d89038431dbf4f22ab9abfe40d/page/Indicators/?views =Pollution-Burden#data_s=id%3AdataSource_25-17c3d89e7e2-layer-1%3A579, accessed January 9, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
Figure 3-7
CalEnviroScreen 4.0 Pollution Burden by Census Tract in Seal Beach City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE CalEnviroScreen 4.0
Pollution Burden by Census Tract in Seal Beach
I
1100.07 ~
'"t r _.L
I I
I
I I
l 1100.08 - J
' - ).:J .... 1100.12
- -
' 995.09
995.10
/'"' ,
995.12 , 995.04
X
:. "vi I ' ,1'
I I f ,
•,., 995.11',
Legend \ ....
r - , Seal Beach
L - J Municipal Boundary
Level of Vulnerability (Percentile)
r~
995.06
D >30-40
D >40-50
D >60-70
D >70-80
D >80-90
- >90-100
0 ~-----,----•2-,m;les -$-
Section 3. Community Profile
995.02
,- ---- -
r'
I
Source: Cal OEHHA, City of Seal Beach. Esri
Protection: California State Plane Coordinate Syslem Zone 6, NAO 83
Doto Sourced October 2021
September 2025
Figure 3-8
CalEnviroScreen 4.0 Population Characteristics by Census Tract in Seal Beach DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan CalEnviroScreen 4.0
Population Characteristics by Census Tract
in Seal Beach
;-., 1100.07 "- . I ~ I I
/ l 1100.08 - J ~ ... 1100.12
---
995.09
995.10
\ ......

Legend
r - , Seal Beach
L - .1 Municipal Boundary
Level of Vulnerability (Percentile)
- >0-10
- >10-20
D >20-30
Or---.--,----•2-,miles -$
September 2025
,,
995.02
r- - ------- J
Source: Cal O EHHA, City of Seal Beach, Eui
Pro1ection: California State Plane Coordinate System Zone 6, NAD 83
Doto Sourced October 2021
Section 3. Community Profile
Figure 3-9
CalEnviroScreen 4.0 Composite Scores by Census Tract in Seal Beach City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE CalEnviroScreen 4.0
Composite Scores by Census Tract in Seal Beach
; -., 1100.07 ~ I
/ I
/
1100.08
\. ~ -- -- -
,. ..,
995.09
995.10
,,,/ , 995.12 .... .... 995.04
.... '< I I
" I I
I
/
I ~ 995.11' •
' \ ....

Legend
,. - , Seal Beach
L - J Municipal Boundary
Level of Vulnerability
- > 0-10
- >10-20
D >20-30
D >30-40
D >40-50
o~ _____ ,... ____ 2..,m;les -$-
Section 3. Community Profile
1100.12
,,
995.02
______ __ __ j
Source: Cal OEHHA, City of Seal Beach, Esri
Protection: California State Plane Coordinate Syslem Zone 6, NAO 83
Doto Sourced October 2021
September 2025
In Figure 3-7, high percentile scores indicate disadvantageous outcomes, indicating the City experiences significant pollution burden according to CalEnviroScreen. Five of the 10 census tracts within the City have a score of 75 or higher, meaning these tracts are within the top quarter of pollution burdened census tracts within California. These tracts include Census Tracts 995.02, 995.04, 995.10, 1100.07 and 1100.08. Census Tract 995.02 and 995.04 have the highest Pollution Burden Percentile scores at 90 and 91 respectively, indicating these census tracts are in the top ten percent of pollution burdened communities in California.

Based on the SVI data and other socially vulnerable populations discussed above, the LHMP Planning Team determined that for the purposes of this LHMP, the following Census Tracts would be formally established as an SVP:
• Census Tracts 995.09 and 995.10 are identified as “Medium-High” by the CDC SVI (Census Tracts). These census tracts are comprised of Leisure World Seal Beach, an age 55+ community with multi-family dwelling units.
• Census Tract 995.02, with a CalEnviroScreen 4.0 Pollution Burden score of 90 other indicators showing high levels of social vulnerability, including the highest concentration of minority populations within the City, low income, and unemployment. It is noted that this is a large census tract with a smaller population (reported approximately 600 individuals), which may skew percentile data reporting at the state and national levels.

This census tract is comprised of Naval Weapons Station Seal Beach and housing is restricted to service members and their families.
• Seal Beach Shores Mobile Home Park, located within Census Tract 995.12, as a lower income community within the City. Stakeholder feedback indicated local knowledge of higher incidence of characteristics that contribute social vulnerability.

In addition, CalEnviroScreen 4.0 and CDC data also indicated high prevalence of specific characteristics that contribute to social vulnerability, distributed throughout the community. The characteristics below were reported by stakeholders and members of the public as contributing to social vulnerability within Seal Beach:
• Persons aged 65 or older (seniors)
• Persons under the age of 17 (children)
• Persons with a disability
• Unemployed individuals
• Persons with high pollution burden
• Tourists, visitors and special event attendees
CalEnviroScreen data also indicates high levels of pollution markers distributed throughout Seal Beach. Stakeholders and members of the public attribute these findings due to current and historical land uses such as active military use at Naval Weapons Station and oil refineries, along with the presence of the I-405 freeway. The Environmental Quality Control Board highlighted that Seal Beach often reports high incidence of particulate matter due to sea spray and ocean air. As these findings were not concentrated in a specific census tract, pollution burden and associated impacts were considered for the entirety of the City.

DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan

3.7.2 SVP DETERMINATION
September 2025 Section 3. Community Profile
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Figure 3-10
Socially Vulnerable Populations Determination in Seal Beach City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE Socially Vulnerable Populations
Determination in Seal Beach
Seal Beach Shores
Mobile Home Parks
Legend
r- - , Seal Beach
L - J Municipal Boundary
D Socially Vulnerable Populations
D Other Census Tracts
_I
I
I
o~ _____ ,... ____ 2..,m;les -$-
Section 3. Community Profile
995.02
Source: Cal OEHHA, City of Seal Beach. Esri
Protection: California State Plane Coordinate Syslem Zone 6, NAO 83
Doto Sourced October 2021
September 2025
Table 3-14
Socially Vulnerable Populations and Potential Vulnerability Socially Vulnerable
Populations Potential Characteristics that Enhance Vulnerability Unemployed
individuals
• Economic instability
• Lack of emergency supplies in preparation for disasters • No insurance for housing, vehicles, and/or healthcare • Limited or no transportation
• Limited or no healthcare
• Housing insecurity and/or safe housing
• Lack of financial assistance
Young population
under age 17
• Reliance on adults for protection, care, and decisionmaking • Susceptibility to injuries and illnesses
• Disruption of education leading to gaps in education and development during recovery from disaster
Elderly populations
aged 65 and older
• Mobility challenges during evacuation or accessing safe shelter
• Overlap between persons aged 65 or older and persons
with a disability, such as cognitive impairment, difficulties with independent living or hearing and vision problems
Persons with
disabilities
• Mobility challenges during evacuation or accessing safe shelter
• Communication barriers especially earing or visual
impairments to receive emergency alerts or instructions in a timely manner
• Reliance on medical care medications, or assistive devices • Social isolation leading to lack of communication
Persons with high
pollution burden
• Chronic exposure leading to respiratory and cardiovascular disease
• Natural disasters such as wildfire and wildfire smoke exacerbating preexisting health conditions
• Weakened immune system due to long term exposure
Tourists and visitors • Unfamiliarity with local hazards • Reliance on temporary or rental housing
• Lack of knowledge of local routes and emergency protocols The City hosts various community events throughout the year (Christmas Parade, Run Seal Beach, Classic Car Show, etc.) that cause an influx of people in the area. This sudden influx of residents, visitors, and tourists would put additional strain local resources during a hazard event, potentially overwhelming healthcare facilities, emergency responders, and shelters, which can hinder response efforts and exacerbate the disaster’s impact on both residents and visitors. Additionally, the 2028 Olympic Games will be hosted in various locations across southern California, creating magnified risk to the City of Seal Beach in the event of a disaster before, during, or after the event.

To mitigate these risks, emergency management strategies should include data collection and analysis, public education, resource allocation, collaboration with local businesses and agencies, and regular training or drills. These considerations have been incorporated into the mitigation strategies to reduce risks brought on by tourism.

DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 3. Community Profile
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3.34 After understanding data behind the vulnerability determination for census tracts in Seal Beach, the LHMP Project Management team worked to incorporate stakeholders into the LHMP Planning Team that represent or serve socially vulnerable groups, including:
• Golden Rain Foundation/Leisure World (serving various SVPs) • Seal Beach Lions Club (serving various SVPs)
• Home Instead Senior Care (elderly populations)
• Optum (serving various SVPs)
• It Takes a Village Senior Care (elderly populations)
• Leisure World Information Council (serving various SVPs) Feedback from these stakeholders and the rest of the LHMP Planning team regarding socially vulnerable populations have been included in each hazard profile (Section 5.0 through Section

10.0) and the mitigation strategy (Section 11). Specific connections between the risk assessment and relevant mitigation actions are discussed on a hazard-by-hazard basis within Section 5.0 through Section 10.0.

City of Seal Beach Local Hazard Mitigation Plan DRA ;[,IBERA IVE Section 3. Community Profile September 2025

fB
• The City has identified 9 new hazards as part of the LHMP update. • Considerations for climate change and Socially Vulnerable Populations (SVPs) have been integrated into each hazard profile.

The first step in developing the vulnerability and risk assessment is identifying the hazards. The LHMP Planning Team reviewed the previously prepared 2019 City of Seal Beach Hazard Mitigation Plan, hazard mitigation plans from neighboring jurisdictions, and other relevant information to determine the extent of natural and human caused hazards with the potential to affect the City; refer to Table 2-5, Existing Plans, Studies, Reports, and Other Technical Data/Information.

A discussion of potential hazards during the first LHMP Planning Team meeting resulted in the identification of the natural hazards that pose a potential risk to the City of Seal Beach. Table 4-1, Seal Beach Hazard Identification, summarizes the Planning Team’s discussion of each of the natural hazards and indicates those identified for inclusion in the LHMP.
0 WHAT'S DIFFERENT ABOUT THE 2025
PLAN?
SECTION 4: HAZARDS ASSESSMENT

4.1 HAZARD IDENTIFICATION AND PRIORITIZATION

4.1.1 HAZARD IDENTIFICATION
Table 4-1
Seal Beach Hazard Identification
List of Hazards
Identified
in Previous
LHMP
Include
in
Updated
LHMP
Discussion Summary
Avalanche No No Not applicable. The conditions for
avalanche are not present in Seal Beach
Civil Disturbance No Yes Civil unrest events may occur in the City and therefore are included.

Climate Change Yes Yes Climate change is not profiled as a distinct hazard, but rather a
phenomenon that could exacerbate
hazards. Climate change will be
considered as a factor for relevant
identified hazards.

Coastal Erosion Yes Yes The City is located on the coast in Orange County and therefore may be a risk to the
City.

Coastal Storms Yes Yes The City is located on the coast in Orange County and commonly experiences
coastal storms.

Cyberattacks No Yes Cyberattacks have affected the City in recent history and have therefore been
included.

Dam Reservoir
Failure
Yes Yes The City is susceptible to inundation
caused by dam failure of the Santiago
Creek Dam and Whittier Narrows Dam
and Reservoir.

Disease/Pest
Management
No Yes Vector-borne and infectious disease has
the potential to impact the planning area.

Vector-borne and infectious diseases are
profiled along with pandemic under
human-caused hazards.

Drought Yes Yes Drought is a potential threat to Seal
Beach and has historically impacted the
planning area.

Expansive Soils No No Soils in the planning area are
predominately composed of silty loam
soils with some impervious soils
indicating minimal risk of expansive soils
to the City.

Extreme Heat Yes Yes Extreme heat has the potential to impact Seal Beach. Extreme heat is profiled
under extreme weather hazards.

Flood and Coastal
Flooding
Yes Yes Flooding is a potential threat to Seal
Beach and has historically impacted the
planning area.

Hailstorm No No The LHMP Planning Team determined
that hailstorms do not pose a significant
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City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 4. Hazards Assessment September 2025
List of Hazards
Identified
in Previous
LHMP
Include
in
Updated
LHMP
Discussion Summary
risk to the planning area based upon
limited previous occurrences.

Human-Caused
Hazards
Yes Yes Human-caused hazards are a potential
threat to Seal Beach and have historically
impacted the planning area.

Hurricane No No The LHMP Planning Team determined
that this hazard does not pose a
significant risk to the planning area due
to limited previous occurrences.

Land Subsidence No No The LHMP Planning Team determined that this hazard does not pose a
significant risk to the planning area due
to limited previous occurrences.

Landslide No Yes Landslide are potential threats to Seal Beach and may impact the planning area.

Lightning No No The LHMP Planning Team determined
that this hazard does not pose a
significant risk to the planning area due
to limited previous occurrences.

Pandemic No Yes Pandemic is a potential threat and has
historically impacted Seal Beach.

Pandemic has been profiled under
human-caused hazards.

Sea Level Rise Yes Yes Seal Beach has low-lying coastal areas that are susceptible to sea level rise and
coastal erosion.

Seismic Hazards Yes Yes Seal Beach is located in a seismically active area and seismic hazards including
fault rupture, ground shaking, and
liquefaction pose a risk to the planning
area.

Severe Weather
Hazards
No Yes Severe weather including extreme heat,
heavy rains, Santa Ana winds, and power
outages pose a risk to the planning area.

These hazards have been profiled
together under extreme weather hazards
for organizational purposes.

Terrorism No Yes Terrorist attacks pose a potential threat to the City and have therefore been
included.

Tornado Yes Yes Although tornadoes are rare in Seal
Beach, this hazard does pose a potential
threat to the City.

Tsunami Yes Yes The City is located on the coast and faces potential vulnerability to the tsunami
hazard.

DWT DI lERAT:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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4.4 List of Hazards
Identified
in Previous
LHMP
Include
in
Updated
LHMP
Discussion Summary
Volcano No No Not applicable. There are no active
volcanoes that pose a threat to Seal
Beach.

Wildfire Yes Yes Wildfire is a potential threat to Seal Beach and has been included as a
potential threat to the planning area.

Windstorm Yes Yes Strong winds and windstorms are
potential hazards within Seal Beach.

Strong winds such as Santa Ana Winds
have been detailed under the extreme
weather hazards profile.

The LHMP Planning Team used a spreadsheet-based tool to prioritize the identified hazards by assigning each hazard a ranking based on probability of occurrence and magnitude of potential impact. These rankings were assigned based on a group discussion, knowledge of past occurrences, and familiarity with the City’s vulnerabilities. Four criteria were used to establish the hazard priorities to be addressed in the LHMP:
• Probability (likelihood of occurrence)
• Location (size of potentially affected area)
• Maximum Probable Extent (intensity of damage)
• Secondary impacts (severity of impacts to community)
A value from one to four was assigned for each criterion, where one is the lowest and four is the highest. The four criteria were then weighted based on the LHMP Planning Team’s opinion of each criterion’s importance. To enhance collaboration and discussion regarding hazard rankings, the LHMP Planning Team participated in a live survey through Mentimeter, allowing each LHMP Planning Team member to individually report initial thoughts on probability, location, maximum probable extent, and secondary impacts. Rankings were assigned individually based on knowledge of past occurrences and familiarity with City vulnerabilities. The survey was integrated into the LHMP Planning Team Meeting #1 PowerPoint presentation, and all attendees filled out the survey questions. Results were averaged to provide a group score per hazard, utilizing the weighted value (recommended by FEMA and confirmed by the LHMP Planning Team) based on the importance of the criterion; refer to Table 4-2, Hazard Ranking Methodology.

The hazard rankings were multiplied by weighted factors to obtain a score for each criterion. A higher weight was given to the criterion considered more important or significant. For example, the probability of hazard occurrence received a higher weight than the potential secondary impacts. The scores for location, maximum probable extent (anticipated damage), and secondary impacts for each hazard were added together to determine the total impact score. The total impact score was then multiplied by the overall probability score to determine the final score. The final scores were used to determine the prioritization of each hazard based on the following FEMA recommended scale:

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

4.1.2 HAZARD PRIORITIZATION
Section 4. Hazards Assessment September 2025
• Low Threat: 0 to 12;
• Medium Threat: 12.1 to 42; and
• High Threat: 42.1 to 64.

Table 4-2
Hazard Ranking Methodology
Probability, Location, and Maximum Probable Extent and Secondary Impacts Probability (2.0): Estimate likelihood of occurrence from historical data.

Probability Score
Unlikely – less than 1% probability in next 100 years or has a recurrence interval of greater than every 100 years
1 Somewhat Likely – between 1% and 10% probability in next year or has a recurrence interval of 11 to 100 years
2 Likely – between 10% and 100% probability in next year or has a recurrence interval of 10 years or less
3 Highly Likely – near 100% probability in next year or happens every year 4 Location (0.8): Size of geographical area of community affected by the hazard.

Affected Area Score
Isolated 1
Small 2
Medium 3
Large 4
Primary Impact (0.7): Anticipated damage to a typical facility/structure in the community.

Impact Score
Negligible – less than 10% damage 1
Limited – between 10% and 25% damage 2
Critical – between 25% and 50% damage 3
Catastrophic – more than 50% damage 4
Secondary Impacts (0.5): Estimated secondary impacts to the community at large.

Impact Score
Negligible – no loss of function, downtime, and/or evacuations 1 Limited – minimal loss of function, downtime, and/or evacuations 2 Moderate – some loss of function, downtime, and/or evacuations 3 High – major loss of function, downtime, and/or evacuations 4 Total Score = Probability x Impact, where:

Probability = (Probability Score x Importance)
Impact = (Affected Area + Primary Impact + Secondary Impacts), where:

Affected Area = Affected Area Score x Importance
Primary Impact = Primary Impact Score x Importance
Secondary Impacts = Secondary Impacts Score x Importance Hazard Planning Consideration
Score Range Value Count

0.0 20.0 Low 0

20.1 42.0 Medium 10

42.1 64.0 High 9
The probability of each hazard is determined by assigning a level, from unlikely to highly likely, based on the likelihood of occurrence from historical data. The total impact value includes the affected area, primary impact, and secondary impact levels of each hazard. Each level's score is reflected in the matrix. The total score for each hazard is the probability score multiplied by its DWT DI lERAT:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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importance factor times the sum of the impact level scores multiplied by their importance factors. Based on this total score, the hazards are separated into three categories based on the hazard level they pose to the communities: High, Medium, and Low.

The results from the LHMP Planning Team Meeting #1 survey were compiled and presented during LHMP Planning Team Meeting #2 for further evaluation and discussion. Table 4-3, Hazard Rankings, identifies the final scores and the hazard planning consideration (threat level) for each hazard based on additional discussion with the LHMP Planning Team and the prioritization process described above.

The LHMP Project Management Team decided to identify nine hazards (coastal flood, coastal storms, dam/reservoir failure, drought, extreme heat, seismic hazards, flood hazards, heavy rains, and Santa Ana Winds and tornadoes) as a high hazard planning consideration based on conversations with the LHMP Planning Team.

Many hazards identified by the LHMP Planning Team are recognized to be interconnected or interrelated. Where appropriate, the hazard profiles (presented below) may include references to other hazard profiles (such as including extreme heat within the Extreme Weather Hazards category). As part of the hazard identification and prioritization process, the LHMP Planning Team determined that some hazards could be combined for clarity purposes within a larger hazard category.

Some hazards were expanded or renamed to reflect conditions more accurately for the City of Seal Beach. Thus, for example, the Extreme Weather Hazards profile includes drought, extreme heat, heavy rain, Santa Ana Winds and tornadoes and Public Safety Power Shutoff (PSPS). It is noted that PSPS is not a direct hazard, but a secondary impact from other natural disasters (primarily Santa Ana Winds, but potentially extreme heat and heavy rains as well). The Human-Caused Hazards profile includes hazardous materials spill, terrorism/cyberattacks, civil disturbance/civil unrest, and pandemic. The Seismic Hazards profile includes fault rupture/ground motion and liquefaction.

Table 4-3
Hazard Rankings
Hazard Type Probabil
ity
Impact
Total
Score
Hazard
Planning
Consideration Location Primary
Impact
Secondary
Impacts
Civil
Unrest/Civil
Disturbance
2 2 2 3 18.0 Medium
Coastal Flood 4 2 4 2 43.2 High
Coastal
Storms 4 2 4 2 43.2 High
Dam/
Reservoir
Failure
4 4 2 2 44.8 High
Drought 4 4 2 2 44.8 High
Extreme Heat 4 4 3 3 54.4 High
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 4. Hazards Assessment September 2025
Hazard Type Probabil
ity
Impact
Total
Score
Hazard
Planning
Consideration Location Primary
Impact
Secondary
Impacts
Seismic
Hazards 4 4 4 4 64.0 High
Flood
Hazards 4 4 2 2 44.8 High
Hazardous
Materials
Spill
2 3 3 3 24.0 Medium
Heavy Rains 4 4 3 3 54.4 High
Pandemic 2 3 2 3 21.2 Medium
Public Safety
Power Shutoff
(PSPS)
3 3 2 3 36.0 Medium
Santa Ana
Winds and
Tornadoes
4 4 3 3 54.4 High
Sea-Level Rise
and Coastal
Erosion
4 2 2 2 32.0 Medium
Terrorism/Cy
berattack* 3 3 3 3 36.0 Medium
Tsunami 3 2 3 3 31.0 Medium
Wildfire and
Urban Fire/
Wildfire
Smoke
3 2 2 2 24.0 Medium
*Terrorism and Cyberattacks were originally considered as separate hazards for the purposes of this LHMP.

However, after additional stakeholder coordination and discussions, these hazards were grouped together to reduce plan redundancy.

The following hazards are discussed within the 2025 LHMP, below:
• Coastal and Flood Hazards
o Flood Hazards
o Coastal Storms
o Coastal Flood
o Sea-Level Rise and Coastal Erosion
o Tsunami
o Dam/Reservoir Failure
• Extreme Weather Hazards
o Drought
o Extreme Heat
o Heavy Rains
o Santa Ana Winds and Tornadoes
o Public Safety Power Shutoff (PSPS)
• Landslide
• Seismic Hazards
DWT DI lERAT:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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o Fault Rupture/Ground Motion
o Liquefaction
• Wildfire and Urban Fire Hazards
o Wildfire and Urban Fire
o Wildfire Smoke
• Human-Caused Hazards
o Hazardous Materials Spill
o Terrorism/Cyberattacks
o Civil Disturbance/Civil Unrest
o Pandemic
Climate change has the potential to exacerbate many of the existing hazards in the City. As such, the LHMP Team decided climate change would be included under each applicable hazard profile with a discussion about how each hazard would intersect or become more significant with impacts of climate change. Discussion and analysis related to climate change are discussed as a subsection under each hazard profile included below.

Vulnerability describes how exposed or susceptible an asset is to damage and depends on a number of variables including the asset’s construction, condition, contents, and economic value of functions. A vulnerability analysis predicts the extent of injury/damage on the built environment that may result from a hazard event of a given intensity in a specific area.

The vulnerability assessment considers risks to critical facilities listed in Section 3.0, Community Profile, and to residential and non-residential buildings throughout Seal Beach. Critical facilities serve an important function in the operations of the municipal government and in serving the community. Critical facilities include essential public buildings, police and fire stations, schools, transportation infrastructure, and essential public utility assets. Many facilities may also be vital to evacuations, serve as assembly points or temporary structures, or provide a supportive role in preparing for and recovering from hazard events. While the City owns and maintains most of the listed critical facilities, there are also critical facilities owned by other public agencies or jurisdictions. Direct and indirect impacts were considered as part of the vulnerability assessment as impacts to some facilities may have indirect impacts on other facilities or populations.

The vulnerability/risk assessment below quantifies, to the extent feasible using the best available data, City assets at risk to hazards and estimates potential losses. This section focuses on the profiled hazards and risks specific to the City of Seal Beach.

Each hazard profile in the following section includes a Vulnerability and Risk Assessment section that presents the results using the methodology described below. Replacement and content values for the facilities in each the hazard areas are tallied in each vulnerability table to estimate the total potential losses for each facility.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

4.2 CLIMATE CHANGE CONSIDERATIONS

4.3 VULNERABILITY /RISK ASSESSMENT
Section 4. Hazards Assessment September 2025
For each hazard profiled in Section 5.0 to Section 10.0, a vulnerability/risk assessment is included within the section. The vulnerability/risk assessment gives equal weight to all hazards, regardless of the identified probability. The specific hazard and associated probability are considered as part of the mitigation prioritization, discussed in Section 11.0, Mitigation Strategy. This assessment considers the physical threats to critical facilities, as well as the physical threat to residential and non-residential structures. It should be noted that actual losses will depend on the type, location, magnitude, and extent of the actual hazard event.

Socioeconomic impacts are generally discussed as some hazards have the potential to impact the City in ways beyond physical damages. To confirm at-risk community populations, a detailed parcel analysis investigated the intersection of each mapped natural hazard with development and population vulnerability. The critical facilities listed in Section 3.0, Community Profile, were mapped in GIS and overlaid with mapped hazard areas (those hazards that have a specific or defined geographic area) to determine which assets are located in each hazard area.

Using the comprehensive parcel database from the City of Seal Beach, parcels with residential and non-residential structures were identified within each mapped natural hazard zone. For residential assets, the number of units is reported per hazard zone. Single family homes are assumed to be one unit. The number of residential units then informs an estimate of residents within each hazard zone. The estimate was generated using the 1.90 persons per household identified by the American Community Survey (ACS) 2023 dataset. For non-residential assets, the total structure square footage was calculated.

Hazard areas and critical facility overlays were conducted for: dam reservoir failure, flood, landslide, sea level rise, seismic hazards (fault rupture/ground motion, liquefaction), and tsunami.

It should be noted that the parcel analysis is based on the best available data and is intended for planning purposes only. The City of Seal Beach provided parcel data via shapefile in November 2024. Michael Baker International did not manipulate the data and used the data as it was provided to estimate hazard vulnerabilities. As such, the parcel analysis serves as an estimate of potential losses based on this data snapshot and may not reflect actual or current conditions within the City at the time of LHMP approval.

Maps were not prepared for the following hazards: coastal storms, coastal flood, human-caused hazards (hazardous materials spill, terrorism/cyberattacks, civil disturbance/civil unrest, pandemic), extreme weather hazards (drought, extreme heat, heavy rains, Santa Ana Winds and Tornadoes, Public Safety Power Shutoff (PSPS), and wildfire and urban fire (wildfire and urban fire, wildfire smoke). These hazards are not geographically defined and/or have the potential to affect the entire City. The wildfire/wildfire smoke hazard was not mapped due to the City not being identified within a wildfire hazard area. For the purposes of this LHMP and vulnerability assessment, it is assumed that coastal erosion, human-caused hazards, extreme weather hazards, and wildfire/wildfire smoke could impact the entirety of the planning area, including all critical facilities.

Replacement and content values for the facilities, the number of residents and residential and nonresidential structures in each hazard area are provided where possible, to estimate the potential DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

4.3.1 METHODOLOGY
September 2025 Section 4. Hazards Assessment ' I
losses based on the method described above. Estimations were prepared using replacement values identified in the HAZUS 6.1 Inventory Technical Manual (2024), where appropriate and related land use categories are listed. Some critical facilities have unavailable replacement cost values due to ownership status or unique characteristics that make replacement estimates infeasible.

As required by the recently updated FEMA policy guidelines, a summary of federally declared disasters specifically affecting the planning area within the last five years is included below as Table 4-4. Specific effects are also outlined in the hazard profiles, previous occurrences sections (where applicable) within Section 5.0 through Section 10.0.

Table 4-4
Summary of Declared Disasters Affecting the Planning Area Date
Disaster
Number
Incident
Subcategory
Incident
Description
Incident
Period
Effect on Planning
Area
Federally Declared Disasters
April 3,
2023
DR4699-CACalifornia
Severe Winter
Storms,
Tornadoes,
Flooding,
Landslides,
and Mudslides
Severe
Winter
Storms,
Tornadoes,
Flooding,
Landslides,
and
Mudslides
February
21, 2023 –
July 10,
2023
Seal Beach
experienced heavy
rain during this
disaster in February
2023. Impacts
primarily included
localized flooding in
low-lying areas near
the coast and in
College Park East.

April 13,
2024
DR4769-CACalifornia
Severe Winter
Storms,
Tornadoes,
Flooding,
Landslides,
and Mudslides
Severe
Winter
Storms,
Tornadoes,
Flooding,
Landslides,
and
Mudslides
January
31, 2024 –
February
9, 2024
Seal Beach
experienced heavy
rain during this
disaster in February
2024. Impacts
primarily included
localized flooding in
low-lying areas near
the coast and in
College Park East.

March 13,
2020
DR3428-CABiological COVID-19 January
20, 2020 –
May 11,
2023
The COVID-19
pandemic, caused by
the SARS-CoV-2
virus, began in
December 2019 and
rapidly spread
worldwide, leading
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

4.4 SUMMARY OF FEDERALLY DECLARED DISASTERS AFFECTING THE

PLANNING AREA
Section 4. Hazards Assessment September 2025
Date
Disaster
Number
Incident
Subcategory
Incident
Description
Incident
Period
Effect on Planning
Area
to significant health,
social, and economic
disruptions. As of
2024, Orange County
has confirmed over
550,000 cases and
nearly 7,000 deaths
due to COVID-19.

March 22,
2020
DR4482-CABiological COVID-19 January
20, 2020 –
May 11,
2023
See DR-3428
State Declared Disasters
February
2024
146 Winter Storms Severe
Winter
Storms
February
2024
Seal Beach
experienced heavy
rain and localized
flooding during this
storm.

August
2023
142 Tropical Storm Tropical
Stom Hillary
August
2023
Seal Beach
experienced heavy
rain and localized
flooding during this
tropical storm.

February
2023 to
March
2023
141 Winter Storms Severe
Winter
Storms
February
2023 to
March
2023
Seal Beach
experienced heavy
rain and localized
flooding during this
storm.

December
2022 to
January
2023
140 Winter Storms Severe
Winter
Storms
December
2022 to
January
2023
Seal Beach
experienced heavy
rain and localized
flooding during this
series of storms.

December
2021
127 Winter Storms December
Winter
Storms
December
2021
Seal Beach
experienced heavy
rain and localized
flooding during this
series of storms.

Table 4-5, Risk Assessment Summary Table, shows a summary of critical facilities that intersect with hazard areas in the City. Those facilities that intersect with a hazard area are indicated with a “Yes” in red text. Facilities that do not fall within the hazard area are designated with an “No” in DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

4.5 SUMMARY OF VULNERABILITY
September 2025 Section 4. Hazards Assessment
green text. Risks that were determined using quantitative data include dam reservoir failure, flood, landslide, sea level rise, seismic hazards (fault rupture/ground motion, liquefaction), and tsunami.

Risks such as coastal erosion, human-caused hazards, extreme weather hazards, and wildfire/wildfire smoke are equal throughout the community. Risks such as coastal storms and coastal flooding were determined using the 2 feet sea-level rise assuming coastal flooding would reach 2 feet.

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City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 4. Hazards Assessment September 2025
. . • . '
,mGFSEAL IEAC"H •
WIG DEPART :ENT .. : .

Table 4-5
Risk Assessment Summary Table
No. Facility Name
Coastal
Flooding and
Coastal
Storms
Dam/
Reservoir
Failure
Flood Extreme
Weather Landslide
2 Ft SeaLevel Rise
and Coastal
Erosion
6 Ft SeaLevel Rise
and Coastal
Erosion
Seismic
Hazards
Ground
Motion
Seismic
Hazards
Liquefaction
Tsunami
Urban Fires/
Wildfire
Smoke
Wildfire
1 3101 ½ N Gate Rd -
Potable water
reservoir, well and
pump station.

No Yes No Yes No No No Yes Yes No Yes No
2 2901 Edinger Ave -
Sewer lift pump
station
No Yes No Yes No No Yes Yes Yes Yes Yes No
3 601 Gardner - Potable
water reservoir and
pump station
No No No Yes No No No Yes No No Yes No
4 Sewer lift pump
station - 800 Ocean
Ave
No No Yes Yes No No Yes Yes Yes Yes Yes No
5 Potable water well -
2700 North Gate Rd
No No No Yes No No No Yes Yes No Yes No
6 Potable water well -
3333 Bolsa Chica Rd
No No Yes Yes No No No Yes Yes No Yes No
7 Potable water well -
4307 Lampson Ave
No No No Yes No No No Yes Yes No Yes No
8 Sewer lift pump
station - 200 Seal
Beach Blvd
No No No Yes No No Yes Yes Yes Yes Yes No
9 Sewer lift pump
station - 1776 ½
Adolfo Lopez Dr
No No No Yes Yes No No Yes No No Yes No
10 Sewer lift pump
station - 2701 Seal
Beach Blvd
No Yes No Yes No No Yes Yes Yes No Yes No
11 Stormwater pump
station - 43 ½
Riversea Rd
No Yes No Yes No No Yes Yes Yes Yes Yes No
12 Seal Beach Police
Department
No No No Yes No No No Yes No No Yes No
13 OCFA Fire Station 44 No No No Yes No No No Yes No Yes Yes No 14 OCFA Fire Station 48 No Yes No Yes No No No Yes Yes No Yes No 15 Seal Beach Marine
Safety Headquarters
No No Yes Yes Yes No Yes Yes Yes Yes Yes No
16* OC-35 Import
Waterline Turnout
No No Yes Yes No No No Yes Yes No Yes No
DRAFT DEUBERAi VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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No. Facility Name
Coastal
Flooding and
Coastal
Storms
Dam/
Reservoir
Failure
Flood
Extreme
Weather Landslide
2 Ft Sea-
Level Rise
and Coastal
Erosion
6 Ft Sea-
Level Rise
and Coastal
Erosion
Seismic
Hazards
Ground
Motion
Seismic
Hazards
Liquefaction
Tsunami
Urban Fires/
Wildfire
Smoke
Wildfire
17 Sewer lift station - 1st
St
Yes No Yes Yes No Yes Yes Yes Yes Yes Yes No
18 Stormwater Pump
Station - 202 Seal
Beach Blvd
(County owned)
No No No Yes No No Yes Yes Yes Yes Yes No
19 Bridge to Sunset
Aquatic Park (not
City-owned)
Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes No
20 OC San Regional
Wastewater
Collections Station
(not City-owned)
No Yes No Yes No No Yes Yes Yes No Yes No
21 Leisure World Water
Well (inactive)
No Yes No Yes No No No Yes Yes No Yes No
22 OC San Wastewater
Station - (3112
Yellowtail, Rossmoor)
No Yes No Yes No No Yes Yes Yes No Yes No
23 San Gabriel River Bike
Trail Entry Point
Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes No
24 Los Cerritos Wetlands
Restoration
(not City-owned)
No Yes No Yes No No Yes Yes Yes No Yes No
25 Hellman Oil Field
(not City-owned)
No No No Yes No No Yes Yes Yes No Yes No
26 Stormwater Pump
Station (County
owned)
Yes No Yes Yes Yes Yes Yes Yes Yes No Yes No
27 Bridge 53C1998
–
San Gabriel River
(Local)
Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes No
28 Bridge 55C0041L
–
Los Alamitos Channel
(Local)
Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes No
29 Bridge 55C0041R
–
Los Alamitos Channel
(Local)
Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes No
30 Bridge 55C0042L
-
Federal Storm
Channel
(Local)
Yes Yes No Yes Yes Yes Yes Yes Yes No Yes No
31 Bridge 55C0042R
-
Federal Storm
Channel
Yes Yes No Yes Yes Yes Yes Yes Yes No Yes No
DRAFT DEUBERAi VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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4-16
No. Facility Name
Coastal
Flooding and
Coastal
Storms
Dam/
Reservoir
Failure
Flood
Extreme
Weather Landslide
2 Ft Sea-
Level Rise
and Coastal
Erosion
6 Ft Sea-
Level Rise
and Coastal
Erosion
Seismic
Hazards
Ground
Motion
Seismic
Hazards
Liquefaction
Tsunami
Urban Fires/
Wildfire
Smoke
Wildfire
(Local)
32 Bridge 55C0075
-
Westminster Channel
(Local)
No No Yes Yes Yes No No Yes Yes Yes Yes No
33 Bridge 55C0104
–
Federal Storm
Channel
(Local)
No Yes No Yes No No Yes Yes Yes No Yes No
34 Bridge 55C0105M
-
Pedestrian Walkway
(Local)
No No No Yes No No No Yes No No Yes No
35 Bridge 55C0108
–
Bolsa Chica Channel
(Local)
No No Yes Yes Yes No No Yes Yes No Yes No
36 Bridge 55C0160
–
Bolsa Chica Channel
(Local)
No No Yes Yes No No No Yes Yes No Yes No
37 Bridge 53 0060
–
San Gabriel River
(State)
Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes No
38 Bridge 53 0302L
–
San Gabriel River
(State)
No No Yes Yes Yes No Yes Yes Yes Yes Yes No
39 Bridge 53 0302R
–
San Gabriel River
(State)
No No Yes Yes Yes No Yes Yes Yes Yes Yes No
40 Bridge 53 1185
–
San Gabriel River
(State)
No No Yes Yes Yes No No Yes Yes Yes Yes No
41 Bridge 53 1737H
–
San Gabriel River
(State)
No No Yes Yes Yes No No Yes Yes Yes Yes No
42 Bridge 55 0010
–
Anaheim Bay (State)
Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No
43 Bridge 55 0065
–
Kitt Highway, US Navy
RR (State)
No No No Yes Yes No Yes Yes Yes Yes Yes No
44 Bridge 55 0310
–
Los Alamitos Channel
(State)
Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes No
45 Bridge 55 0334
–
Bolsa Chica Ditch
(State)
No No Yes Yes Yes No No Yes Yes No Yes No
46 Bridge 55 0347H
– No Yes Yes Yes No No No Yes Yes No Yes No
DRAFT DEUBERAi VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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4-17
No. Facility Name
Coastal
Flooding and
Coastal
Storms
Dam/
Reservoir
Failure
Flood
Extreme
Weather Landslide
2 Ft Sea-
Level Rise
and Coastal
Erosion
6 Ft Sea-
Level Rise
and Coastal
Erosion
Seismic
Hazards
Ground
Motion
Seismic
Hazards
Liquefaction
Tsunami
Urban Fires/
Wildfire
Smoke
Wildfire
Service Rd (State)
47 Bridge 55 0412L
–
Interstate 405 (State)
No Yes No Yes No No No Yes Yes No Yes No
48 Bridge 55 0412R
–
Interstate 405 (State)
No Yes No Yes No No No Yes Yes No Yes No
49 Bridge 55 0413F
–
Rte 405, 605, CONN,
RIV (State)
No Yes No Yes No No No Yes Yes No Yes No
50 Bridge 55 0415
–
E22 - N405 Connector
Ramp (State)
No Yes No Yes No No No Yes Yes No Yes No
51 Bridge 55 0426G
–
S605 - S405
Connector (State)
No Yes No Yes Yes No No Yes Yes No Yes No
52 Bridge 55 0428G
–
State Route 22 (State)
No Yes No Yes No No No Yes Yes No Yes No
53 Bridge 55 0441
–
Los Alamitos Channel
(State)
No Yes Yes Yes Yes No No Yes Yes No Yes No
54 Bridge 55 0471H
–
Los Alamitos Channel
(State)
No Yes Yes Yes No No No Yes Yes No Yes No
55 Bridge 55 1100G
–
Interstate 405 (State)
No No No Yes Yes No No Yes Yes No Yes No
56 Leisure World
Clubhouse 1
No Yes No Yes No No Yes Yes Yes No Yes No
57 Leisure World
Clubhouse 2
Yes Yes No Yes No Yes Yes Yes Yes No Yes No
58 Leisure World
Clubhouse 3
No Yes No Yes No No Yes Yes Yes No Yes No
59 Leisure World
Clubhouse 4
No Yes No Yes No No Yes Yes Yes No Yes No
60 Leisure World
Clubhouse 5
Yes Yes No Yes No Yes Yes Yes Yes No Yes No
61 Leisure World
Clubhouse 6
Yes Yes No Yes No Yes Yes Yes Yes No Yes No
62 Leisure World
Healthcare Center
Yes Yes No Yes No Yes Yes Yes Yes No Yes No
63 Mary Wilson Library No No No Yes No No Yes Yes No Yes Yes No 64 McGaugh School No No No Yes No No No Yes No Yes Yes No 65 North Seal Beach
Community Center
No Yes No Yes No No No Yes Yes No Yes No
DRAFT DEUBERAi VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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4-18
No. Facility Name
Coastal
Flooding and
Coastal
Storms
Dam/
Reservoir
Failure
Flood
Extreme
Weather Landslide
2 Ft SeaLevel Rise
and Coastal
Erosion
6 Ft SeaLevel Rise
and Coastal
Erosion
Seismic
Hazards
Ground
Motion
Seismic
Hazards
Liquefaction
Tsunami
Urban Fires/
Wildfire
Smoke
Wildfire
66 Seal Beach Senior
Center
No No No Yes No No Yes Yes No Yes Yes No
67 Seal Beach Tennis
Center
No No No Yes No No No Yes Yes No Yes No
68 City Hall No No No Yes No No No Yes No Yes Yes No
69 Naval Weapons
Station Seal Beach
No No No Yes No No No Yes No No Yes No
70 Police Substation No No No Yes Yes No No Yes Yes Yes Yes No 71 Seal Beach Ocean Pier Yes No Yes Yes No Yes Yes Yes No Yes Yes No 72 Almond Park No No No Yes No No No Yes Yes No Yes No
73 Arbor Park No No No Yes No No No Yes Yes No Yes No
74 Aster Park No No No Yes No No No Yes Yes No Yes No
75 Bluebell Park No No No Yes No No No Yes Yes No Yes No 76 Corsair Park No Yes No Yes No No Yes Yes No Yes Yes No 77 Electric Avenue
Greenbelt
No No No Yes No No Yes Yes No Yes Yes No
78 Edison Park No Yes No Yes No No Yes Yes Yes No Yes No 79 Eisenhower Park No No No Yes Yes No No Yes Yes Yes Yes No 80 Gum Grove Park No No No Yes No No No Yes No No Yes No 81 Heather Park No No No Yes No No No Yes Yes No Yes No 82 Marina Park +
Community Center
No No No Yes No No Yes Yes Yes Yes Yes No
83 Schooner Park No Yes No Yes No No Yes Yes Yes Yes Yes No 84 Zoeter Field No No No Yes No No Yes Yes No Yes Yes No 85 Beach Maintenance
yard
No No No Yes No No No Yes Yes Yes Yes No
86 City Maintenance
Yard
No No No Yes Yes No No Yes No No Yes No
87 College Park Drive
Box Culvert Bridge
Yes Yes Yes Yes No Yes Yes Yes Yes No Yes No
88 College Park Drive
Bridge over San
Gabriel River
No No Yes Yes Yes No Yes Yes Yes Yes Yes No
DRAFT DEUBERAi VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 4. Hazards Assessment
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Flooding occurs when a waterway, either a natural one or an artificial drainage channel, receives more water than it is capable of conveying, causing the water level in the waterway to rise. Depending on how long these conditions last and the amount of water the waterway receives in proportion to its capacity, the rising water level may eventually overtop the waterway’s banks or any other boundaries to the drainage area, resulting in flooding in the surrounding area.

Floods often occur during heavy precipitation events, when the amount of rainwater exceeds the capacity of storm drains or flood control channels. Floods can also happen when infrastructure such as levees, dams, or culverts fail, or when a section of drainage infrastructure fails, and water cannot be drained from an area fast enough. These failures can be linked to precipitation events (e.g., when water erodes away a levee, allowing water to escape and flood nearby areas), or can be a consequence of other emergency situations (e.g., a dam collapsing due to an earthquake).

FEMA defines flood or flooding as a general and temporary condition of partial or complete inundation of normally dry land areas from:
• The overflow of inland or tidal waters;
• The unusual and rapid accumulation or runoff of surface waters from any source; or,
• Mudslides which are proximately caused by flooding and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.
• Collapse or subsidence of land along the shore of a lake or similar body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels that result in a flood as defined above.

SECTION 5: COASTAL AND FLOODING

HAZARD ASSESSMENT

5.1 FLOOD HAZARDS

5.1.1 DESCRIPTION
Floods can be caused by a number of factors, including:
• Weather and climate patterns (e.g., El Niño, La Niña, Pineapple Express, Atmospheric River, etc.)
o El Niño and La Niña are complex weather patterns resulting from variations in ocean temperatures in the equatorial Pacific. Warmer or colder than average ocean temperatures in one part of the world can influence weather around the globe. El Niño and La Niña episodes typically last 9 to 12 months, but some prolonged events may last for years.1
o Pineapple Express is a name given to an atmospheric river on the West Coast. It is a channel in the atmosphere that moves vast amounts of moisture and can result in massive rain showers.
• Hydrologic features such as reservoirs, ponds, lakes, rivers, etc., can have a large impact on the amount of flooding.
• The absorption capacity of the ground depends on the composition of soil and bedrock of the area. Less absorbent soil conditions in addition to lack of proper storm infrastructure can result in flooding.
• Type and density of vegetation is related to moisture absorption affecting the flow of water.
• Patterns of land use/urbanization relates to the pervious and impervious nature of the ground.
• Expected level, age, and condition of flood management infrastructure can impact flooding conditions.
• Large-scale wildfires dramatically alter the terrain and ground conditions. Vegetation absorbs rainfall, reducing runoff. However, wildfires leave the ground charred, barren, and unable to properly absorb water, creating conditions ripe for flash flooding and debris flow. Flood risk remains significantly higher until vegetation is restored – up to five years after a wildfire.2 3
The City of Seal Beach is prone to three types of flooding riverine, localized, and coastal flooding:
• Riverine: Riverine flooding occurs when streams and rivers exceed the capacity of their natural or constructed channels to accommodate water flow and water overflows the banks spilling out into adjacent low-lying, dry land.4 According to the FEMA National Risk Index, the City of Seal Beach has a very high risk of riverine flooding.5 1 NOAA, What are El Nino and La Nina?, https://oceanservice.noaa.gov/facts/ninonina.html, updated June 16, 2024, accessed July 1, 2024.
2 FEMA, Flood Risk Increases After Fires Are Out – Buy Flood Insurance Now, https://www.fema.gov/factsheet/4562/flood-risk-increases-after-fires-are-out-buy-flood-insurance-now, published October 21, 2020, accessed December 26, 2024.
3 FEMA, Glossary: Flood,
https://www.fema.gov/glossary/flood#:~:text=A%20general%20and%20temporary%20condition,inland %20or%20tidal%20waters%3B%20or, updated July 7, 2020, accessed December 24, 2024. 4 FEMA, Riverine Flooding,
https://hazards.fema.gov/nri/riverineflooding#:~:text=Riverine%20Flooding%20is%20when%20streams,low %2Dlying%2C%20dry%20land., accessed December 26, 2024.
5 Ibid.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 • Localized: Localized flooding is the result from storms and run off that overload the drainageways and flows into streets and low lying-areas.6 This type of flooding can block streets, and low-lying areas while flooding homes and businesses such as the lower parts of the floors and basements. Localized flooding tends to recur small impacts accumulated over time which can become major problems in the future. • Coastal: Coastal flooding occurs when low-lying and dry land is submerged by seawater and often occurs as a result of high or rising tides or storm surges.7 The FEMA National Risk Index indicates that a relatively very low coastal flooding risk in the City of Seal Beach.8 For more detailed information on coastal flooding, refer to Section 5.3, Coastal Flood.

Floods can cause extensive damage and pose health risks. The force of a flood is sufficient to carry away large objects and damage structures, causing considerable damage to buildings and infrastructure. In severe instances, floodwaters themselves can destroy structures or move them off their foundation. Floods can saturate and weaken soil, potentially making structures built on them more susceptible to damage or collapse. Flooding can also affect water quality, as large volumes of water can transport contaminants into water bodies and overload storm/wastewater systems. Additionally, large increases in water volume can cause water body erosion and loss of aquatic habitat. Flooding can also cause economic loss to people and government due to the destruction of property and/or infrastructure. Flood events may be particularly destructive when they create conditions conducive to geologic hazards including landslides or debris flows.

Shallow flooding, a type of localized flooding, can also pose health problems to the community.9 This includes:
• Triggering the growth of mold and mildew in buildings which aggravate allergies and asthma;
• An influx of snakes and rodents moving into closer contact with people; • Movement of gasoline, pesticides, fuel oils, chemicals and other substances can be washed into buildings and soaking into soils;
• Breeding of vectors in standing still water which can transmit encephalitis and West Nile Virus; and,
• Straining individuals and families with the stress of dealing with flood impacts.

Floods can also cause severe damage to trees. Flooding can damage trees through oxygen deprivation where flooded soils limit the oxygen supply to tree roots. Flooding can also alter soil pH and structure, affecting nutrient availability and causing leaf chlorosis, leaf drop, and reduced shoot growth. The force of floodwater can physically damage trees by breaking branches, stripping bark, or even uprooting causing them to fall. Flood-stressed trees are also more vulnerable to diseases and pests and may promote fungal infections.
6 Reducing Damage from Localized Flooding: A Guide for Communities, Chapter 2: Localized Flooding, FEMA511 ch2.indd, https://www.fema.gov/pdf/fima/FEMA511-complete.pdf, accessed December 26, 2024.
7 FEMA, Coastal Flooding National Risk Index, https://hazards.fema.gov/nri/coastal-flooding, accessed December 26, 2024.
8 FEMA, Coastal Flooding National Risk Index, https://hazards.fema.gov/nri/map, accessed December 26, 2024.
9 Ibid.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment Flood zones within the City are predominantly situated in known and mapped drainage areas.

Areas in the City classified within the 1.0% annual chance flood hazard zone include portions of the Surfside area, portions of the Naval Weapons Station area, portions of the Seal Beach National Wildlife Refuge, portions of the Old Ranch Golf Course (including the nearby shopping area along Seal Beach Blvd.), docks of Sunset Aquatic Park, and the Los Alamitos Retarding Basin. Much of the City has reduced risk flooding due to levees in place from the San Gabriel River; refer to Figure 5- 1, Flood Hazard Zones. As the City of Seal Beach is relatively flat, the City is susceptible to ponding, a type of flooding that refers to water collecting in a low-lying area.

The extent or magnitude of flooding is measured by percentage and annual chance floods. Flooding areas are classified as 1 in 100 (one percent) or high risk, and 1 in 500 (0.2 percent) or moderate risk of flooding. Areas having a chance of less than 0.2 percent are classified as low-risk areas.

Floods are measured by stream gages that are installed in bodies of water near populated areas (see Table 5-1, Flood Zones Definitions). They are installed and operated by the United States Geological Survey (USGS) and continuously monitor water levels.

Table 5-1
Flood Zones Definitions
Zone Risk
Floodplain – 100-year flood zone (A, AE, AH,

AO, VE)
1% annual flood risk
Floodway – 100-year flood zone (AE) 1% annual flood risk 500-year flood zone 0.2% annual flood risk
Area with reduced flood risk due to levee Reduced flood risk Source: FEMA, FEMA Flood Maps and Zones Explained, https://www.fema.gov/blog/fema-flood-maps-andzones-explained, accessed August 23, 2023.

Seal Beach has experienced numerous flooding incidents, due to the City’s coastal location, aging infrastructure and low-lying coastal geography. While not always reported as larger regional events, localized flooding has occurred during winter storms that overwhelm the drainage system, prompt street closures or parking lot closures, and cause disruptions to residents and businesses.

Varying levels of property damage have been reported during the most recent storms within the last five years. Specific neighborhoods have experienced repeated previous occurrences, such as the College Park East neighborhood where aging infrastructure is no longer sufficient to convey stormwater flows. Other areas susceptible to local flooding include the Main Street/Old Town neighborhoods, particularly low-lying residences south of the pier. Significant localized flooding incidents are summarized below:

Table 5-2
Flood Events Summary in the City of Seal Beach from 2018 – 2024 Date Description
December 2021 A powerful winter storm impacted Seal Beach, bringing flooding, mudslides and debris flows to the city as a result of heavy rain.

The County of Orange, including the City of Seal Beach, issued flash flood warnings. Ahead of the storm, the National Weather City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.1.2 LOCATION/EXTENT

5.1.3 PREVIOUS OCCURRENCES
Section 5. Coastal and Flooding Hazard Assessment September 2025 Date Description
Service also advised that flooding may occur in poor drainage and urban areas as a result of this storm.10
September 2022 Tropical Storm Kay caused heavy rains in Seal Beach, particularly around the First Street Parking Lot and Beach House restaurant.11 The parking lot of the Beach House restaurant was flooded with six inches of muddy water as a result of the storm.

January and
February 2024
A strong storm surge in January breached the winter sand berm and flooded the First Street parking lot. City crews worked to pump floodwater out of the parking lot and located a small sinkhole approximately three feet deep. Waves overtopped the Seal Beach Pier, which was closed to visitors. 12 In Feburary, continued heavy rains caused localized flooding involving street closures, fallen trees and property damage. No injuries were reported. 13
The City’s maintenance program helps to clear storm drains prior to major events and stage portable pumping stations to support the drainage system. The Capital Improvement Plan identifies storm drain improvements to occur at the West End Pump Staton and the Seal Beach Way Storm Drain. The City also distributes sandbags to residents at both fire stations and City parks in advance of major storm events.

Two federally declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• DR-4699-CA – Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides
• DR-4769-CA – Severe Winter Storms, Tornadoes, Flooding, Landslides, and Mudslides Additionally, five state declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• 136: Winter Storms, February 2024
• 142: Tropical Storm Hillary, August 2023
• 141: Severe Winter Storms, February 2023 to March 2023 • 140: Severe Winter Storms, December 2022 to January 2023 • 127: December Winter Storms, December 2021
Refer to Table 4-4, Summary of Declared Disasters Affecting the Planning Area for further details. 10 Patch, Flash Flood Watch, Rain, Mountain Snow Kick Off Seal Beach New Year Eve Weekend, https://patch.com/california/losalamitos/rain-mountain-snow-kick-seal-beach-new-years-eve-weekend, published December 30, 2021, accessed December 26, 2024. 11 CBS, New restaurant, Beach House, in Seal Beach flooded as storm approaches Orange County, https://www.cbsnews.com/losangeles/news/new-restaurant-beach-house-in-seal-beach-flooded-asstorm-approaches-orange-county/, published September 9, 2022, accessed December 26, 2024. 12 Sun News, Waves overwhelm sand berm and flood First Street lot, https://www.sunnews.org/wavesoverwhelm-sand-berm-and-flood-first-street-lot/, published January 4, 2024, accessed December 26, 2024. 13 CBS, Seal Beach businesses, residents cope with aftermath of flooding, https://www.cbsnews.com/losangeles/news/orange-county-sees-rain-during-storm/, updated on February 2, 2024, accessed December 26, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment Figure 5-1
Flood Hazard Zones
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Flood Hazard Zones
Long Beach
66 0"
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Section 5. Coastal and Flooding Hazard Assessment
Los Alamitos
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Westminster Blvd
Seol Beach
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Legend
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Critical Facilities
Westminste r
~
Boise Ave
Edinger Ave
Impacted Critical Facilities

1.0% Annual Chance
Flood Hazard

0.2% Annual Chance
Flood Hazard
Source: FEMA, City of Seal Beach, Esri
Projection: California State Plane Coordinate System Zone 6, NAO 83
Doto Sourced: 2019
September 2025
FEMA defines flood zones based on the probability of occurrence, expressed in a percentage of the change of a flood of a specific extent occurring in any given year. For areas located within the 100- year flood zone, there is a 1 percent chance in a given year that this area will be inundated by flood waters. For moderate flood hazard areas located within the 500-year flood zone, this probability decreases to 0.2 percent. For minimal flood hazard areas, they are located outside of the 0.2 percent annual chance flood.

Given the location of the planning area and based on previous flood events, there is a highly likely probability of a flood event significantly affecting the City of Seal Beach. A highly likely probability means there is a nearly 100 percent probability in the next year or happens every year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that flood events will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team assigned a high hazard planning consideration to the hazards and impacts associated with flood events based upon a somewhat likely probability and expected impacts of future events.

Climate change is likely to have a direct effect on flooding. According to research conducted by the University of California, Los Angeles, California will experience extremely wet and extremely dry seasons by the end of the century. It is predicted that “over the next 40 years, the State will be 300 to 400 percent more likely to have a prolonged storm sequence as severe as the one that caused the legendary California flood more than 150 years ago.”14 This research team confirmed the recent findings from a New York Times article titled “The Coming California Megastorm,” predicting a future superstorm exacerbated by climate change. A warmer climate can carry atmospheric rivers in rapid succession to California, testing the capacity of dams and flood control infrastructure. The risk of a month-long megastorm as modeled and visualized by this article has a one in 50 chance of occurring annually. If global temperatures continue to climb, the likelihood of such a storm could increase to one in 30.15 Thus, flood considerations should continue to remain a mitigation priority into the future. Coastal cities will flood more often and more severely. Research from Princeton and Rutgers Universities found that major coastal flooding, which is expected to occur once every 100 years, will inundate coastal cities an average of 40 times more often by 2050.16
14 UCLA 18Newsroom, Study forecasts a severe climate future for California, https://newsroom.ucla.edu/releases/california-extreme-climate-future-ucla-study, accessed July 12, 2023. 15 New York Times, The Coming California Megastorm,
https://www.nytimes.com/interactive/2022/08/12/climate/california-rain-storm.html, published August 12, 2022, accessed July 2, 2024.
16 Inside Climate News, U.S. Coastal Cities Will Flood More Often and More Severely, Study Warns, https://insideclimatenews.org/news/07062017/coastal-flooding-extreme-sea-level-riseforecast/?gad_source, published June 7, 2017, accessed July 3, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.1.4 PROBABILITY OF FUTURE OCCURRENCES

5.1.5 CLIMATE CHANGE
September 2025 Section 5. Coastal and Flooding Hazard Assessment Coastal storms are intense weather systems that occur along coastlines, characterized by strong winds, heavy rainfall, and significant wave action.17 These types of storms differ from other weather systems in that coastal storms specifically impact coastlines including a combination of high winds, heavy rainfall, and storm surges. Coastal storms can impact critical systems, stormwater infrastructure, emergency facilities, and roadways.18 This can also trigger a Public Safety Power Shutoff (PSPS) event, leaving many residents and commercial buildings without power.

Storm surges are an abnormal water level rise generated by a storm over and above the predicted astronomical tide.19 Storm surges are sensitive to even the slightest changes in storm intensity, forward speed, size (radius of maximum winds), angle of approach to the coast, and the shape and characteristic of the coastline.20 Storm tide is the water level rise due to the combination of storm surge and the astronomical tide. This rise in water level can cause extreme flooding in coastal areas, particularly when storm surge coincides with normal high tide, resulting in storm tides reaching up to 2 feet or more in some cases. Storm surges can travel up rivers and canals, reaching well inland from the coastline.

Storm surges are primarily caused by strong onshore winds of a hurricane or tropical storm. The wind circulation around the eye of a hurricane causes a vertical circulation in the ocean. While in deep water, there is no indication of storm surge because there is nothing to interfere with this circulation. However, once the storm reaches shallower waters near the coast, the vertical circulation is disrupted by the ocean bottom, prohibiting the water from moving downward. Thus, the water begins to move upward and inland, resulting in storm surge. Stronger winds will produce a higher storm surge. A faster storm will produce a higher surge at the immediate coastline, while a slower storm will produce a surge that penetrates farther inland.21 The City of Seal Beach has 1.5 miles of coastline extending from 1st Street to Surfside. The coastal zone of the City includes portions of Old Town, the Seal Beach Wildlife Refuge, Seal Beach Pier, Surfside Colony, and parks along the coastline. Coastal storms carry the potential to affect the entire coastline of Seal Beach and may extend into the rest of the planning area, depending on the extent of the storm. Infrastructure affected by coastal storms tends to be the Seal Beach Municipal Pier, but all coastal areas contain infrastructure that is at risk of future coastal storm damage. 17 Fiveable, Coastal storms, https://library.fiveable.me/key-terms/introduction-climate-science/coastalstorms, accessed December 30, 2024. 18 NOAA, Coastal Storms, https://coast.noaa.gov/digitalcoast/topics/coastal-storms.html, accessed December 31, 2024.
19 NOAA, National Hurricane Center and Central Pacific Hurricane Center, https://www.nhc.noaa.gov/surge/#:~:text=struck%20the%20area.,What%20is%20Storm%20Surge?,to% 20the%20overall%20water%20level., accessed December 30, 2024. 20 Ibid.
21 Ibid.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.2 COASTAL STORMS

5.2.1 DESCRIPTION

5.2.2 LOCATION/EXTENT
Section 5. Coastal and Flooding Hazard Assessment September 2025 Coastal storm events have historically impacted the City of Seal Beach, with a major storm event affecting the City in 1997. Seal Beach has also experienced large waves due to coastal storms in recent history. Recent urban coastal storm events affecting the City in the last five years have been summarized below, along with a major event in 1997:
• September 1997 – Hurricane Nora produced 20-foot waves causing tidal flooding in the City. This is one of the tallest ocean waves recorded in Seal Beach history.22 • January 2023 – 18-foot waves pummeled the Seal Beach pier prompting temporary closure. Part of the boat ramp used by oil platform workers was damaged.23 • December 2024 – 12-foot waves prompted flooding warning to the coast of Seal Beach.24 Two federally declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• DR-4699-CA – Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides
• DR-4769-CA – Severe Winter Storms, Tornadoes, Flooding, Landslides, and Mudslides Additionally, five state declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• 136: Winter Storms, February 2024
• 142: Tropical Storm Hillary, August 2023
• 141: Severe Winter Storms, February 2023 to March 2023 • 140: Severe Winter Storms, December 2022 to January 2023 • 127: December Winter Storms, December 2021
Refer to Table 4-4, Summary of Declared Disasters Affecting the Planning Area for further details.

Given the location of the planning area and based on previous storm events, there is a highly likely probability of a coastal storm event significantly affecting the City of Seal Beach. A highly likely probability means there is a near 100 percent probability of occurrence in the next year or a recurrence interval of every year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that coastal storms will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team assigned a high hazard planning consideration to the hazards and impacts associated with coastal storm events. 22 OC Register, Hurricane Hillary: Here’s what Southern California news looked like last time a tropical storm made landfall in 1939, https://www.ocregister.com/2023/08/19/lets-take-the-look-at-the-last-time-atropical-storm-made-landfall-here-in-1939/, published August 19, 2023, accessed December 31, 2024. 23 East Bay Times, 18-foot waves pummel piers, chunk out sand and flood parking lots along Southern California coast, https://www.eastbaytimes.com/2023/01/08/big-waves-pummel-piers-chunk-out-sandand-flood-parking-lots-along-southern-california-coast/amp/, updated January 8, 2023, accessed December 26, 2024.
24 Patch, 12-Foot Waves Prompt Flood Warning To Seal Beach Coast, https://patch.com/california/losalamitos/12-foot-waves-prompt-flood-warning-seal-beach-coast, published December 23, 2024, accessed December 27, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.2.3 PREVIOUS OCCURRENCES

5.2.4 PROBABILITY OF FUTURE OCCURRENCES
September 2025 Section 5. Coastal and Flooding Hazard Assessment Climate change is likely to have a direct effect on coastal storms and coastal flooding. According to research conducted by the University of California, Los Angeles, California will experience extremely wet and extremely dry seasons by the end of the century. It is predicted that “over the next 40 years, the State will be 300 to 400 percent more likely to have a prolonged storm sequence as severe as the one that caused the legendary California flood more than 150 years ago.”25 A significant effect of coastal storms involves coastal flooding. Coastal flooding occurs when intense offshore systems or storm surges push seawater inland, submerging low-lying and normally dry land above the normal tide level.
26 The FEMA National Risk Index indicates a
relatively very low coastal flooding risk in the City of Seal Beach.27 Every year, the City of Seal Beach installs a winter sand berm in October through mid-November, which is then taken down during Spring Break. The berm extends from the pier to approximately Dolphin Avenue.28
Coastal flood zones within the City primarily include the Surfside area, portions of the Naval Weapons Station, and Old Town. Much of the City has reduced risk of flooding due to levees in place from the San Gabriel River, and Seal Beach constructs sand berms along the coast annually to act as barriers to protect against high tides and storm surges.29 As the City is relatively flat, coastal areas are especially susceptible to ponding, a type of flooding that refers to a type of flooding as a result of water collecting in low-lying areas. The City of Seal Beach has a high risk of coastal flooding along its coastal boundary, with an even higher risk in the northern coastal area of the City.30
The extent or magnitude of flooding is measured by percentage and annual probability of flooding.

Flooding areas are classified as 1 in 100 (one percent) or high risk, and 1 in 500 (0.2 percent) or moderate risk of flooding. Areas having a probability of less than 0.2 percent are classified as lowrisk areas. Floods are measured by stream gages that are installed in bodies of water near 25 UCLA Newsroom, Study forecasts a severe climate future for California, https://newsroom.ucla.edu/releases/california-extreme-climate-future-ucla-study, accessed July 12, 2023. 26 FEMA, Coastal Flooding National Risk Index, https://hazards.fema.gov/nri/coastal-flooding, accessed December 26, 2024.
27 FEMA, Coastal Flooding National Risk Index, https://hazards.fema.gov/nri/map, accessed December 26, 2024.
28 City of Seal Beach Press Release, The City of Seal Beach Announces 2024 Winter Sand Berm Construction, https://www.sealbeachca.gov/Portals/0/Documents/Public%20Works/Press%20Release%20- %202024%20Berm%20Construction.pdf, published October 4, 2024, accessed January 7, 2025. 29 Sun News, Seal Beach planning for sea level rise with vulnerability assessment, https://www.sunnews.org/seal-beach-planning-for-sea-level-rise-with-vulnerability-assessment/, published July 26, 2019, accessed December 31, 2024.
30 NOAA, Coastal Flood Exposure Mapper, Coastal Flood Hazard Composite, https://coast.noaa.gov/floodexposure/#-13091016,3947681,16z, accessed July 3, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.2.5 CLIMATE CHANGE

5.3 COASTAL FLOOD

5.3.1 DESCRIPTION

5.3.2 LOCATION/EXTENT
Section 5. Coastal and Flooding Hazard Assessment September 2025 populated areas. They are installed and operated by the United States Geological Survey (USGS) and continuously monitor water levels.

Table 5-3
Flood Zones Definitions
Zone Risk
Floodplain – 100-year flood zone (A, AE, AH,

AO, VE)
1% annual flood risk
Floodway – 100-year flood zone (AE) 1% annual flood risk 500-year flood zone 0.2% annual flood risk
Area with reduced flood risk due to levee Reduced flood risk Source: FEMA, FEMA Flood Maps and Zones Explained, https://www.fema.gov/blog/fema-flood-maps-andzones-explained, accessed January 14, 2025.

Coastal flood events have also historically impacted Seal Beach and have yielded impacts to City assets in recent history. Recent urban coastal flood events affecting the City in the last five years have been summarized below:
• December 2023 – High surf flooded the City’s restaurant parking for the second time in less than a year.31
• May 2023 – High tides flooded parking lots and neighborhood streets in Seal Beach. One car nearly submerged in water.32
Two federally declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• DR-4699-CA – Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides
• DR-4769-CA – Severe Winter Storms, Tornadoes, Flooding, Landslides, and Mudslides Additionally, five state declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• 136: Winter Storms, February 2024
• 142: Tropical Storm Hillary, August 2023
• 141: Severe Winter Storms, February 2023 to March 2023 • 140: Severe Winter Storms, December 2022 to January 2023 • 127: December Winter Storms, December 2021
Refer to Table 4-4, Summary of Declared Disasters Affecting the Planning Area for further details. 31 ABC 7, Weather, https://abc7.com/high-surf-warning-seal-beach-orange-county-floodingrisk/14248347/, published December 30, 2023, accessed December 26, 2024. 32 CBS News, High tides flood streets and parking lots in seal beach, https://www.cbsnews.com/losangeles/news/high-tides-floods-streets-and-parking-lots-in-seal-beach/, updated May 18, 2023, accessed December 31, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.3.3 PREVIOUS OCCURRENCES
September 2025 Section 5. Coastal and Flooding Hazard Assessment FEMA defines flood zones based on the probability of occurrence, expressed in a percentage of the change of a flood of a specific extent occurring in any given year. For areas located within the 100- year flood zone, there is a 1 percent chance in a given year that this area will be inundated by flood waters. For moderate flood hazard areas located within the 500-year flood zone, this probability decreases to 0.2 percent. For minimal flood hazard areas, they are located outside of the 0.2 percent annual chance flood zone.

Given the location of the planning area and based on previous coastal flood events, there is a highly likely probability of a coastal flood event significantly affecting the City of Seal Beach. A highly likely probability means there is a near 100 percent probability in the next year or happens every year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that coastal flood events will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team assigned a high hazard planning consideration to the hazards and impacts associated with coastal flooding based upon a highly likely probability and expected impacts of future events.

Coastal cities such as Seal Beach are expected to flood more often and more severely. Research from Princeton and Rutgers Universities found that major coastal flooding, which is expected to occur once every 100 years, will inundate coastal cities an average of 40 times more often by 2050.33
Sea-Level Rise
Sea level rise is the increase in the level of the world’s oceans. This phenomenon is primarily driven by multiple factors. The first factor is thermal expansion where the water can warm due to global warming and expand. 34,35 Warmer water occupies more space than cooler water, contributing to sea level rise. The accelerated melting of glaciers and ice sheets also contribute to rising sea levels as global temperatures increase. This meltwater flows into the oceans adding to the overall volume of seawater. Additionally, changes in surface and deep ocean circulation and storm surges can cause sea-level rise (see Figure 5-2, What Cause The Sea Level To Change?).

Due to the effects of increased temperatures, sea-level rise is expected to increase storm frequency. This can result in wave energy moving further inshore, eroding coastal areas of 33 Inside Climate News, U.S. Coastal Cities Will Flood More Often and More Severely, Study Warns, https://insideclimatenews.org/news/07062017/coastal-flooding-extreme-sea-level-riseforecast/?gad_source, published June 7, 2017, accessed July 3, 2024. 34 National Geographic, Sea Level Rise, https://education.nationalgeographic.org/resource/sea-level-rise/, accessed January 7, 2025.
35 European Commission, Rising sea levels due to climate change found to escalate the rate of erosion of rocky shorelines, https://environment.ec.europa.eu/news/rising-sea-levels-due-climate-change-found-escalaterate-erosion-rocky-shorelines-2023-03-29_en, published March 29, 2023, accessed January 7, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.3.4 PROBABILITY OF FUTURE OCCURRENCES

5.3.5 CLIMATE CHANGE

5.4 SEA-LEVEL RISE AND COASTAL EROSION

5.4.1 DESCRIPTION
Section 5. Coastal and Flooding Hazard Assessment September 2025 communities. Sea level rise can often cause flooding in low-lying areas, which can damage infrastructure, homes, and ecosystems (see Section 5.1, Flood Hazards). This phenomenon can also cause saltwater to intrude into freshwater sources, affecting drinking water supplies and agriculture.36
Figure 5-2
What Causes The Sea Level To Change?
Moffatt & Nichol, City of Seal Beach Sea Level Rise Vulnerability Assessment, published July 2019, accessed January 14, 2025.

Coastal Erosion
Coastal erosion is the process by which local sea level rise, strong wave action, and coastal flooding wear down or carry away rocks, soil, and/or sands along the coast.37 During the winter season in California, beaches typically erode, thereby allowing waves to reach further inland and inundate the bottoms of coastal cliffs and beaches. Coastal failure can also occur as result of heightened precipitation, particularly during El Niño events where wave actions can be high. Rainfall may be the ultimate trigger for slope failure, even during times with little to no wave action as rocks and soil are heavily saturated.38
Coastal or shoreline erosion will be the most significant hazard impacting coastal resources due to “coastal squeeze.”39 Coastal squeeze is the process by which sea level dependent physical, cultural, or biological areas are pushed landward with sea level rise but are prevented from 36 United Nations, What is sea level rise and why does it matter to our future?, https://news.un.org/en/story/2024/08/1153596, published August 26, 2024, accessed January 14, 2025. 37 U.S. Climate Resilience Toolkit, Coastal Erosion, https://toolkit.climate.gov/topics/coastal-floodrisk/coastal-erosion, modified April 2021, accessed January 7, 2025. 38 Ibid.
39 Moffatt & Nichol, City of San Clemente Sea Level Rise Vulnerability, published October 2019, accessed January 14, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan What causes the sea level to change?
Terrestrial water storage, e>Ctractioo of groundwater, building ol reservoirs, changes in runoff. and seepage into aquifers
Regional
Factors
Sur1ace and deep ocean circulation changes. storm surges Subsidence In river
delta region, land movements, and
tectonic displacements
1/
As the ocean warms, the water expands
...

INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
Exchange of the water stored on land by
glaciers and ice sheets
with ocean water
Global
Factors
September 2025 Section 5. Coastal and Flooding Hazard Assessment natural landward movement due to a protected or non-erodible structure. The City currently experiences coastal squeeze as sea level rises.

There are several strategies to reduce coastal erosion due to sea-level rise either through gray or green techniques (refer to Figure 5-3, Coastal Erosion Mitigation Strategies). Grey techniques are referred to as shoreline “hardening,” where structures such as seawalls, revetements, groins (medium-sized artificial structure built perpendicular to the shoreline), riprap, and levees are placed to reduce eroding coastal areas.40 Seawalls and riprap may lock potential beach sand in place on cliffs, removing an important source of natural sand replenishment.41 Green techniques use living shorelines, which consist of plants or other natural elements often in combination with harder shoreline structures, to stabilize estuarine coasts, bays, and tributaries.42 Living shorelines improve water quality, provide fisheries habitat, increase biodiversity, and promote recreation.

Coastal erosion strategies can also incorporate components of both gray and green techniques to comprehensively protect shorelines.

Figure 5-3
Coastal Erosion Mitigation Strategies
Source: NOAA, Guidance for Considering the Use of Living Shorelines, https://www.habitatblueprint.noaa.gov/wp-content/uploads/2018/01/NOAA-Guidance-for-Consideringthe-Use-of-Living-Shorelines_2015.pdf, published 2015, accessed January 14, 2025.

According to the Sea Level Rise Vulnerability Assessment prepared by Moffat and Nichol in 2019, the City of Seal of Beach has three distinct regions where the combined effects of sea level rise and 40 U.S. Climate Resilience Toolkit, Coastal Erosion, https://toolkit.climate.gov/topics/coastal-floodrisk/coastal-erosion, updated April 2021, accessed January 7, 2025. 41 Surfrider Foundation San Diego County, The True Cost of Armoring the Beach, https://sandiego.surfrider.org/news/the-true-cost-of-armoring-the-beach, published July 6, 2020, accessed January 7, 2025.
42 Ibid.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE HOW GREEN OR GRAY SHOULD YOUR SHORELINE SOLUTION BE?
- SOFTER TECHNIQUES GRAY-HARDERTECHN
Coastal Structures

EDGING - SILLS - BREAKWATER - REVETMENT - BU
Added structure Parallel to (vegetation Lays over the slope Vertical holds the toe of vegetated opt ional) - Offshore of the shoreline parallel to existing or shorel ine, reduces structures intended and protects it shoreUne vegetated slope wave energy, and to break waves, from erosion and tohold in place. Suitable prevents erosion. reducing the force waves. Suitable for In place for most areas Suitable for most of wave action, and sites with existing for high except high areas except high encourage sediment hardened shoreline settings wave energy wave energy accretion. Suitable structures. with environments. environments. for most areas. shorellne
5-4.2 LOCATION/EXTENT
Section 5. Coastal and Flooding Hazard Assessment September 2025 coastal and fluvial storms could result in flooding of the community. The three areas are listed below and are shown in Figure 5-4, Coastal Setting within the City of Seal Beach. 1) Seal Beach – Open Coast: This coastal reach between the San Gabriel River and Anaheim Bay jetties (East and West Jetty) encompasses West Beach, the Seal Beach Municipal Pier, and East Beach. This is the center of beach-related activity in Seal Beach due to the accessibility and proximity to Main Street, residential development and visitor serving amenities. This area is currently exposed to coastal erosion, flooding, and wave runup (the maximum vertical height that waves reach as they travel up the slope of a beach, revetment, or coastal structure) during extreme events. Sea level rise has the potential to increase the severity of these hazards, impacting the recreational beach areas, amenities, and residential development. 2) Surfside Community – Open Coast: The Surfside Community, south of Anaheim Bay, is also exposed to the open coast and associated process of coastal erosion, wave runup and flooding during extreme events. Located downcoast of complete littoral barrier formed by the Anaheim Bay jetties, this segment of shoreline is particularly vulnerable to erosion and dependent on regular nourishment from the United States Army Corps of Engineers (USACE) to maintain a sandy beach in front of residential development.
3) Inland Low-Lying Areas: Inland low-lying areas of Seal Beach are also susceptible to potential flooding from sea level rise in combination with high tides and fluvial events from sources such as the San Gabriel River, Los Cerritos Wetlands and Anaheim Bay. The low-lying areas include portions of the Electric Avenue corridor and commercial development adjacent to Westminster Boulevard and Leisure World.43
Additionally, Moffatt & Nichol looked at three different sea level rise scenarios in the report: 1.6 ft,

3.3 ft, 4.9 ft, and 6.6 ft. Their findings showed that approximately 3 feet of inundation may occur from 2060 to 2100+, and 6 feet of inundation may occur in 2090 to 2100+ (See Figure 5-5, Sea Level Rise Timeline). The geographic extent from sea-level rise at 2 ft would potentially impact the City, primarily at the Seal Beach National Wildlife Refuge, Anaheim Bay, and coastal areas of the City as shown in Figure 5-6, Critical Facilities in 2 ft Sea Level Rise Zone. However, the geographic extent of sea-level rise at 6 ft would potentially impact much of the City, spanning from the southern boundaries of the City to Interstate 405 as shown in Figure 5-7, Critical Facilities in 6 ft Sea Level Rise Zone.
43 Moffat & Nichol, City of Seal Beach Sea Level Rise Vulnerability Assessment, https://www.sealbeachca.gov/Portals/0/Documents/SealBeach_VA_7.12.19_Draft01.pdf?ver=2019-07-15- 124445-557, July 2019, accessed January 6, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment Figure 5-4
Coastal Setting within the City of Seal Beach
Moffatt & Nichol, City of Seal Beach Sea Level Rise Vulnerability Assessment, published July 2019, https://www.sealbeachca.gov/Portals/0/Documents/SealBeach_VA_7.12.19_Draft01.pdf?ver=2019-07-15- 124445-557accessed January 6, 2025.

Figure 5-5
Sea-Level Rise Timeline
City of Seal Beach Local Hazard Mitigation Plan
Sea level Rise obove '91 -'09 baseline

6.6 f eel (200 cm)

4.9 feet (1 50 cm)

3.3 f eet (100 cm)

1.6 f eet (50 cm)
When might ii
occurr
2090 lo 21 00+
2080 to 21 00+
2060 lo 21 00+
2040 to 2080
•ranges ar• appr<Wmot• and eshmol.d from OPC State of CA SLR Gudanc• 120 18) Section 5. Coastal and Flooding Hazard Assessment

DRA DE,IBERA IVE
September 2025
Figure 5-6
Critical Facilities in 2 ft Sea Level Rise Zone
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan 2 Feet Sea Level Rise Hazard
Zone
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Source: NOAA. Colifomio Coos1ol Commission, USCG,
City of Seal Beach, Esri
Projection: California State Plane Coordinate System Zone 6, NAD83
NOAA2023
September 2025 Section 5. Coastal and Flooding Hazard Assessment Figure 5-7
Critical Facilities in 6 ft Sea Level Rise Zone
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE 6 Feet Sea Level Rise Hazard
Zone
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Section 5, Coastal and Flooding Hazard Assessment
Los Alamitos
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-
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Source: NOAA, California Coastal Comminion, USCG,
City of Seal Beach, Esri
PrOfedion: California State Plane Coordinate System Zone 6, NAO 83
NOAA2023
September 2025
According to the City’s Sea Level Rise Vulnerability Assessment, coastal erosion in the City dates back to the 1950s.44 In 1959, the concrete sheet pile groin along the Seal Beach Municipal Pier was initially constructed to offset effects of wave amplification and prevent undue loss of beach area east of the Pier. In 1964, the United States Army Corps of Engineers began regular beach nourishment cycles at Surfside-Sunset Beach as mitigation for the downcoast shoreline impacts of the Anaheim Bay Jetties and to provide a feeder for the 13 miles of downdrift shoreline. Over 17 million cubic yards have been placed since 1964. Past sand nourishment events at the City have been sporadic and generally supplied by dredge materials from nearby projects, offshore sources or inland sources on an opportunistic basis. Placement of nourished material typically occurs along the east beach to widen the berm and provide a buffer for the winter dike. Recent nourishments have occurred at a frequency of approximately once every 5-7 years as sand is placed immediately downcast of the eastern Anaheim Bay jetty.

No federally or state declared disasters specifically related to sea-level rise and coastal erosion events have impacted the planning area within the last five years. Other disasters related to flooding, storms and heavy rains are referenced in Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Concrete sheet pile groin along the Seal Beach Municipal Pier was initially constructed in 1959 to offset wave amplification and prevent undue loss of each area east of the Pier. Without the concrete sheet pile groin along the Seal Beach Municipal Pier, it is estimated that erosion rates in the area would increase by approximately 50 percent.

Based on previous occurrences and observed risk, there is a likely probability of future coastal impacts in the future. The LHMP planning team assigned a likely probability of a coastal erosion occurring in the future, meaning there is a 10 to 100 percent probability in the next year or a recurrence interval of 10 years or less. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that coastal erosion will likely affect the planning area in the future and therefore felt “likely” best defined probability for this specific hazard. The LHMP planning team assigned a medium hazard planning consideration to the hazards and impacts associated with coastal erosion based on a likely probability and likely expected impacts of future events. Throughout the planning area, much of the coastal areas are susceptible to coastal erosion and have already experienced impacts and loss.

Coastal counties produce more than $9.5 trillion in goods and service each year and support more than 58 million jobs in fishing, tourism, real estate, defense, and other industries.45 Coastal communities can face permanent inundation and flooding threats from climate change effects such 44 Moffatt & Nichol, City of Seal Beach Sea Level Rise Vulnerability Assessment, https://www.sealbeachca.gov/Portals/0/Documents/SealBeach_VA_7.12.19_Draft01.pdf?ver=2019-07-15- 124445-557, published July 2019, accessed March 5, 2025. 45 Environmental Protection Agency, Climate Change Impacts on Coasts, https://www.epa.gov/climateimpacts/climate-change-impacts-coasts, updated on November 16, 2023, accessed January 7, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.4.3 PREVIOUS OCCURRENCES

5.4.4 PROBABILITY OF FUTURE OCCURRENCES

5.4.5 CLIMATE CHANGE
September 2025 Section 5. Coastal and Flooding Hazard Assessment as sea level rise, intense rains, high tide flooding, and severe storms.46 Climate change can cause coastal land losses to occur by turning dry land into wetlands or open water.47 In addition, a higher increase in sea-level rise may also increase residential displacement along Seal Beach coastal communities, as well as impacting infrastructure and services in the planning area.

A tsunami is a wave or series of waves generated by a large and sudden upward movement of the ocean floor or other natural disturbances. Usually, tsunamis occur because of an earthquake below or near the ocean floor. Volcanic eruptions, landslides, and in rare instances meteorites may also trigger tsunamis. The sudden and forceful displacement of the ocean floor creates waves that radiate outward in all directions away from their source, sometimes crossing entire ocean basins.48 In the open ocean, a tsunami travels 500 to 600 miles per hour but is only a few feet in height and may be undetectable by ships. Once the wave nears the shore, the shallow depth pushes against the motion of the wave, causing it to decelerate and increase in height.49 Figure 5-8, How a Tsunami Works, illustrates the factors that lead to the formation of a tsunami wave.

Tsunamis typically rush ashore in multiple waves like fast-rising tide with powerful currents.

When the tsunami makes landfall, the wave can violently disperse inland, causing immense damage and risk of injury or death. These waves often travel much further inland than normal waves. Most tsunami damage is caused by these strong currents and floating debris.50 Tsunamis are generally unpredictable, and the only warning sign is often the earthquake that triggers it. However, the initial earthquake may occur far away and be imperceptible to people on land. The trough of the tsunami is the low point beneath the crest of the wave. This trough often reaches shore first and produces a vacuum effect, which pulls coastal water seaward and exposes the harbor and sea floors. This is one of the few warning signs or indicators that the wave crest and full force of the tsunami will soon hit the coast.51 Tsunamis may last for hours, and additional waves may continue to impact coastlines. This leads to the destruction or damage of structures, disruption of transportation, power, and communications, and more.52 Damages often depend on the size and nature of the earthquake or other tsunami catalysts, as well as the location. Earthquakes and corresponding tsunamis that occur further away are less impactful than those that occur close to the coast. Tsunami damage 46 Ibid.
47 Ibid.
48 FEMA, Understanding Tsunamis, https://www.fema.gov/fact-sheet/understanding-tsunamis, accessed December 27, 2024.
49 National Oceanic and Atmospheric Administration, Tsunami Propagation, https://www.noaa.gov/jetstream/tsunamis/tsunami-propagation, accessed December 27, 2024. 50 United States Geological Survey, Tsunamis and Tsunami Hazards, https://www.usgs.gov/specialtopics/water-science-school/science/tsunamis-and-tsunami-hazards, accessed December 27, 2024. 51 FEMA, Understanding Tsunamis, https://www.fema.gov/fact-sheet/understanding-tsunamis, accessed December 27, 2024.
52 FEMA, Understanding Tsunamis, https://www.fema.gov/fact-sheet/understanding-tsunamis, accessed December 27, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.5 TSUNAMI

5.5.1 DESCRIPTION
Section 5. Coastal and Flooding Hazard Assessment September 2025 may range from minor to devastating, with the worst tsunamis resulting in severe structural and property damage, and substantial loss of life.

Figure 5-8
How a Tsunami Works
Source: National Weather Service, Tsunami Preparedness, https://www.weather.gov/wrn/fall2018-tsunamism, accessed December 27, 2024.

Approximately 80% of tsunamis occur within the Pacific Ocean’s “Ring of Fire,” a geologically active area where tectonic shifts make volcanoes and earthquakes common.53 The Ring of Fire surrounds the Pacific tectonic plate along the east coast of Asia and along the west coast of North and South America. All coastlines are potentially vulnerable to tsunamis that occur in the Pacific, including the southern California coastline that includes the City of Seal Beach.54 The entire 42-mile coastline of Orange County faces vulnerability to the tsunami hazard, which includes coastal communities in the City of Seal Beach. These communities are densely populated, making evacuation efforts a challenge in the event of an emergency. Other factors impacting evacuation include the time of day, the time of year, road conditions, tourist population, and sporting and social events. Tsunami hazard events are rare for southern California, as the state’s coastline is protected by the region’s ocean floor geography and the presence of the Channel Islands, which help to reduce the coastline’s vulnerability to tsunamis.55 Tsunamis impacting the 53 National Geographic, Tsunamis,
https://www.nationalgeographic.com/environment/article/tsunamis#:~:text=Most%20tsunamis%E2%80 %93about%2080%20percent,underwater%20landslides%20or%20volcanic%20eruptions., accessed December 27, 2024.
54 United States Geological Survey, Tsunamis and Tsunami Hazards, https://www.usgs.gov/specialtopics/water-science-school/science/tsunamis-and-tsunami-hazards, accessed December 27, 2024. 55 Tsunami.org, What Causes a Tsunami?, https://tsunami.org/what-causes-a-tsunami/, accessed December 27, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan Most tsunamis are caused by large earthquakes below or near the ocean floor.

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5.5.2 LOCATION/EXTENT
September 2025
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Section 5. Coastal and Flooding Hazard Assessment
planning area are considered unlikely to be large walls of waves, but rather choppy waters resulting in unsafe swimming and boating conditions, and coastal flooding.

In more extreme scenarios, scientists estimate that if a tsunami hits the Orange County coast, it could generate waves greater than 30 feet high.56 An impact of this magnitude could cause loss of life, destroy thousands of homes, greatly affect coastal businesses, and impact tourism. Even if all residents and visitors were safely evacuated, the damage to property in this densely populated, high property value area would still be tremendous. 57
The City of Seal Beach’s proximity to fault lines just off its coastline and running through the City increases the potential of a Local Source Tsunami striking the City’s coastline. Historically, DistantSource Tsunamis, like the one generated in Chile in 1960, have caused significant damage to the California coast. Additionally, there is concern that an earthquake event along the Cascadia subduction zone may have significant impact on southern California, similar to those experienced in Crescent City after the 1964 Alaskan earthquake. With the distance between Cascadia and southern California being about the same as the distance from Alaska to Crescent City, this earthquake scenario poses a threat to the City of Seal Beach.58 According to the Federal Emergency Management Agency (FEMA) National Risk Index (NRI) for natural hazards, Orange County and the City of Seal Beach face a relatively low risk of tsunami impacts. The NRI considers a combination of expected annual loss, social vulnerability, and community resilience ratings to determine relative risk for natural hazard such as tsunami, as shown in Figure 5-9, Tsunami Hazard Zone.

Tsunami damages are closely tied to the magnitude and severity of these on-shore or off-shore earthquake triggers; refer to Section 8.0, Seismic Hazard Assessment, for the magnitude and severity of earthquakes. In the worst-case scenario, tsunamis may cause severe and widespread structural and property damage and substantial loss of life.

The City of Seal Beach has been impacted by two tsunami hazard events in recent history. On September 16, 2015, following a magnitude 8.3 earthquake off the coast of Chile, the National Tsunami Warning Center issued a tsunami advisory for coastline areas from Orange County to north of San Luis Obispo. No coastal flooding resulted from this incident, and tsunami wave heights were observed to be just under one foot along the Orange County coastline.59 56 UNESCO, Tsunami: The Great Waves, https://unesdoc.unesco.org/ark:/48223/pf0000148609, published 2005, accessed December 27, 2024.
57 County of Orange, 2018 Tsunami Annex, https://www.san-clemente.org/about-us/advancedcomponents/document-folder/-folder-34, accessed December 27, 2024. 58 Bourgeois, Michaela, Cascadia Subduction Zone study reveals area at particular risk for massive quake, https://www.koin.com/news/environment/earthquakes/cascadia-subduction-zone-study-earthquakequake-pacific-northwest-june-2024/, accessed December 27, 2024. 59 NOAA, Storm Events Database,
https://www.ncdc.noaa.gov/stormevents/listevents.jsp?eventType=%28Z%29+Tsunami&beginDate_mm= 03&beginDate_dd=01&beginDate_yyyy=1950&endDate_mm=03&endDate_dd=31&endDate_yyyy=2024&co unty=ORANGE%3A59&hailfilter=0.00&tornfilter=0&windfilter=000&sort=DT&submitbutton=Search&stat efips=6%2CCALIFORNIA, accessed December 27, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.5.3 PREVIOUS OCCURRENCES
Section 5. Coastal and Flooding Hazard Assessment September 2025 Figure 5-9
Tsunami Hazard Zone
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan Tsunami Hazard Zone
long Be a ch
66 ~
-'68\
~
Seol Beoch
Notional Wildlife Refuge
Los Alamitos
Westminster Blvd
Seal Beoch
Naval Weapons S!otion
r - , Seal Beach
I
I
I
®
I
I
I.,
" - J Municipal Boundary
Q Critical Facilities
Westminster
~
Bolso Ave
Edinger Ave
G) Impacted Critical Facilities
Tsunami Hazard Zone
or-----------,2 mnes -$ Source: CA Dept. of Conservation, City of Seal Beach, EMi Projection: California State Plane Coordinate System Zone 6, NAD 83
Doto Sourced: 2023
September 2025 Section 5. Coastal and Flooding Hazard Assessment On January 15, 2022, a tsunami advisory was issued for Orange County. Wireless Emergency Alerts and tsunami sirens were activated before the first tsunami wave impacted the coastline. Minor damage was reported along the coast, but no injuries or deaths resulted from this incident.60 No federally declared disasters relating to tsunami events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Earthquakes and tsunamis will continue to occur throughout the Pacific Ocean. Significant tsunami impacts to Seal Beach are rare, and a tsunami is not generally expected to impact the coastline near the planning area. Despite this, the coastal areas of Seal Beach could be susceptible to smaller earthquakes and tsunamis generated from nearby faults and volcanic activity.

It is difficult to predict the recurrence and magnitude of tsunamis. Given the location of the planning area, the amount of low-lying coastal features throughout the City, and the previous history of tsunami occurrence in the Pacific Ocean, it has been determined that the probability of tsunami impacting the planning area in the future is considered likely. A likely probability means a probability of between 10 and 100 percent in the next year or has a recurrence interval of 10 years or less. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that tsunami events will likely affect the planning area in the future and therefore felt “likely” best defined probability for this specific hazard. The LHMP planning team assigned a medium hazard planning consideration to the hazards and impacts associated with tsunamis based upon a likely probability and limited expected impacts of future events.

Climate change is not directly tied to the probability of tsunami occurrence. Tsunami triggers including earthquakes, volcanic eruptions, and landslides are not expected to occur more frequently or be more severe due to climate change. However, sea level rise due to climate change may increase the severity of damages due to tsunamis. Increased mean sea levels would potentially cause tsunami waves and surges to travel further inland. Tsunami impacts would therefore be exacerbated by sea level rise and would cause more destruction and potential loss of life. This nexus between climate change and tsunami suggests that mitigation of climate change and sea level rise would indirectly mitigate the severity of tsunami impacts.

A dam is an artificial barrier preventing the flow of water or a barrier built across a watercourse for impounding water. Dam failure is the uncontrolled release of impounded water from behind a dam. Flooding, earthquakes, blockages, landslides, lack of maintenance, improper operation, poor construction, vandalism, and terrorism can all cause dam infrastructure to fail. Dam failure causes downstream flooding of varying velocities that can result in loss of life and property. Reservoirs 60 Ibid
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.5.4 PROBABILITY OF FUTURE OCCURRENCES

5.5.5 CLIMATE CHANGE

5.6 DAM/RESERVOIR FAILURE

5.6.1 DESCRIPTION
Section 5. Coastal and Flooding Hazard Assessment September 2025 are defined as an artificial lake, pond, impoundment, or tank, used to store water (both potable and non-potable). Reservoirs can be created on the surface by constructing dams to store water.

Additionally, tank reservoirs can be constructed to store water above ground, on the surface, or below ground. Reservoir failure is the uncontrolled release of impounded water from a reservoir.

Dam or reservoir failures are most likely to happen for the following reasons:61 • Overtopping, caused by water spilling over the top of the dam, usually a precursor of dam failure because of inadequate spillway design, debris blockage of spillways, or settlement of the dam crest;
• Foundation defects, including settlement or slope stability; • Cracking caused by natural settling of a dam or seismic movements; • Inadequate maintenance and upkeep; and/or
• Piping, when seepage through a dam is not properly filtered, soil particles continue to progress and form sinkholes in the dam.

Because dam failure can have severe consequences, FEMA and Cal OES require all dam owners to develop an Emergency Action Plan (EAP) for warning, evacuation, and post-flood actions. In the event of a major dam failure, mutual aid from all levels of government would be required for an extended period. Recovery efforts would include the removal of debris, clearing roadways, demolishing unsafe structures, assistance in reestablishing public services, and providing continued care for the affected population. There are two dam inundation zones within the City of Seal Beach: The Santiago Creek Dam and the Whittier Narrows Dam and Reservoir.

The Santiago Creek Dam is jointly owned by the Irvine Ranch Water District and the Serrano Water District. The Irvine Ranch Water District recently implemented the Dam Safety Program, which uses a Risk-Informed Decision-Making process to identify and reduce dam risk. 62 Dams in Orange County are regulated by the Department of Water Resources, Division of Safety of Dams (DSOD). DSOD ensures dam safety by:63
• Reviewing and approving dam enlargements, repairs, alterations, and removals, and ensuring that the dam appurtenant structures are designed to meet minimum requirements;
• Performing independent analyses to understand dam and appurtenant structures performance (including structural, hydrologic, hydraulic, and geotechnical evaluations); • Overseeing construction to ensure work is performed in accordance with approved plans/specifications;
• Inspecting each dam on an annual basis to ensure safety and performance standards; and • Periodically reviewing the stability of dams/major appurtenances, as well as new findings regarding earthquake hazards and hydrologic estimates in California. 61 Association of State Dam Safety Officials, Dam Failures and Incidents, https://damsafety.org/dam-failures, accessed December 24, 2024.
62 Irvine Ranch Water District, Dam Safety Program,
https://www.irwd.com/images/pdf/construction/DSP_Guidelines_-_July_2023.pdf, accessed December 31, 2024.
63 California Department of Water Resources, Division of Safety of Dams, https://water.ca.gov/Programs/All-Programs/Division-of-Safety-of-Dams, accessed December 31, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment The DSOD is responsible for assigning each jurisdictional dam a downstream hazard classification.

This classification is based only on potential downstream impacts to life and property, should the dam fail when operating with a full reservoir. This hazard status is not related to the condition of the dam or the likelihood of the dam failing in either the short- or long-term. Additionally, dams in southern California usually do not operate at full capacity at all times of the year, and thus hazard risks and classifications are a worst-case scenario assessment. The DSOD definitions for downstream hazards are borrowed from the Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures, and are outlined in Table 5-4, DSOD Downstream Hazard Potential Classification Levels.

Table 5-4
DSOD Downstream Hazard Potential Classification Levels
Downstream Hazard
Potential Classification Potential Downstream Impacts to Life and Property Low No probable loss of human life and low economic and environmental losses. Losses are expected to be principally limited to the owner’s property.

Significant No probable loss of human life but can cause economic loss, environmental damage, impacts to critical facilities, or other significant impacts.

High Expected to cause loss of at least one human life.

Extremely High Expected to cause considerable loss of human life or would result in an inundation area with a population of 1,000 or more.

Source: California Department of Water Resources, Division of Safety of Dams, Definitions of Downstream Hazard and Condition Assessment, https://water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/AllPrograms/Division-of-Safety-of-Dams/Files/Publications/Division-of-Safety-of-Dams-Definitions-forDownstream-Hazard-and-Condition-Assessment.pdf, published September 2021, accessed July 5, 2024.

DSOD inspects dams once annually and provides a condition assessment. This condition assessment is a more accurate tool to evaluate infrastructure risk. DSOD uses the National Inventory of Dams (NID) condition rating definitions, with additional criteria, as a guideline in assigning condition assessments. This rating system is outlined in Table 5-5, DSOD Condition Assessment Rating Levels.

Table 5-5
DSOD Condition Assessment Rating Levels
Rating National Inventory of Dams Definitions California DSOD Additional Criteria
Satisfactory No existing or potential dam safety
deficiencies are recognized. Acceptable
performance is expected under all loading
conditions (static, hydrologic, seismic) in
accordance with the applicable regulatory
criteria or tolerable risk guidelines.

None
Fair No existing dam safety deficiencies are
recognized for normal loading conditions.

Dam has a long-standing
deficiency that is not being
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 Rating National Inventory of Dams Definitions California DSOD Additional Criteria
Rare or extreme hydrologic and/or seismic
events may result in a dam safety deficiency.

Risk may be in the range to take further
action.
addressed in a timely
manner.

Dam is not certified, and its
safety is under evaluation.

Dam is restricted and
operation of the reservoir at
the lower level does not
mitigate the deficiency.

Poor A dam safety deficiency is recognized for
loading conditions that may realistically
occur. Remedial action is necessary. A poor
rating may also be used when uncertainties
exist as to critical analysis parameters that
identify a potential dam safety deficiency.

Further investigations and studies are
necessary.

Dam has multiple
deficiencies or a significant
deficiency that requires
extensive remedial work.

Unsatisfactory A dam safety deficiency is recognized that requires immediate or emergency remedial
action for problem resolution.

None
Not Rated The dam has not been inspected, is not
under State jurisdiction, or has been
inspected but, for whatever reason, has not
been rated.

None
Source: California Department of Water Resources, Division of Safety of Dams, Definitions of Downstream Hazard and Condition Assessment, https://water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/AllPrograms/Division-of-Safety-of-Dams/Files/Publications/Division-of-Safety-of-Dams-Definitions-forDownstream-Hazard-and-Condition-Assessment.pdf, published September 2021, accessed July 9, 2024.

Dam or reservoir failure within highly urbanized areas like the City can be catastrophic and result in property damage, destruction, and loss of life. Reservoirs in Orange County are regularly inspected and monitored to ensure structural integrity and safety; thus, most issues are identified early and immediately rectified to prevent dam failure. Dam failures can also increase in magnitude and severity when coupled with other natural disasters. Earthquakes or heavy rains can threaten the structural integrity of dam/reservoir infrastructure and create challenging conditions for emergency response.

For dams owned and operated by the United States Army Corps of Engineers (USACE) the Dam Safety Action Classification System (DSAC) is used based on their inspections to determine the probability of failure and potential safety, economic and environmental risks. This rating system is outlined in Table 5-6, USACE Dam Safety Action Classification System.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment Table 5-6
USACE Dam Safety Action Classification System
Dam Safety
Action Class
Safety
Characteristics
Description
DSAC I (Urgent
and
Compelling)
Unsafe; Critically
near failure or
extreme high risk
Dams where progression toward failure is
confirmed to be taking place under normal
operations, and the dam is almost certain to fail
under normal operations within a time frame from
immediately to within a few years without
intervention; or the combination of life or
economic consequences with probability of failure
is extremely high.

DSAC II (High
Urgency)
Unsafe or Potentially
Unsafe; Failure
initiation foreseen or
very high risk
Dams where failure could begin during normal
operations or be initiated as the consequence of an
event. The likelihood of failure from one of these
occurrences, prior to remediation, is too high to
assure public safety; or the combination of life or
economic consequences with probability of failure
is very high.

DSAC III
(Moderate
Urgency)
Conditionally Unsafe;
Significantly
inadequate or
moderate to high risk
Dams that have issues where the dam is
significantly inadequate, or the combination of life,
economic or environmental consequences with
probability of failure is moderate to high.

DSAC IV (Low
Urgency)
Marginally Safe;
Inadequate with low
risk
Dams are inadequate with low risk such that the
combination of life, economic or environmental
consequences with a probability of failure is low,
and the dam may not meet all essential USACE
engineering guidelines.

DSAC V
(Normal)
Adequately Safe;
Residual risk
considered tolerable
Dams considered adequately safe, meeting all
essential agency guidelines, and the residual risk is
considered tolerable.

Source: USACE, Dam Safety Program, https://www.usace.army.mil/Missions/Civil-Works/Dam-SafetyProgram/Program-Activities/, updated December 16, 2021, accessed March 5, 2025.

The City of Seal Beach can also be impacted with flooding if levees near the City fail. Levees are embankments or raised structures built along rivers, lakes, or other bodies of water to prevent flooding. The U.S. Army Corps of Engineers (USACE) Los Angeles District is responsible for inspection of the levees to identify any deficiencies that could be hazardous. Levees are built by piling soil, sand, or rocks on a cleared, level surface. There are four different types of levees:
• Earthen levees: primarily made from compacted soil and are the most prevalent type.

They are used extensively along rivers and flood control channels. • Concrete Levees: Often found in urban areas, these levees are reinforced with concrete to provide additional strength and durability.
• Rock Levees: Constructed with large rocks or riprap, these are used in areas with high erosion potential.

City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 • Floodwalls: Vertical structures made from concrete or steel, often used in conjunction with levees to provide additional protection in densely populated areas.

The geographic extent from dam or reservoir failure is dependent on the type of infrastructure and amount of water stored at the time of the hazard incident. There are no dams located within the planning area; however, the Whittier Narrows Dam and Reservoir and Santiago Creek Dam have inundation zones that would potentially impact the City of Seal Beach. Additional information on the Whittier Narrows Dam and Reservoir and Santiago Creek Dam is listed in Table 5-7, Upstream Dams and Reservoirs affecting the City of Seal Beach. Refer to Figure 5-10, Dam Inundation Zones for an illustration of inundation extent within the City.

Levees are primarily located along the San Gabriel River adjacent to the City. The 20.54-mile San Gabriel River 1 (SGR1) Levee System is located in Los Angeles and Orange counties. SGR1 Levee System is made up of an earthen levee embankment and a trapezoidal channel. The riverward slope of the channel is covered with riprap, grouted stone, or reinforced concrete. The SGR1 Levee System protects residential, commercial, industrial, and civic improvements from flooding.64 Levees along the San Gabriel River near the City of Seal Beach reduce risk of flooding for the western portion of the City including Old Ranch, Rossmoor Center, College Park West, Leisure World, Marina Hill, Hellman Ranch, Boeing Facility, Old Town and Bridgeport.

Table 5-7
Upstream Dams and Reservoirs Affecting the City of Seal Beach Dam
Name
Dam
Owner Location Hazard Classification Type Size DSOD Rating Santiago
Creek
Dam
Serrano
Water
District
and Irvine
Ranch
Water
District
Inundation
zone
within the
City
Extremely
High
Earthen
Embankment
38,000
acre-feet
Poor
Whittier
Narrows
Dam and
Reservoir
U.S. Army
Corps of
Engineers
Inundation
zone
within the
City
DSAC I Earth 66,702.0
acre-feet
N/A*
*DSOD does not assign rankings for any dams owned/operated by USACE.

Sources: US Army Corps of Engineers, Dam Safety Mega Projects, https://www.spl.usace.army.mil/Missions/Mega-Projects/Dam-Safety-Mega-Projects/, accessed March 5, 2025; California Department of Water Resources, Division of Safety of Dams, Dams within Jurisdiction of the State of California, https://resources.ca.gov/-/media/DWR-Website/Web-Pages/Programs/AllPrograms/Division-of-Safety-of-Dams/Files/Publications/DAMS-WITHIN-JURISDICTION-OF-THE-STATEOF-CALIFORNIA-LISTED-ALPHABETICALLY-BY-COUNTY-SEPTEMBER-2023.pdf, published September 2023, accessed December 31, 2024.
64 US Army Corps of Engineers, San Gabriel River 1 Levee System, Los Angeles County, California, Periodic Inspection Report No. 2 Generalized Executive Summary,
https://www.spl.usace.army.mil/Portals/17/docs/LeveeSafetyProgram/San_Gabriel_River_1_Levee_Syste m_PI_Report_No_2_ES_U_20170419.pdf, submitted January 2017, accessed January 2, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.6.2 LOCATION/EXTENT
September 2025 Section 5. Coastal and Flooding Hazard Assessment Figure 5-10
Dam Inundation Zones
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Dam Inundation Zones
46 ,._
?,,,:,.-......_ I ~ -...

I 47....... I
I "'@ I
/ I
/ I
Long Beach
a,
tlfi - -,
Los Alamitos
W estminster
~
Seal Beach
Notional Wildlife Rel~e
Bolso Ave
66 ij)'
_68)
wor-_____ ,... ____ 2.,mnes -$
Section 5. Coastal and Flooding Hazard Assessment
Edinger Ave
Legend
r - ,
L - .I
Seal Beach
Municipal Boundary
Critical Facilities
Impacted Critical Facilities
Whittier Narrows Dam and
Reservoir Inundation Zone
Santiago Creek Dam
Inundation Zone
Source: CA Deportment of Water Resources_ U.S. Corps of A rmy Engineers, CA Division of Safety of Dams, CA SHMP, City of Seal Beach, Esri
Projection: California State Plane Coordinofe Sysfem Zone 6, NAD83
CASHMP 2023
September 2025
The Whittier Narrows Dam and Reservoir has a larger potential impact zone on the planning area if dam failure occurs at maximum capacity. This Reservoir is located in Los Angeles County, approximately 22 miles north of the City of Seal Beach. This Dam and Reservoir’s spillway has a DSAC of 1, representing an extremely high incremental risk due to the potential for significant loss of life and economic damages should failure of the dam occur.65 The San Gabriel River and Rio Hondo both flow into the Reservoir, bringing flows collected from a 554 square mile drainage reservoir.66 Construction of this dam was completed in October 1957 and is continuously monitored to ensure safety measures are maintained. The USACE recently published the Whittier Narrows Dam Flood Control Project Dam Safety Modification Study Final Environmental Impact Statement as of May 2019 to summarize and compare environmental impacts of dam risk management plans.
67 As a reservoir with an extremely high downstream hazard potential classification, the magnitude and extent of a failure would potentially be considerable.

The Santiago Creek Dam, also known as the Santiago Dam, is located on unincorporated land in Orange County, approximately 4 miles upstream from the City of Orange and north of the City of Irvine.68 The dam’s spillway is not considered a critical appurtenant structure (CAS) by DSOD but was included in DSOD’s 2017 list of spillways for re-evaluation. The drainage area upstream of the dam is 63.2 square miles. The Santiago Creek Dam forms the Irvine Lake which is filled by natural runoff during the rainy season.

The downstream hazard classification for the dam is extremely high and would potentially impact Anaheim Bay which acts as a deep-water Navy harbor at the bay entrance and Pacific Coast Highway. The Santiago Creek Dam was constructed between 1929 and 1931. As a reservoir with an extremely high downstream hazard potential classification, the magnitude and extent of a failure would potentially be considerable. This could lead to impacted evacuation efforts and transportation or water service disruptions during and after a dam or reservoir failure event.

In the event of an incident at Santiago Creek Dam, any field level response will coordinate with the Unified Command which includes Orange County Sherriff’s Department, Orange County Fire Authority, and representatives from IRWD and SWD, in addition to all agencies of downstream jurisdictions including Seal Beach. Actions would be carried out by the Seal Beach Police Department and Orange County Fire Authority. Responsibilities may include:
• Advising threatened populations of the emergency and informing them of safety measures to be implemented
• Dissemination of accurate and timely emergency public information and warning to the public
• Evacuation and rescue operations
65 US Army Corps of Engineers, Los Angeles District Website, Dam Safety Mega Projects, https://www.spl.usace.army.mil/Missions/Mega-Projects/Dam-Safety-Mega-Projects/, accessed March 5, 2025.
66 US Army Corps of Engineers, Los Angeles District Website, Whittier Narrows Dam, https://www.spl.usace.army.mil/Missions/Asset-Management/Whittier-Narrows-Dam/, accessed February 27, 2025.
67 US Army Corps of Engineers, Los Angeles County Drainage Area, Whittier Narrows Dam Flood Control Project Dam Safety Modification Study Final Environmental Impact Statement, published May 2019, accessed March 5, 2025.
68 Dam of the World, Santiago Creek Dam Quick Facts,
https://damsoftheworld.com/usa/california/santiago-creek-dam/, accessed December 31, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment • Establish evacuation routes and road closures
• Facilitate return of evacuate individuals
• Access and perimeter control
• Public health operations
• Restoration of vital services and utilities.

There have been no previous occurrences of dam or reservoir failure within the planning area.

However, major dam failures and recent crises in California include the Baldwin Hills Dam failure and the Orville Dam Crisis. On December 14, 1963, the Baldwin Hills Dam, located in the City of Los Angeles, suffered a catastrophic failure and flooded the surrounding residential areas. The sudden release resulted in five deaths and approximately $11 million in property damage.69 The incident triggered the State of California to update and implement dam safety standards, regulations, and inspection schedule. In the past 50 years, there have been few incidents in California as a result of these regulations.

The most recent major dam incident in California was the Oroville Dam Crisis in 2017.70 Erosion at the Oroville Dam emergency spillway threatened the structural integrity of the main weir and gate. Over 188,000 people were evacuated from downstream areas; however, emergency repairs ultimately prevented dam failure. The crisis served as a reminder of the ongoing risk presented by dams and initiated additional inundation mapping and emergency preparedness planning for California dams. Additionally, there are no previous occurrences involving levee failure in the City.

However, in 2017, the USACE identified several levees in the Los Angeles County area, including parts of the San Gabriel River levee system, that required maintenance and upgrades to ensure their reliability.

No federally or state declared disasters related to dam failure events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

The Irvine Ranch Water District provides emergency preparedness capabilities for a potential failure of the Santiago Creek Dam in coordination with the Orange County Sheriff’s Department (OCSD) and Orange County Fire Authority (OCFA). The USACE has been working on updating the Whittier Dam with the completion year for the Whittier Narrows Dam Project projected for 2031.71 Despite best planning efforts however, dam or reservoir failure resulting in flooding within the community could occur due to severe seismic activity. While the probability of future occurrences remains low, an incident has the potential to be destructive due to the urbanized nature of the City and the proximity to extremely high hazard dams and reservoirs. 69 Lessons Learned From Dam Incidents and Failures, Case Study: Baldwin Hills Dam (California, 1963), https://damfailures.org/case-study/baldwin-hills-dam/, published 2024, accessed January 2, 2025. 70 Vox, The crisis at Oroville Dam, explained, https://www.vox.com/science-andhealth/2017/2/13/14598042/oroville-dam-flood-evacuation, published February 15, 2017, accessed January 2, 2025.
71 Pico Rivera, Whittier Narrows Dam Update, https://www.pico-rivera.org/whittier-narrows-damupdate/, published March 27, 2023, accessed March 5, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.6.3 PREVIOUS OCCURRENCES

5.6.4 PROBABILITY OF FUTURE OCCURRENCES
Section 5. Coastal and Flooding Hazard Assessment September 2025 Given that the Santiago Creek Dam has a DSOD rating of “poor” and Whittier Narrows Dam and Reservoir has hazard classification of DSAC I, the LHMP planning team determined that the probability of dam/reservoir failure impacting the planning area in the future is considered highly likely. A highly likely probability means a nearly 100 percent probability in the next year, or it happens every year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that dam failure events will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team assigned a high hazard planning consideration to the hazards and impacts associated with dam reservoir failure based upon a highly likely probability and limited expected impacts of future events.

Climate change could indirectly increase the likelihood of dam/reservoir infrastructure and levee failure. Increased severe storm events and flooding incidents could increase strain on dam/reservoir infrastructure, including those dams near the City. This is evidenced by the 2017 Oroville Dam Crisis triggered by an unusually high influx of water from snowmelt and repetitive rain events.72 These inputs overwhelmed soil storage, leading to extreme runoff and resulting in erosion. Incidents such as this could increase “wear and tear” and require additional maintenance and infrastructure improvements to protect dam integrity and function. Severe storm events and increased temperatures resulting in rapid snowmelt both threaten to overwhelm dams/reservoirs. Severe storm events could also oversaturate soils and compromise dam infrastructure.

To identify populations at risk for mapped coastal and flooding hazards, hazard data layers were overlaid and compared with City parcel data in Geographic Information Systems, ArcGIS. If a hazard layer either completely or partially overlapped with a parcel in the data layer, then the entire parcel is conservatively considered vulnerable in this analysis. In some instances, the hazard zone intersected with only small portions of individual properties. However, to provide a detailed understanding of risk and vulnerability as part of this hazard mitigation plan, these parcels (including all residential and non-residential development on the parcel, regardless of location) are considered vulnerable.

Flood
Flood would potentially impact certain portions of the City of Seal Beach. Transportation is the primary asset type within the flood hazard zone; however, other types of critical facilities have also been identified as vulnerable. Critical facilities located within the flood hazard zone primarily include those that serve as safety and security, food, transportation, water systems, and communication community lifelines. In total, there are 28 vulnerable critical facilities located within the City’s flood hazard zone. Critical facilities located within the City’s identified flood hazard zone have been listed in Table 5-8, Critical Facilities in Flood Hazard Zone. 72 UC San Diego, Scripps Institute of Oceanography, Researchers Identify Factor Behind 2017 Oroville Dam Spillways Incident, https ://scripps.ucsd.edu/news/researchers-identify-factor-behind-2017-oroville-damspillways-incident, published July 22, 2020, accessed January 2, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.6.5 CLIMATE CHANGE CONSIDERATIONS

5.7 VULNERABILITY ASSESSMENT

5.7.1 MAPPED HAZARDS VULNERABILITY ASSESSMENT
September 2025 Section 5. Coastal and Flooding Hazard Assessment Approximately 399 residential units are located within the flood hazard zone. The number of vulnerable residential units multiplied by the average of 1.9 persons per household for Seal Beach indicates that approximately 758 people reside in the flood hazard zone. Additionally, approximately 283,803.38 square feet of non-residential structures are located within the flood hazard area. Refer to Table 5-9, Populations at Risk in Flood Hazard Zone for a summary of vulnerable residents, residential units, and non-residential buildings.

Table 5-8
Critical Facilities in Flood Hazard Zone
Map ID Name Asset Type
Community
Lifeline
Replacement
Value
4 Sewer lift pump station -
800 Ocean Ave
Water Systems Water Systems $1,050,000
6 Potable water well - 3333
Bolsa Chica Rd
Water Systems Water Systems $400,000
15 Seal Beach Marine Safety
Headquarters
Government
Services
Safety and
Security,
Communications
$3,129,060
16* OC-35 Import Waterline
Turnout
Transportation Transportation Not Available
17 Sewer lift station - 1st St Water Systems Water Systems $1,050,000 19 Bridge to Sunset Aquatic
Park (not City-owned)
Transportation Transportation Not Available
23 San Gabriel River Bike
Trail Entry Point
Transportation Transportation Not Available
26 Stormwater Pump Station
(County owned)
Water Systems Water Systems Not Available
27 Bridge 53C1998 - San
Gabriel River (Local)
Transportation Transportation $16,324,000
28 Bridge 55C0041L - Los
Alamitos Channel (Local)
Transportation Transportation $1,574,100
29 Bridge 55C0041R - Los
Alamitos Channel (Local)
Transportation Transportation $1,574,100
32 Bridge 55C0075 -
Westminster Channel
(Local)
Transportation Transportation $5,281,980
35 Bridge 55C0108 - Bolsa
Chica Channel (Local)
Transportation Transportation $5,888,300
36 Bridge 55C0160 - Bolsa
Chica Channel (Local)
Transportation Transportation $2,157,100
37 Bridge 53 0060 - San
Gabriel River (State)
Transportation Transportation $18,073,000
38 Bridge 53 0302L - San
Gabriel River (State)
Transportation Transportation $9,969,300
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 Map ID Name Asset Type
Community
Lifeline
Replacement
Value
39 Bridge 53 0302R - San
Gabriel River (State)
Transportation Transportation $9,969,300
40 Bridge 53 1185 - San
Gabriel River (State)
Transportation Transportation $35,563,000
41 Bridge 53 1737H - San
Gabriel River (State)
Transportation Transportation $7,287,500
42 Bridge 55 0010 - Anaheim
Bay (State)
Transportation Transportation $16,637,800
44 Bridge 55 0310 - Los
Alamitos Channel (State)
Transportation Transportation $9,328,000
45 Bridge 55 0334 - Bolsa
Chica Ditch (State)
Transportation Transportation $67,045,000
46 Bridge 55 0347H - Service
Rd (State)
Transportation Transportation $378,950
53 Bridge 55 0441 - Los
Alamitos Channel (State)
Transportation Transportation $15,158,000
54 Bridge 55 0471H - Los
Alamitos Channel (State)
Transportation Transportation $1,107,700
71 Seal Beach Ocean Pier Seal Beach
Ocean Pier
Public Park Not Available
87 College Park Drive Box
Culvert Bridge
Bridge Transportation Not Available
88 College Park Drive Bridge
over San Gabriel River
Bridge Transportation Not Available
Table 5-9
Populations at Risk for Flooding
Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
758 399 283,803.38
Other areas vulnerable to flooding include Anaheim Bay, Seal Beach National Wildlife Refuge, the Naval Weapons Station, and beach areas. Flooding could directly impact and cause secondary impacts along the coast of the City. Incidents of severe flooding could also impact the planning area, leading to the displacement of residents and the destruction of homes and businesses. The economic impact would include significant losses in property value, tourism, and local businesses.

Overall, the potential social, economic, and environmental consequences of flooding in the City could be far-reaching and may require investment in mitigation and adaptation strategies.

Sea-Level Rise and Coastal Erosion
Sea-level rise and coastal erosion may primarily impact those that serve as safety and security, food, hydration, shelter, and health and medical community lifelines. In total, there are 18 vulnerable critical facilities located within the City’s 2 ft sea level rise hazard zone and 45 critical facilities within the City’s 6 ft sea level rise hazard zone. Transportation, safety and security, water DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment u
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systems, and communications are the primary asset types within the sea level rise hazard zones.

However, other types of critical facilities have been identified as vulnerable. Critical facilities located within the City’s identified sea level rise hazard zones have been listed in Table 5-10, Critical Facilities in Sea level Rise Zone and Potential Coastal Erosion Zones.

There are 1,729 units located within the 2 ft sea level rise zone and 13,015 residential units located in the 6 ft sea level rise hazard zone. The number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that there are 3,285.1 individuals residing within the 2 ft sea level rise hazard zone and 13,015 people reside in the 6 ft sea level rise hazard zone. Additionally, approximately 461,128.7 square feet of non-residential structures are located within the 2 ft sea level rise zone and 4,226,960.9 residential units located in the 6 ft sea level rise zone. Refer to Table 5-11, Populations at Risk for Sea Level Rise, Coastal Erosion, and Coastal Storms for a summary of vulnerable residents, residential units, and non-residential buildings.

Table 5-10
Critical Facilities in Sea Level Rise, Coastal Erosion and Coastal Storms Hazard Zone Map
ID Name Asset Type Community Lifeline Replacement Value 2 ft Sea Level Rise Zone
17 Sewer lift station -
1st St
Water Systems Water Systems $1,050,000
19 Bridge to Sunset
Aquatic Park (not
City-owned)
Transportation Transportation Not Available
23 San Gabriel River
Bike Trail Entry
Point
Transportation Transportation Not Available
26 Stormwater Pump
Station (County
owned)
Water Systems Water Systems Not Available
27 Bridge 53C1998 -
San Gabriel River
(Local)
Transportation Transportation $16,324,000
28 Bridge 55C0041L
- Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
29 Bridge 55C0041R
- Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
30 Bridge 55C0042L
- Federal Storm
Channel (Local)
Transportation Transportation $1,690,700
31 Bridge 55C0042R
- Federal Storm
Channel (Local)
Transportation Transportation $1,906,410
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 Map
ID Name Asset Type Community Lifeline Replacement Value 37 Bridge 53 0060 -
San Gabriel River
(State)
Transportation Transportation $18,073,000
42 Bridge 55 0010 -
Anaheim Bay
(State)
Transportation Transportation $16,673,800
44 Bridge 55 0310 -
Los Alamitos
Channel (State)
Transportation Transportation $9,328,000
57 Leisure World
Clubhouse 2
Community Facility Safety and Security Not Available
60 Leisure World
Clubhouse 5
Community Facility Safety and Security Not Available
61 Leisure World
Clubhouse 6
Community Facility Safety and Security Not Available
62 Leisure World
Healthcare Center
Community Facility Safety and Security $3,000,695
71 Seal Beach Ocean
Pier
Public Park Safety and Security Not Available
87 College Park
Drive Box Culvert
Bridge
Bridge Transportation Not Available
6 ft Sea level Rise Zone
2 2901 Edinger Ave
- Sewer lift pump
station
Water Systems Water Systems $1,050,000
4 Sewer lift pump
station - 800
Ocean Ave
Water Systems Water Systems $1,050,000
8 Sewer lift pump
station - 200 Seal
Beach Blvd
Water Systems Water Systems $1,050,000
10 Sewer lift pump
station - 2701
Seal Beach Blvd
Water Systems Water Systems $1,050,000
11 43 ½ Riversea Rd
- Stormwater
pump station
Water Systems Water Systems $1,050,000
15 Seal Beach Marine
Safety
Headquarters
Government
Services
Safety and Security,
Communications
$3,129,060
17 Sewer lift station -
1st St
Water Systems Water Systems $1,050,000
18 Stormwater Pump
Station (County
owned) - 202 Seal
Beach Blvd
Water Systems Water Systems Not Available
19 Bridge to Sunset
Aquatic Park (not
City-owned)
Transportation Transportation Not Available
20 OC San Regional
Wastewater
Collections
Water Systems Water Systems Not Available
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment u
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Map
ID Name Asset Type Community Lifeline Replacement Value Station (not Cityowned)
22 OC San
Wastewater
Station - (3112
Yellowtail,
Rossmoor)
Water Systems Water Systems Not Available
23 San Gabriel River
Bike Trail Entry
Point
Transportation Transportation Not Available
24 Los Cerritos
Wetlands
Restoration (not
City-owned)
Wetlands Safety and security Not Available
25 Hellman Oil Field
(not City-owned)
Oil Field Hazardous Materials Not Available
26 Stormwater Pump
Station (County
owned)
Water Systems Water Systems Not Available
27 Bridge 53C1998 -
San Gabriel River
(Local)
Transportation Transportation $16,324,000
28 Bridge 55C0041L
- Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
29 Bridge 55C0041R
- Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
30 Bridge 55C0042L
- Federal Storm
Channel (Local)
Transportation Transportation $1,690,700
31 Bridge 55C0042R
- Federal Storm
Channel (Local)
Transportation Transportation $1,906,410
33 Bridge 55C0104 -
Federal Storm
Channel (Local)
Transportation Transportation $4,185,940
37 Bridge 53 0060 -
San Gabriel River
(State)
Transportation Transportation $18,073,000
38 Bridge 53 0302L -
San Gabriel River
(State)
Transportation Transportation $9,969,300
39 Bridge 53 0302R -
San Gabriel River
(State)
Transportation Transportation $9,969,300
42 Bridge 55 0010 -
Anaheim Bay
(State)
Transportation Transportation $16,673,800
43 Bridge 55 0065 -
Kitt Highway, US
Navy RR (State)
Transportation Transportation $6,879,400
City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 Map
ID Name Asset Type Community Lifeline Replacement Value 44 Bridge 55 0310 -
Los Alamitos
Channel (State)
Transportation Transportation $9,328,000
56 Leisure World
Clubhouse 1
Community Facility Safety and Security Not Available
57 Leisure World
Clubhouse 2
Community Facility Safety and Security Not Available
58 Leisure World
Clubhouse 3
Community Facility Safety and Security Not Available
59 Leisure World
Clubhouse 4
Community Facility Safety and Security Not Available
60 Leisure World
Clubhouse 5
Community Facility Safety and Security Not Available
61 Leisure World
Clubhouse 6
Community Facility Safety and Security Not Available
62 Leisure World
Healthcare Center
Healthcare Facility Health and Medical $3,000,695
63 Mary Wilson
Library
Community Facility Safety and Security,
Communications
$3,271,290
66 Seal Beach Senior
Center
Community Facility Safety and Security;
Food, Water, Shelter
$436,931
71 Seal Beach Ocean
Pier
Public Park Safety and Security Not Available
76 Corsair Park Public Park Safety and Security $150,000 77 Electric Avenue
Greenbelt
Public Park Safety and Security $3,950,000
78 Edison Park Public Park Safety and Security $5,000,000 82 Marina Park +
Community
Center
Public Park Safety and Security $500,000
83 Schooner Park Public Park Safety and Security $950,000 84 Zoeter Field Public Park Safety and Security $750,000 87 College Park
Drive Box Culvert
Bridge
Bridge Transportation Not Available
88 College Park
Drive Bridge over
San Gabriel River
Bridge Transportation Not Available
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment u
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Table 5-11
Populations at Risk for Sea Level Rise, Coastal Erosion, and Coastal Storms Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
2 ft Sea Level Rise Zone
3,285.1 1,729 461,128.723
6 ft Sea Level Rise Zone
13,015 6,850 4,226,960.947
Tsunami
Critical facilities located within the tsunami hazard zone primarily include those that serve as safety and security, water systems, transportation, and hazardous materials community lifelines.

In total, there are 33 vulnerable critical facilities located within the City’s tsunami hazard zone.

Transportation and safety and security are the primary asset types within the tsunami hazard zone, however other types of critical facilities have also been identified as vulnerable. Critical facilities located within the City’s identified tsunami hazard zone have been listed in Table 5-12, Critical Facilities in Tsunami Hazard Zone.

Approximately 3,577 residential units are located within the tsunami hazard zone. The number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that approximately 6,797 people reside in the tsunami hazard zone. Additionally, approximately 2,388,630.4 square feet of non-residential structures are located within the tsunami hazard area. Refer to Table 5-13, Populations at Risk for Tsunami for a summary of vulnerable residents, residential units, and non-residential buildings.

Table 5-12
Critical Facilities in Tsunami Hazard Zone
Map ID Name Asset Type
Community
Lifeline
Replacement
Value
2 2901 Edinger Ave -
Sewer lift pump station
Water Systems Water Systems $1,050,000
4 Sewer lift pump station
- 800 Ocean Ave
Water Systems Water Systems $1,050,000
8 Sewer lift pump station
- 200 Seal Beach Blvd
Water Systems Water Systems $1,050,000
11 43 ½ Riversea Rd -
Stormwater pump
station
Water Systems Water Systems $1,050,000
13 OCFA Fire Station 44 Government
Services
Safety and
Security,
Communicatio
ns
$1,630,720
15 Seal Beach Marine
Safety Headquarters
Government
Services
Safety and
Security,
$3,129,060
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 Map ID Name Asset Type
Community
Lifeline
Replacement
Value
Communicatio
ns
17 Sewer lift station - 1st St Water Systems Water Systems $1,050,000 18 Stormwater Pump
Station (County owned)
- 202 Seal Beach Blvd
Water Systems Water Systems Not Available
19 Bridge to Sunset
Aquatic Park (not Cityowned)
Transportation Transportation Not Available
23 San Gabriel River Bike
Trail Entry Point
Transportation Transportation Not Available
27 Bridge 53C1998 - San
Gabriel River (Local)
Transportation Transportation $16,324,000
32 Bridge 55C0075 -
Westminster Channel
(Local)
Transportation Transportation $5,281,980
37 Bridge 53 0060 - San
Gabriel River (State)
Transportation Transportation $18,073,000
38 Bridge 53 0302L - San
Gabriel River (State)
Transportation Transportation $9,969,300
39 Bridge 53 0302R - San
Gabriel River (State)
Transportation Transportation $9,969,300
40 Bridge 53 1185 - San
Gabriel River (State)
Transportation Transportation $35,563,000
41 Bridge 53 1737H - San
Gabriel River (State)
Transportation Transportation $7,287,500
42 Bridge 55 0010 -
Anaheim Bay (State)
Transportation Transportation $16,673,800
43 Bridge 55 0065 - Kitt
Highway, US Navy RR
(State)
Transportation Transportation $6,879,400
63 Mary Wilson Library Community
Facility
Safety and
Security,
Communicatio
ns; Food
Water, Shelter
$3,271,290
64 McGaugh School Community
Facility
Safety and
Security;
Communicatio
ns; Food,
Water, Shelter
$3,771,540
66 Seal Beach Senior
Center
Seal Beach
Senior Center
Community
Facility
$436,931
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment u
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Map ID Name Asset Type
Community
Lifeline
Replacement
Value
68 City Hall City Hall Government
Building
$5,120,280
70 Police substation Police
Substation
Municipal
Services
Not Available
71 Seal Beach Ocean Pier Public Park Safety and
Security
Not Available
76 Corsair Park Corsair Park Public Park $150,000
77 Electric Avenue
Greenbelt
Electric
Avenue
Greenbelt
Public Park $3,950,000
79 Eisenhower Park Eisenhower
Park
Public Park $700,000
82 Marina Park +
Community Center
Community
Facility
Safety and
Security
$500,000
83 Schooner Park Public Park Safety and
Security
$950,000
84 Zoeter Field Public Park Safety and
Security
$750,000
85 Beach Maintenance
yard
Government
Building
Hazardous
Materials
$4,064,100
88 College Park Drive
Bridge over San Gabriel
River
Bridge Transportation Not Available
Table 5-13
Populations at Risk for Tsunami
Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
6,797 3,577 2,388,630.4
Dam
Critical facilities located within the dam failure zones primarily include those that serve as safety and security, transportation, food, hydration, and shelter, and health and medical community lifelines. In total, there are 39 vulnerable critical facilities located within the City’s dam failure hazard zones. Transportation and safety and security community lifelines are the primary asset types within the dam failure hazard zones; however, other types of critical facilities have also been identified as vulnerable. Critical facilities located within the City’s identified dam failure hazard zones have been listed in Table 5-14, Critical Facilities in Dam Failure Hazard Zones.

Approximately 7,389 residential units are located within the dam failure hazard zone. The number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that approximately 14,039 people reside in the dam failure hazard zones.

Additionally, approximately 4,333,474.50 square feet of non-residential structures are located City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 within the dam failure hazard zones. Refer to Table 5-15, Populations at Risk for Dam/Reservoir Failure for a summary of vulnerable residents, residential units, and non-residential buildings.

Table 5-14
Critical Facilities in Dam Failure Hazard Zones
Map ID Name Asset Type Community
Lifeline
Replacement
Value
1 3101 ½ N Gate Rd
- Potable water
reservoir, well and
pump station.

Water Systems Water Systems $2,425,000
2 2901 Edinger Ave
- Sewer lift pump
station
Water Systems Water Systems $1,050,000
10 Sewer lift pump
station - 2701 Seal
Beach Blvd
Water Systems Water Systems $1,050,000
11 43 ½ Riversea Rd -
Stormwater pump
station
Water Systems Water Systems $1,050,000
14 OCFA Fire Station
48 Government
Services
Safety and Security,
Communications
$1,630,720
19 Bridge to Sunset
Aquatic Park (not
City-owned)
Transportation Transportation Not Available
20 OC San Regional
Wastewater
Collections Station
(not City-owned)
Water Systems Water Systems Not Available
21 Leisure World
Water Well
(inactive)
Water Systems Water Systems Not Available
22 OC San
Wastewater
Station - (3112
Yellowtail,
Rossmoor)
Water Systems Water Systems Not Available
24 Los Cerritos
Wetlands
Restoration (not
City-owned)
Wetlands Safety and security Not Available
27 Bridge 53C1998 -
San Gabriel River
(Local)
Transportation Transportation $16,324,000
28 Bridge 55C0041L -
Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
29 Bridge 55C0041R -
Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
30 Bridge 55C0042L -
Federal Storm
Channel (Local)
Transportation Transportation $1,690,700
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment Map ID Name Asset Type Community
Lifeline
Replacement
Value
31 Bridge 55C0042R -
Federal Storm
Channel (Local)
Transportation Transportation $1,906,410
33 Bridge 55C0104 -
Federal Storm
Channel (Local)
Transportation Transportation $4,185,940
42 Bridge 55 0010 -
Anaheim Bay
(State)
Transportation Transportation $16,673,800
44 Bridge 55 0310 -
Los Alamitos
Channel (State)
Transportation Transportation $9,328,000
46 Bridge 55 0347H -
Service Rd (State)
Transportation Transportation $378,950
47 Bridge 55 0412L -
Interstate 405
(State)
Transportation Transportation $19,822,000
48 Bridge 55 0412R -
Interstate 405
(State)
Transportation Transportation $11,660,000
49 Bridge 55 0413F -
Rte 405, 605,
CONN, RIV (State)
Transportation Transportation $44,891,000
50 Bridge 55 0415 -
E22 - N405
Connector Ramp
(State)
Transportation Transportation $131,175,000
51 Bridge 55 0426G -
S605 - S405
Connector (State)
Transportation Transportation $12,458,710
52 Bridge 55 0428G -
State Route 22
(State)
Transportation Transportation $26,818,000
53 Bridge 55 0441 -
Los Alamitos
Channel (State)
Transportation Transportation $15,158,000
54 Bridge 55 0471H -
Los Alamitos
Channel (State)
Transportation Transportation $1,107,700
56 Leisure World
Clubhouse 1
Community
Facility
Safety and Security Not Available
57 Leisure World
Clubhouse 2
Community
Facility
Safety and Security Not Available
58 Leisure World
Clubhouse 3
Community
Facility
Safety and Security Not Available
59 Leisure World
Clubhouse 4
Community
Facility
Safety and Security Not Available
60 Leisure World
Clubhouse 5
Community
Facility
Safety and Security Not Available
61 Leisure World
Clubhouse 6
Community
Facility
Safety and Security Not Available
City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 5. Coastal and Flooding Hazard Assessment September 2025 Map ID Name Asset Type Community
Lifeline
Replacement
Value
62 Leisure World
Healthcare Center
Community
Facility
Safety and Security $3,000,695
65 North Seal Beach
Community Center
Community
Facility
Safety and Security;
Food, Water, Shelter
$995,610
76 Corsair Park Public Park Safety and Security $150,000 78 Edison Park Public Park Safety and Security $5,000,000 83 Schooner Park Public Park Safety and Security $950,000 87 College Park Drive
Box Culvert Bridge
Bridge Transportation Not Available
Table 5-15
Populations at Risk for Dam/Reservoir Failure
Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
14,039 7,389 4,333,474.50
Coastal Storms
Although this hazard is not mapped, the LHMP planning team chose the 2 ft sea-level rise flooding scenario as the City’s coastal storm hazard zone to evaluate which critical facilities are vulnerable to coastal storms. This hazard may primarily impact those that serve as safety and security, food, hydration, shelter, and health and medical community lifelines. In total, there are 17 vulnerable critical facilities located within the City’s coastal storm zone. Transportation, safety and security, water systems, and communications are the primary asset types within the sea level rise hazard zones. However, other types of critical facilities have been identified as vulnerable. Critical facilities located within the City’s identified coastal storm hazard zones have been listed in Table 5-10.

There are 1,729 units located within the 2 ft sea level rise zone while the number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that no known persons reside in the 2 ft sea level rise zone. Approximately 461,128.7 square feet of non-residential structures are located within the 2 ft sea level rise zone. Refer to Table 5-11 for a summary of vulnerable residents, residential units, and non-residential buildings.

Coastal Flood
Similarly, although coastal flooding is not mapped, the LHMP planning team chose the 2 ft sealevel rise flooding as the City’s coastal flood hazard zone to evaluate which critical facilities are vulnerable to coastal flood. This hazard may primarily impact those that serve as safety and security, food, hydration, shelter, and health and medical community lifelines. In total, there are 5 vulnerable critical facilities located within the City’s coastal flood zone. Transportation, safety and security, water systems, and communications are the primary asset types within the 2 ft sea level rise hazard zone. However, other types of critical facilities have been identified as vulnerable.

Critical facilities located within the City’s identified coastal flood hazard zone have been listed in Table 5-10.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

5.7.2 NON-MAPPED HAZARD VULNERABILITY ASSESSMENT
September 2025 Section 5. Coastal and Flooding Hazard Assessment There are 1,729 units located within the 2 ft sea level rise zone while the number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that no known persons reside in the 2 ft sea level rise zone. Approximately 461,128.7 square feet of non-residential structures are located within the 2 ft sea level rise zone. Refer to Table 5-11 for a summary of vulnerable residents, residential units, and non-residential buildings.

Since the 2019 LHMP, development and land use has not substantially changed in the planning area. In the five years since the approval of the previous LHMP, only one significant housing development was identified in the City’s most recent 2021-2029 Housing Element: the construction of approximately thirty single family homes on a former Department of Water and Power (DWP) site at the intersection of Marina Drive and 1st Avenue. Other land use changes since the 2019 LHMP were limited in scope, such as the addition of ADUs, and/or lot line adjustments.

As these changes were minor in size and scale, vulnerability is not considered to have significantly changed in the past five years.

As development and land use in the planning area has not substantially changed since the 2019 LHMP, population trends have also remained relatively the same. United States Census Data reports a 2020 population of 25,232 and a 2023 population of 24,868, representing a 1.44 percent population decline. Generally, observed population decline in the planning area is associated with an overall aging population.

Looking forward, the City anticipates the majority of population growth would align with the 2021-2029 Housing Element, which proposes to accommodate the City’s Regional Housing Needs Allocation of 1,243 units largely at commercial sites which are proposed to be rezoned for mixed use. These areas may be impacted by flooding hazards, especially areas along the coastline areas of the City along with western and northern portions of the City. Based on anticipated growth and development, it is reasonable to assume that vulnerability to coastal and flooding hazards will increase over the 5-year planning period of this LHMP.

Section 3.7 includes a detailed determination of Socially Vulnerable Populations (SVPs) within the planning area and characteristics that make those populations more vulnerable to hazards. The SVPs include census tracts 995.09, 995.10, 995.02 and the Seal Beach Shores Mobile Home Park.

Only census tract 995.10 has areas of vulnerability in the event of a 0.1 percent chance flood.

Coastal storms and coastal floods do not have an impact on SVPs using the 2 ft sea level rise flooding model. However, sea level rise and coastal erosion at 6 feet may impact census tracts 995.10, 995.09, 995.02, and the Seal Beach Shores Mobile Home Park. A potential tsunami in a worst-case scenario may impact census tract 995.02 and the Seal Beach Mobile Home Park. Census tracts at risk of dam/reservoir failure in a worst-case scenario include census tracts 995.02, 995.09, 995.10 and Seal Beach Shores Mobile Home Park.

Additionally, SVPs and other high-risk individuals exist throughout the planning area and may be present within coastal and flooding hazard zones despite a census tract’s social vulnerability classification. Specific SVPs and high-risk individuals that may be present throughout the planning City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

5.7.3 CHANGES IN VULNERABILITY FROM PREVIOUS FIVE YEARS

5.7.4 CHANGES IN VULNERABILITY FOR FUTURE FIVE YEARS

5.8 SOCIALLY VULNERABLE POPULATIONS ASSESSMENT
Section 5. Coastal and Flooding Hazard Assessment September 2025 area and coastal and flooding hazard zones include unemployed individuals, elderly populations aged 65 and older, young populations under age 17, persons with disabilities, persons with high pollution burden, and tourists, seasonal visitors, and homeless populations. The primary concern for SVPs and other high-risk individuals in the City would be evacuation efforts and access to emergency services and supplies, as well as recovery.

Unemployed individuals may be more vulnerable to coastal and flooding hazards as they may be financially limited in resources to prepare for disasters, such as purchasing emergency supplies, securing adequate housing, or evacuating to safer areas with transportation. Additionally, unemployed individuals may have substandard housing or live in flood-prone areas, increasing their risk of exposure to flooding. These populations may not have resources to seek medical care following a coastal and flooding hazard. These social and economic disparities can further hinder their ability to recover, leaving them at greater risk of long-term displacement and financial hardship following a coastal and flooding hazard event.

Young populations under age 17 may be more vulnerable to the impacts of coastal and flooding hazards due to being more susceptible to injuries and illnesses as their bodies are still developing.

Younger children may also have limited mobility and awareness to evacuate in time during a disaster and may have a hard time withstanding the force of floodwaters. Younger populations rely heavily on adults for protection, care, and decision-making; thus if parents/guardians/caregivers are affected by a disaster, the child’s safety and well-being may be compromised. Additionally, flooding can lead to school closures and displacement, which may disrupt children’s education and social development.

Elderly populations aged 65 and older are more vulnerable to coastal and flooding hazard events.

Persons aged 65 or older often face several challenges when responding to an emergency, such as mobility challenges, health concerns, social isolation, barriers to transportation, and limited access to information or technology. In addition, there is often overlap between persons aged 65 or older and persons with a disability, as older adults experience increased prevalence of disabilities. This could include cognitive impairment, difficulties with independent living or hearing and vision problems. Lastly, this population may rely on caregivers for their well-being; thus, evacuation may be more difficult if this service is disrupted.

Similarly, persons with disabilities are highly vulnerable to coastal and flooding hazards due to mobility challenges, experiencing difficulty evacuating quickly, or navigating through floodwaters.

This population may have more underlying health conditions that can be exacerbated by the stress and demands of a flooding event. This population may face communication barriers as emergency alerts and information may be inaccessible due to limited communication mediums. Coastal and flooding hazards can damage or destroy essential assistive devices such as wheelchairs, hearing aids, communication devices, and other medical technology. Lastly, persons with disabilities may rely on caregiving services, which may be disrupted during a coastal and flooding hazard event, making it much harder to evacuate.

Persons exposed to areas with a high pollution burden are more vulnerable to coastal and flooding hazards due to a variety of factors. Coastal and flooding hazards can further exacerbate populations with high pollution burdens who are already exposed to high pollution levels and have DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 5. Coastal and Flooding Hazard Assessment u
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weakened respiratory and cardiovascular systems. Additionally, contaminated floodwaters can further increase their risk of illness. Communities with high pollution often face economic challenges, making it harder to prepare and recover from coastal and flooding hazard events.

Lastly, persons dwelling in areas with a high pollution burden may have older, less resilient infrastructure, increasing the likelihood of damage during flooding and ultimately leading to prolonged exposure to hazardous conditions.

Tourists, seasonal visitors, and homeless populations are particularly vulnerable during coastal and flooding hazard events due to their lack of familiarity with the area and lack of established support systems. They may not be aware of evacuation routes or local emergency procedures, making it difficult for them to respond quickly. Additionally, they might not have access to timely information about coastal and flooding hazards and the resources needed to cope with the aftermath. The City hosts multiple community events throughout the year and nearby Huntington Beach and Long Beach are expected to host sizeable events for the upcoming 2028 Olympic Games, indicating increased present and future vulnerability. These factors make SVPs throughout Seal Beach especially vulnerable to the impacts of coastal and flooding hazards.

Considerations for SVPs throughout the planning area were incorporated into the mitigation strategy in Section 11.0, Mitigation Strategy. Specifically, the LHMP Planning Team tailored Mitigation Actions P.1, P.8, 1.8, 5.4, and 5.9 to mitigate hazard impacts to SVPs including issues related to preparedness, evacuation, and access to emergency services.

City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 5. Coastal and Flooding Hazard Assessment September 2025

Drought is defined as a prolonged period of abnormally low rainfall, leading to a shortage of water. Drought may also be defined by factors other than rainfall, including vegetation conditions, agricultural productivity, soil moisture, water levels in reservoirs, and stream flow.

Droughts or water shortages are a gradual phenomenon, often occurring over multiyear periods and increasing with the length of dry conditions. When precipitation is less than normal for a period of time, the flow of streams and rivers declines, water levels in lakes and reservoirs fall, and the depth to water in wells increases. If dry weather persists and water supply problems develop, the dry period can become a drought. The term “drought” can have different meanings depending on how a water deficiency affects day to day activities.

Drought is a complex natural hazard, reflected in the following four common definitions:
• Agricultural – Agricultural drought is defined principally in terms of naturally occurring soil moisture deficiencies relative to water demands of plant life, usually arid crops.
• Hydrological – Hydrological drought is related to the effects of precipitation shortfalls on stream flows and reservoir, lake, and groundwater levels.
• Meteorological – Meteorological drought is defined solely on the degree of dryness, expressed as a departure of actual precipitation from an expected average or normal amount based on monthly, seasonal, or annual time scales.
• Regulatory (or socioeconomic) – Regulatory drought can occur when the availability of water is reduced due to imposition of regulatory restrictions on the diversion and export of water out of a watershed to another area.

SECTION 6: EXTREME WEATHER HAZARD

ASSESSMENT

6.1 DROUGHT

6.1.1 DESCRIPTION
Although climate is a primary contributor to hydrological drought, other factors such as changes in land use (i.e., deforestation), land degradation, and dam construction can affect the hydrological characteristics of a region. Because regions are geographically interconnected by natural systems, drought impacts may extend well beyond the borders of the precipitation-deficient area. Changes in land use upstream may alter hydrologic characteristics such as infiltration and runoff rates, resulting in more variable stream flow and a higher incidence of hydrologic drought downstream.

Land use changes can alter water shortage frequencies, even when no change in precipitation occurred.1 2
Droughts cause public health and safety impacts, as well as economic, environmental, and social impacts. Public health and safety impacts are primarily associated with catastrophic wildfire risks and drinking water shortage risks. Examples of other impacts include costs to homeowners due to loss of residential landscaping, degradation of urban environments due to loss of landscaping, agricultural land fallowing and associated job loss, degradation of fishery habitat, and tree mortality with damage to forest ecosystems. Drought conditions can also result in damage to older infrastructure that is located within dry soils with potential to break or crack. Dead or dying vegetation poses a risk to falling and damaging structures and infrastructure systems.

Drought also results in drier brush and an increase in the size and severity of wildfires. Dry brush becomes significantly more flammable and increases the rate of wildfire spread. Extended drought conditions can also create challenges in procuring adequate amounts of water to fight wildfires.

Further, water and wastewater infrastructure systems located within areas susceptible to wildfires are at greater risk of being impacted. Damage or failure to water and wastewater infrastructure systems can significantly reduce or even interrupt service to customers. For more on wildfire hazards, refer to Section 9.0, Wildfire and Urban Fire Hazard Assessment.

Droughts are widespread regional events that affect the entirety of the City of Seal Beach. The geographic extent of drought conditions would extend to every resident within the planning area.

Certain areas within the City may experience more severe drought impacts than others.

Drought severity and extent depends on numerous factors including duration, intensity, and geographic extent, as well as regional water supply demands by humans and vegetation. The magnitude of drought is usually measured by time and severity of the hydrologic deficit. The United States Drought Monitor provides weekly data identifying portions of the United States that are experiencing drought. The intensity of drought is categorized as one five classifications:
abnormally dry (D0), showing areas that may be going into or are coming out of drought, and four levels of drought: moderate (D1), severe (D2), extreme (D3), and exceptional (D4); refer to Table 6-1, Drought Severity Classification.
1 National Drought Mitigation Center, Drought Basics,
https://drought.unl.edu/Education/DroughtBasics.aspx, accessed December 26, 2024. 2 NOAA, Definition of Drought, https://www.ncdc.noaa.gov/monitoring-references/dyk/drought-definition, accessed December 26, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.1.2 LOCATION/EXTENT
Section 6. Extreme Weather Hazard Assessment September 2025 Table 6-1
Drought Severity Classification
Category
Downstream
Hazard Potential
Classification
Potential Downstream Impacts to Life and
Property
D0 Abnormally Dry Going into drought: short-term dryness slowing planting, growth of crops or pastures. Coming out
of drought: some lingering water deficits;
pastures or crops not fully recovered.

D1 Moderate Drought Some damage to crops, pastures; streams, reservoirs, or wells low, some water shortages
developing or imminent; voluntary water-use
restrictions requested.

D2 Severe Drought Crop or pasture losses likely; water shortages common; water restrictions imposed.

D3 Extreme Drought Major crop/pasture losses; widespread water shortages or restrictions.

D4 Exceptional
Drought
Exceptional and widespread crop/pasture losses;
shortages of water in reservoirs, streams, and
wells creating water emergencies.

Source: United States Drought Monitor, Drought Classification, https://droughtmonitor.unl.edu/About/AbouttheData/DroughtClassification.aspx, accessed December 26, 2024.

Figure 6-1, Drought Monitor Map, and Figure 6-2, Drought Statistics Table, identifies areas of drought by intensity. As of December 2024, the planning area has been identified as “Abnormally Dry (D0)”, but not subject to drought conditions according to the United States Drought Monitor.

The Drought Monitor is not a forecast but looks backward; providing a weekly assessment of drought conditions based on how much precipitation did or did not fall.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 6. Extreme Weather Hazard Assessment Figure 6-1
Drought Monitor Map
Figure 6-2
Drought Statistics Table
Source: U.S. Drought Monitor, California,
https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?CA, accessed December 26, 2024.

Historically, the City of Seal Beach and County of Orange have faced high susceptibility to the drought hazard. From June 2007 to December 2009, Orange County was classified by the National Drought Monitor as D3: Extreme Drought Conditions before gradually being downgraded to D0:

Abnormally Dry conditions in December 2009. A statewide drought declaration was issued by the Governor in June 2008 in response to these conditions.

The most severe drought on record began in 2012 and continued through 2017. On January 17, 2014, the Governor of California declared a State drought emergency, and on April 1, 2015, the Governor announced the first-ever mandatory 25% Statewide water use reduction. As part of this reduction effort, the state proposed a series of actions to help save water, increase enforcement to prevent wasteful water use, streamline the State’s drought response, and invest in new City of Seal Beach Local Hazard Mitigation Plan
California
-None 00-04
Current 2024-12·24 43.49 SE.~·1
L.lst Weck to Current 20241217 43.49 56.51
3 Months Ago to Current 2024-09-24 28.59 71.4"1
Start of C.Jlendar Vear to Current 202312 26 96.65 3.35 Start of Water Year to Current 2024-10-01 28.40 71.60
One Year Ago to Current 2023-12-26 96.65 3.35

6.1.3 PREVIOUS OCCURRENCES
Section 6. Extreme Weather Hazard Assessment

DRA DE,IBERA IVE
Home / California
Map released: Weds. December 25, 2D24
Data valid: December 24. 2024 at 7 a.m. EST
Intensity
None
DO (Abnormally Dry)
D1 (Moderate Drought)
D2 (Severe Drought)
• D3 (Extreme Drought)
• D4 (Exceptional Drought)
• No Data
Authors
united States and Puerto Rico Author(s):

Brad 1'!18~- NOAA/CPC
Pacific Islands and Virgin Islands Author(s):

Richard Heim, NOAA/NCEI
01-04 02-04
"16.72 5.7C
-
103
-

0.00 -
80 16.72 5.7C 1.03 0.00 80

10.67 0.08 0.00 0.00 82

0.00 0.00 0.00 0.00

10.67 0.08 0.00 0.00 82

0.00 0.00 0.00 0.00
September 2025
technologies that would make California more drought resilient. At the time of the announcement, the volume of Sierra Nevada snowpack was approximately 14% of normal. By the end of May 2014, all of California was in a condition of “extreme” or “exceptional” drought. At the same time, the volume of the Sierra Nevada snowpack had decreased to less than 10% of normal and water stored in Lake Oroville, the major reservoir for the State Water Project, was at 58% of normal.3 After a series of winter rains, the Governor issued an executive order in April 2017 ending the drought emergency in Southern California, including Orange County.

California saw drought conditions recur during 2020 and 2021. A proclamation of a State of Emergency was made by the Governor of California for Mendocino and Sonoma counties in April of 2021, and the proclamation was expanded during summer 2021 to include the majority of northern and central California.4 On October 19, 2021, the State of Emergency was again expanded, this time including Orange County.5 After two wet seasons in 2023 and 2024, the State of California no longer suffers from widespread drought and no active National Weather Service drought information statements are active in California.6 Figure 6-3, Historical Drought and Rain Cycles in California, shows the historical droughts that have occurred in California from 2000 through the present.

Figure 6-3
Historical Drought and Rain Cycles in California
Source: National Integrated Drought Information System, California, https://www.drought.gov/states/california#historical-conditions, accessed December 26,2024. 3 California Department of Water Resources, California’s Most Significant Droughts: Comparing Historical and Recent Conditions, https://cawaterlibrary.net/document/californias-most-significant-droughtscomparing-historical-and-recent-conditions-2/, February 2015, accessed April 29, 2025. 4 Office of Governor Gavin Newsom, Governor Newsom Expands Drought Emergency to Klamath River, Sacramento-San Joaquin Delta, and Tulare Lake Watershed Counties, https://www.gov.ca.gov/2021/05/10/governor-newsom-expands-drought-emergency-to-klamath-riversacramento-san-joaquin-delta-and-tulare-lake-watershed-counties/, published May 10, 2021, accessed December 26, 2024.
5 Office of Governor Gavin Newsom, Governor Newsom Expands Drought Emergency Statewide, Urges Californians to Redouble Water Conservation Efforts, https://www.gov.ca.gov/2021/10/19/governornewsom-expands-drought-emergency-statewide-urges-californians-to-redouble-water-conservationefforts/, accessed December 26, 2024. 6 Drought.gov, California,
https://www.drought.gov/states/california#:~:text=There%20are%20no%20active%20National%20Wea ther%20Service%20drought%20information%20statements%20for%20California., accessed December 26, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan 100%
90%
80%
"'
~ 70% .., ""
:ii 60% _J
c
~ 50%
.,
~ 40% 19
~ 30%
20%
10%
0%
September 2025 Section 6. Extreme Weather Hazard Assessment No federally or state declared disasters related to drought have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

California weather is classified by a typical dry and wet season. During the wet season, the state relies on heavy precipitation events to constitute the majority of the annual total rainfall, so the absence of any event can significantly impact water availability. Certain atmospheric circulation patterns define California’s temperature and precipitation extremes. Examining these patterns, researchers discovered that atmospheric conditions associated with extreme drought have become increasingly common in recent decades.7
The United States Seasonal Drought Outlook depicts large-scale trends based on United States Drought Monitor areas (intensities of D1 to D4), as shown in Figure 6-4, United States Seasonal Drought Outlook. The U.S. Seasonal Drought Outlook indicates no drought is likely to affect the City through March 2025.8
Impacts of future droughts can be mitigated through water conservation efforts and other waterwise management practices taken by water purveyors. Previous occurrences of drought prompted actions to examine water storage, distribution, management, conservation, and use policies more closely. Water purveyors drafted administrative drought actions and implemented mechanisms allowing for administrative consistency in water conservation and drought regulations.

Based on previous occurrences and climate trends in California, there is a highly likely probability of drought affecting the City in the future, meaning there is a near 100 percent probability that drought may occur in the next year or may happen every year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that drought events will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team designated a high hazard planning consideration for drought considering the likelihood of future events and historical occurrences.

Climate change is a phenomenon that will likely exacerbate drought hazards. According to the 2023 California State Hazard Mitigation Plan, climate change is expected to affect California’s water supply conditions over the long term.9 While the City of Seal Beach does not face significant 7 Stanford News, California drought patterns becoming more common, Stanford scientists say, https://news.stanford.edu/2016/04/01/drought-patterns-change-040116/, published April 1, 2016, accessed December 26, 2024.
8 NWS Climate Prediction Center, U.S Seasonal Drought Outlook, https://www.cpc.ncep.noaa.gov/products/expert_assessment/sdo_summary.php, accessed December 26, 2024.
9 Cal OES, 2023 California State Hazard Mitigation Plan, chromeextension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.caloes.ca.gov/wp-content/uploads/HazardMitigation/Documents/2023-California-SHMP_Volume-1_11.10.2023.pdf, accessed December 26, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.1.4 PROBABILITY OF FUTURE OCCURRENCES

6.1.5 CLIMATE CHANGE
Section 6. Extreme Weather Hazard Assessment September 2025 drought vulnerability at this time, the effects of climate change may increase the City’s overall vulnerability to the drought hazard through rising temperatures, reduced precipitation, and changes in ocean temperature.

Figure 6-4
United States Seasonal Drought Outlook
Source: National Weather Service Climate Prediction Center, U.S. Seasonal Drought Outlook, https://www.cpc.ncep.noaa.gov/products/expert_assessment/sdo_summary.php, accessed December 26, 2024.

Extreme heat conditions refer to temperatures that are significantly higher than average for a particular regional location and time of year. Extreme or excessive heat can be a combination of high heat and high humidity, leading to heat-related illness. The heat index, or the apparent temperature, is what the temperature feels like to the human body when relative humidity and air temperature are both considered. Relative humidity can significantly increase the heat index and DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan U.S. Seasonal Drought Outlook
Drought Tendency During the Valid Period
Valid for December 19, 2024 - March 31, 2025
Released December 19, 2024
Author:

Adam Allgood
NOANNWS/NCEP Climate Prediction Center
; e
~
";'~ c.=7,;u~
..:....~ ·~
Depicts large-scale trends based
on subjectively derived probabiUties
guided by short- and long-range
statistical and dynamical forecasts.

Use caution for applications that
can be affected by short llved events.
-Ongoing• drought areas are
based on the U.S. Oroughl Monitor
areas (intensities of 01 lo 04).

NOTE: The tan areas imply at least
a 1--category improvement in the
Drought Monitor intensity levels by
the end of the period. although
drought will remain. The green
areas imply drought removal by the
end of the period (DO or none).
■ Drought persists
Drought r~mains,
but improves
■ Drought removal like ly
Drought development likely
□ No drought
t> ..... •·_-__ ,,.,, __________ ., ..._ _________ _, ..._ _________ __, https://go.usa.gov/3eZ73

6.2 EXTREME HEAT

6.2.1 DESCRIPTION
September 2025 Section 6. Extreme Weather Hazard Assessment contribute to dangerous health conditions.10High heat and humidity can cause heat-related illness, including heat cramps, heat exhaustion, and heat stroke.11 Extreme heat is location specific and determined based on average temperature for a given location. While there is no universal definition for an extreme heat event, the 2023 California State Hazard Mitigation Plan (SHMP) defines extreme heat as temperatures that hover 10ºF or more above the average high temperatures for a region for several days or weeks.12 A heat wave is a period of abnormally hot weather generally lasting more than two days.13 The threat of extreme heat can be higher in urban areas, where dark-colored roofs and paving materials cause the air temperature to be hotter. The dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat is known as the urban heat island effect.14 Extreme heat can have a grave effect on the City’s urban forestry. This hazard can cause heat stress stunting tree growth, reduced photosynthesis, and increased water loss. Trees can also be more susceptible to pests and disease as trees are in a weakened state due to the heat. As extreme heat can raise soil temperatures, high soil temperature can affect root heath and function reducing their ability to absorb water and nutrients.15
The geographic extent of extreme heat conditions would extend to every resident within the planning area, and extreme heat events typically last for a few days. The National Weather Service (NWS) uses a heat index, or apparent temperature, to help identify extreme heat events and predict extent of potential impacts. The dangers of extreme heat increase with time and exposure, meaning that a prolonged period of extreme heat over just a few days can be particularly dangerous. Figure 6-5, Heat Index, shows the likelihood of heat disorder with prolonged exposure or strenuous activity associated with temperature and relative humidity.

The greatest risks from extreme heat events are health related. Although some heat-related illnesses are often minor and/or temporary such as heat rash, heat cramps, and heat exhaustion, extreme heat can overwhelm the body’s ability to maintain a safe internal temperature, causing a person’s body temperature to reach dangerous levels. If a person’s internal temperature rises to 10 National Weather Service, What is the Heat Index?,
https://www.weather.gov/ama/heatindex#:~:text=The%20heat%20index%2C%20also%20known,sweat %20to%20cool%20itself%20off., accessed December 30, 2024. 11 National Weather Service, Excessive Heat Conditions, https://www.weather.gov/phi/heatcond#Overview, accessed December 30, 2024.
12 Cal OES, 2023 California State Hazard Mitigation Plan, https://www.caloes.ca.gov/wpcontent/uploads/Hazard-Mitigation/Documents/2023-California-SHMP_Volume-1_11.10.2023.pdf, accessed December 30, 2024.
13 National Weather Service NOAA, During a Heat Wave, https://www.weather.gov/safety/heat-during, published 2024, accessed December 30, 2024.
14 US EPA, Reduce Urban Heat Island Effect, https://www.epa.gov/green-infrastructure/reduce-urban-heatislandeffect#:~:text=%22Urban%20heat%20islands%22%20occur%20when,heat%2Drelated%20illness%20an d%20mortality, accessed December 30, 2024.
15 PennState Extension, Heat Stress in Urban Trees, https://extension.psu.edu/heat-stress-in-urbantrees#:~:text=The%20approximate%20thermal%20death%20threshold,F%20to%2085%C2%B0F., updated March 7, 2024, accessed January 13, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.2.2 LOCATION/EXTENT
Section 6. Extreme Weather Hazard Assessment September 2025 104 degrees Fahrenheit or above, heatstroke can occur.16 Heatstroke can cause fainting, seizures, and mental impairment. If left untreated, it may lead to permanent organ damage, coma, or death.

Extreme heat is unlikely to result in physical damage to structures; however, residents may experience the effects of heat exhaustion or heat stroke. Additionally, the increased use of air conditioning may put stress on the power grid and lead to power outages. The National Weather Service (NWS) provides weather forecasts for jurisdictions out of the San Diego Weather Forecast Office which covers San Diego and Orange Counties. Anticipated extreme heat events would be reported by these weather stations, including specific anticipated duration and severity.

During extreme heat events, the City of Seal Beach opens the local Tennis Center as a public cooling center and may activate additional locations as needed. This facility is accessible to the public and allows service animals.

Figure 6-5
Heat Index
Source: National Weather Service, What is the Heat Index?, https://www.weather.gov/ama/heatindex#:~:text=The%20heat%20index%2C%20also%20 known,sweat%20to%20cool%20itself%20off., accessed December 30, 2024.

Extreme heat events have affected the City of Seal Beach during the summer months in previous years. Table 6-2, Extreme Heat Events in the City of Seal Beach from 2018 – 2024, identifies recent hazard events involving extreme heat have affected the planning area:

Table 6-2
Extreme Heat Events in the City of Seal Beach from 2018 – 2024 16 Mayo Clinic, Heat Exhaustion, https://www.mayoclinic.org/diseases-conditions/heatexhaustion/symptoms-causes/syc-20373250, accessed December 30, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan NWS Heat Index Temperature (°F)
40 45 80 82 84 87 89 100 1 - 81 83 85 88 91 103 1 c 50
>. 55 81 84 86 89 93 97 101 108 11 .'!:
"O 60 82 84 88 91 95 100 105 110 1 .E 65 82 85 89 93 98 103 ffl8 11 :::, J: 70 83 86 90 95 100 105 112 11 QI 75 84 88 92 97 103 108 11 .::
- 80 84 89 94 100 108 11 .!!!
QI
er:: 85 85 90 96 102 110 11
90 86 91 98 105 11
95 86 93 100 108 11
100 87 95 103 112 1
Likelihood of Heat Disorders with Prolonged Exposure or Strenuous Activity O Caution O Extreme Caution □ Danger ■ Extreme Danger

6.2.3 PREVIOUS OCCURRENCES
September 2025 Section 6. Extreme Weather Hazard Assessment ' I Date Description
July 2018 Extreme heat and dry conditions across Southern California.17 September 2019 Heat, high winds, and low relative humidity affects Southern California.18
October 2019 Gusty Santa Ana Winds, hot temperatures, and single-digit relative humidity across Orange County and Southern California.

August 2020 Long duration heat wave affects Orange County.

September 2020 Heat wave affected Los Angeles and Orange County breaking new heat records in cities such as Long Beach.

October 2020 Gusty Santa Ana Winds, high temperatures, and dense fog affected coastal areas of Orange County.

April 2021 A record-breaking heat wave affected Orange County.

June 2021 A long-lasting heat wave swept across Southern California, with isolated thunderstorms producing gusty winds.

August 2021 High temperatures affected the Orange County area from August 1-5, with dense fog affecting coastal communities.

September 2022 Early September heat wave.

July 2023 A long-duration heat event affected Orange County, leading to widespread heat-related incidents reported across the County.

September 2024 Heat wave hits Southern California.19
No federally or state declared disasters related to extreme heat events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Seal Beach has historically experienced extreme heat, especially within the past five years. There is highly likely probability of future extreme heat occurrences, meaning a 90 to 100 percent probability of occurrence in the next year or a recurrence interval of less than 1 year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that extreme heat will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team designated a high hazard planning consideration for extreme heat considering the likelihood for future extreme heat events. Extreme heat events will likely occur with a higher frequency and longer duration as climate change causes increased global temperatures.

Climate change is understood to have a direct impact on temperature. As global temperatures rise, there will be an increased occurrence and prolonged duration of extreme heat events. According to Risk Factor, a hot day in the City of Seal Beach is any day above a “feels like” temperature of 17 Meteoblue, Weather Archive Seal Beach,
https://www.meteoblue.com/en/weather/historyclimate/weatherarchive/seal-beach_unitedstates_5394086, accessed December 30, 2024. 18 Ibid
19 ABC7, Long Beach residents struggle without AC during SoCal heat wave, https://abc7.com/post/southern-california-heat-wave-brings-challenges-long-beach-residentsac/15271186/, published September 5, 2024, accessed December 30, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.2.4 PROBABILITY OF FUTURE OCCURRENCES

6.2.5 CLIMATE CHANGE
Section 6. Extreme Weather Hazard Assessment September 2025 86°F.20 The City of Seal Beach is expected to experience seven hot days this year, and in 30 years the frequency is expected to rise to 22 days above 86°F.

Heavy rains refer to events during which the amount of rainfall in a location substantially exceeds normal or typical rainfall conditions. Heavy precipitation is not necessarily an indicator that the total amount of precipitation has increased, rather that precipitation is occurring in more intense events. Changes in precipitation intensity, coupled with changes in the interval between events, can affect overall precipitation totals.21 Potential impacts of heavy rains include property damage, soil erosion, and increased flood risk (refer to Section 5.0, Coastal and Flooding Hazard Assessment), which in turn contribute to other hazards such as debris flows, flooding, and landslides (refer to Section 7.0, Landslide Hazard Assessment). The contribution of heavy rains to other hazards has the potential to cause significant property damage and loss of life within the planning area.

Heavy rains can also contribute to the mortality of an urban forest. This hazard can cause erosion and sediment movement, therefore exposing roots or burying them under excess soil causing the tree stress. Additionally, overly saturated soils prevent the tree from absorbing nutrients properly and root oxygen deprivation.22 Heavy rain can prolong wet conditions in a tree, promoting fungal infections such as root rot and other diseases. These infections can further weaken a tree, making trees more susceptible to other stresses.

The entirety of the planning area could be impacted by heavy rains. An indicator for the extent of a heavy rain season is the Oceanic Niño Index (ONI), used to monitor the El Niño-Southern Oscillation (ENSO). To calculate the ONI, scientists from the National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center calculate the average sea surface temperature in the El Niño 3.4 region (area of the east-central equatorial Pacific Ocean) for each month, and then average it with values from the previous and following months. The observed difference from the average temperature in that region, whether warmer or cooler, is the ONI value for that threemonth “season”. El Niño and La Niña conditions can affect climate conditions in southern California significantly. El Niño causes the Pacific jet stream to move south of the neutral position, often bringing increased precipitation and secondary impacts such as increased flooding. La Niña usually has the opposite effect and causes the Pacific jet stream to move northward. This usually leads to dry and drought-like conditions, along with warmer than normal temperatures during the winter. It is important to note that El Niño and La Niña are only predictors of precipitation in Southern California and may not always result in rainy or dry years. 20 Risk Factor, Does Seal Beach have Heat Risk?, https://firststreet.org/city/seal-beachca/670686_fsid/heat, accessed December 30, 2024. 21 US EPA, Climate Change Indicators: U.S. and Global Heavy Precipitation, https://www.epa.gov/climateindicators/climate-change-indicators-us-and-global-precipitation, accessed December 30, 2024. 22 UF ISAF Extension, We Had Plenty of Rain; Why Are My Trees Dying?, https://nwdistrict.ifas.ufl.edu/hort/2013/09/30/we-had-plenty-of-rain-why-are-my-trees-dying/, published September 30, 2013, accessed January 13, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan F
{
g, 6.3 HEAVY RAINS
• I
! 6.3.1 DESCRIPTION
"f

6.3.2 LOCATION/EXTENT
September 2025 Section 6. Extreme Weather Hazard Assessment Typically, municipal drainage infrastructure systems are designed to accommodate heavy rain events. During uncharacteristically heavy storms or rain events (such as those caused by an El Niño weather pattern), these drainage systems may not be sufficient to move stormwater flows and thus, result in flooding (see Section 5.0, Coastal and Flooding Hazard Assessment). Severe storms could also cause overtopping of dams or reservoirs or threaten slope stability (see Section

7.0, Landslide Hazard Assessment).

The City of Seal Beach typically receives an average rainfall of about 8.82 inches spread over approximately 57.8 days.23 The wetter seasons last approximately 4.3 months from November 2nd to March 30th.
24 The City typically sees the greatest amount of rainfall in February with an average of 5.5 rainy days.25 Incidents of heavy rainfall during storm events have the potential to affect the entirety of the planning area.

While heavy rains are not common, a few events in recent history have impacted the City. Table 6- 3, Heavy Rain Events in the City of Seal Beach from 2018 – 2024, identifies recent hazard events involving heavy rain that have affected the planning area. Additionally, College Park East has restrictive storm drain infrastructure exceeding a 5-year storm event which worsens flooding during heavy rain events. Thus, a subcommittee was formed as a result of the 2023-2024 winter for this area.

Table 6-3
Heavy Rain Events in the City of Seal Beach from 2018 – 2024 Date Description
January 2019 Heavy rains caused flooding in Seal Beach.26 July 2021 Monsoon rainstorms Seal Beach with flash flood watches and power outages.27
December 2021 Winter storm estimated to bring 3 inches of rain to the City. 28 September 2022 Tropical Storm Kay dropped heavy rains over the City. The parking lot of the Beach House restaurant was filled with 6 inches.29
23 Weather Atlas, Climate and monthly weather forecast Seal Beach, CA, https://www.weatheratlas.com/en/california-usa/seal-beach-climate, updated August 10, 2024, accessed December 30, 2024. 24 Weather Spark, Climate and Average Weather Year Round in Seal Beach, https://weatherspark.com/y/1657/Average-Weather-in-Seal-Beach-California-United-States-Year-Round, accessed December 30, 2024.
25 Ibid.
26 CBS, Heavy Rain Causes Major Flooding in Long Beach, Seal Beach, https://www.cbsnews.com/losangeles/news/flooding-long-beach-seal-beach/, published January 16, 2019, accessed January 7, 2025.
27 Patch, Monsoon Wakes Seal Beach: Flash Flood Watches, Power Outages, https://patch.com/california/losalamitos/monsoon-storm-seal-beach-flash-flood-watches-power-outages, posted July 26, 2021, accessed January 6, 2025.
28 Patch, Seal Beach, Los Alamitos Residents Prepare for Heavy, Wind & Flooding Tuesday, published December 13, 2021, accessed January 6, 2025.
29 Los Angeles Daily News, Kay, morphing from a tropical storm, pulls its punch: just minor flooding in some Southern California spots, https://www.dailynews.com/2022/09/10/tropical-storm-kay-brings-minorflooding-damage-to-southern-california/, published September 10, 2022, accessed January 6, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.3.3 PREVIOUS OCCURRENCES
Section 6. Extreme Weather Hazard Assessment September 2025 Date Description
December 2022 Heaps of debris flowed down San Gabriel River washing up on Seal Beach.30
February 2023 A storm brought heavy rain, strong winds, and high surf to the City.31
March 2023 Heavy rains storms cause flooding throughout Orange County region.32
August 2023 Tropical Storm Hilary brought significant rainfall to the area, with Seal Beach receiving around 2.92 inches of rain.33 February 2024 A heavy rainstorm led to significant flooding in Seal Beach, causing street closures and disruption to local businesses and residences.34
November 2024 College Park East experienced constant flooding as the area lacks stormwater drainage and expressed concerns for new development in Los Alamitos.
35 As a result of storm conditions
during the winters of 2023 and 2024, the Seal Beach Ad Hoc Street and Storm Drain Committee was formed.

Two federally declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• DR-4699-CA – Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides
• DR-4769-CA – Severe Winter Storms, Tornadoes, Flooding, Landslides, and Mudslides Additionally, five state declared disasters related to flooding from heavy rains impacted the planning area within the last five years:
• 136: Winter Storms, February 2024
• 142: Tropical Storm Hillary, August 2023
• 141: Severe Winter Storms, February 2023 to March 2023 • 140: Severe Winter Storms, December 2022 to January 2023 30 The Orange County Register, Junk litters Seal Beach after big rain washes train down San Gabriel River, https://www.ocregister.com/2022/12/13/first-flush-washes-trash-down-the-san-gabriel-river-straightto-the-ocean/, updated December 14, 2022, accessed January 6, 2025. 31 City of Seal Beach Press Release, Heavy Rain, Wind, Surf, and Cold Expected, https://www.sealbeachca.gov/Portals/0/Documents/NewsHighlights/City%20of%20Seal%20Beach%20P ress%20Release%20-%20Heavy%20Rain,%20Wind,%20Surf,%20and%20Cold%20Expected.pdf, released February 21, 2023, accessed January 6, 2025.
32 Patch, How Many Inches of Rain Fell in Seal Beach During Three-Day Storm?, https://patch.com/california/losalamitos/how-many-inches-rain-fell-seal-beach-during-three-day-storm, published March
33 Patch, Seal Beach Rainfall Totals from Tropical Storm Hilary: Cleanup Ensues, https://patch.com/california/losalamitos/seal-beach-rainfall-totals-tropical-storm-hilary-cleanup-ensues, published August 21, 2023, accessed January 6, 2025.
34 CBS News, Seal Beach businesses, residents cope with aftermath of flooding, https://www.cbsnews.com/losangeles/news/orange-county-sees-rain-during-storm/, updated February 2, 2024, accessed January 6, 2025.
35 ABC 7, Seal Beach residents fear housing development in nearby Los Alamitos will worsen flooding, https://abc7.com/post/seal-beach-residents-fear-housing-development-project-nearby-los-alamitos-willworsen-flooding/15561180/, published November 21, 2024, accessed June 10, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 6. Extreme Weather Hazard Assessment • 127: December Winter Storms, December 2021
Refer to Table 4-4, Summary of Declared Disasters Affecting the Planning Area for further details.

Based on previous occurrences and the seasonal climate of the area, there is a likely probability of future heavy rain impacts in the future. A likely probability means there is 10 to 100 percent probability in the next year or a recurrence interval of 10 years or less. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that heavy rain events will likely affect the planning area in the future and therefore felt “likely” best defined probability for this specific hazard. The LHMP planning team assigned a high hazard planning consideration to the hazards and impacts associated with heavy rain events based upon a likely probability and limited impacts of future events.

Climate change will affect the frequency and intensity of heavy rain events, causing secondary impacts such as flooding. As global temperatures increase, the average amount of moisture in the air will increase. This in turn leads to more severe storms including increased precipitation that ultimately leads to heavy rain events and associated hazards. Climate change is expected to exacerbate the impacts of severe storm-related impacts including incidents of heavy rain in the planning area.

According to the National Weather Service (NWS), Santa Ana Winds occur when air from a region of high pressure over the dry, desert region of the southwestern U.S. flows westward towards low pressure located off the California coast.36 This creates dry winds that flow east to west through the mountain passages in Southern California. These winds are most common during the cooler months of the year, occurring from September through May. Santa Ana winds typically feel warm (or even hot) because as the cool desert air moves down the side of the mountain, it is compressed, which causes the temperature of the air to rise. These strong winds can cause major property damage and increase wildfire risk because of the dryness of the winds and the speed at which they can spread a flame across the landscape.

Severe incidents of Santa Ana Winds may pose a significant risk to life and property by creating conditions that disrupt essential systems such as public utilities, telecommunications, and transportation routes. Destructive impacts to trees, power lines, and utility services also are associated with high winds. Falling trees can occasionally cause fatalities and serious structural damage and fallen power lines could cause widespread power outages and fire. 36 National Weather Service, Mountain and Valley Winds, https://www.weather.gov/safety/wind-mountainvalley, accessed December 30, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.3.4 PROBABILITY OF FUTURE OCCURRENCES

6.3.5 CLIMATE CHANGE

6.4 SANTA ANA WINDS AND TORNADOES

6.4.1 DESCRIPTION
Section 6. Extreme Weather Hazard Assessment September 2025 Tornadoes are rapidly rotating columns of air with circulation reaching the ground; they nearly always start as a funnel cloud and may be accompanied by a loud roaring noise.37 Tornadoes that form over water are called waterspouts. Waterspouts fall into two categories: fair weather waterspouts and tornadic waterspouts. Fair waterspouts usually form along the dark flat base of a line of developing cumulus cloud and are generally formed in light wind conditions, so they only move minimally.
38 Tornadic waterspouts are tornadoes that form over water or move from land to water and have the same characteristics as a land tornado.39 Tornadic waterspouts are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning.

Although many trees need wind for strengthening their structure, root development, and seed and pollen dispersal, high winds may cause severe damage to a tree. Strong winds can cause branches and limbs to break or split, especially in trees with brittle wood. This hazard can also uproot trees, causing trees to fall or strip leaves from the canopy, reducing the tree’s ability to photosynthesize.

Winds can damage the tree’s vascular system which is responsible for transporting water and nutrients.

Wind events such as the Santa Ana Winds typically impact large areas and can potentially impact any region of the planning area. Depending on the conditions of the wind event, impacts could be widespread or localized. The City of Seal Beach experiences seasonal variation in average wind speed, with the windiest parts of the year (November to May) yielding an average wind speed of

6.6 mph.40 The windiest month of the year tends to be December, with an average hourly speed of

8.0 miles per hour.41
During a severe wind event, the Santa Ana Winds can reach a wind speed of up to 115 mph.42 Santa Ana Wind events can result in damaged buildings and infrastructure, damaging personal property including vehicles and homes. Downed trees, damaged power lines, and power outages may also affect residents within the City of Seal Beach. Table 6-4, Beaufort Wind Scale, relates wind speed to observed conditions and is used to measure the intensity of wind events up to 74 miles per hour.

Table 6-4
Beaufort Wind Scale
37 NOAA, NOAA’s National Service Weather - Glossary,
https://forecast.weather.gov/glossary.php?word=tornado, accessed January 6, 2025. 38 Rochester, Waterspouts defined: Aren’t they just tornadoes on water?, https://www.rochesterfirst.com/weather/waterspouts-defined-arent-they-just-tornadoes-on-water/, published October 13, 2024, accessed January 6, 2025.
39 NOAA, What is a waterspout?, https://oceanservice.noaa.gov/facts/waterspout.html, last updated June 16, 2024, accessed January 6, 2025.
40 Weather Spark, Climate and Average Weather Year Round In Seal Beach, https://weatherspark.com/y/1657/Average-Weather-in-Seal-Beach-California-United-States-Year-Round, accessed December 30, 2024.
41 Ibid.
42 Rancho Santiago Community College District, Section IV-F – Severe Weather/Santa Ana Winds, https://www.rsccd.edu/Departments/Risk-Management/Documents/Risk%20Management/IVF%20Windstorms.pdf, accessed December 30, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

6.4.2 LOCATION/EXTENT
September 2025 Section 6. Extreme Weather Hazard Assessment Beaufort Scale Wind Speed Description
0: Calm Less than 1
mph
Smoke rises vertically.
1: Light air 1 to 3 mph Direction shown by smoke drift but not by wind vanes. 2: Light breeze 4 to 7 mph Wind felt on face; leaves rustle; wind vane moved by wind.
3: Gentle
breeze
8 to 12 mph Leaves and small twigs in constant motion; light flags extended.
4: Moderate
breeze
13 to 18 mph Raises dust and loose paper; small branches moved. 5: Fresh
breeze
19 to 24 mph Small trees in leaf begin to sway; crested wavelets form on inland waters.
6: Strong
breeze
25 to 31 mph Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty.
7: Near gale 32 to 38 mph Whole trees in motion; inconvenience felt when walking against the wind.
8: Gale 39 to 46 mph Twigs break off trees; generally impedes progress. 9: Strong gale 47 to 54 mph Slight structural damage (chimney pots and slates removed).
10: Storm 55 to 63 mph Seldom experienced inland; trees uprooted; considerable structural damage.
11: Violent
storm
64 to 72 mph Very rarely experienced; accompanied by widespread damage.
12: Hurricane 73 mph and
above
Devastation.

Source: National Weather Service, Beaufort Wind Scale, https://www.weather.gov/mfl/beaufort, accessed December 30, 2024.

The specific magnitude, severity, and actual impacts from wind events in the City can vary greatly depending on sustained windspeed and event duration. Though tornadoes are rare in the City of Seal Beach, the City is ranked as #30 on the Tornado Index relative to cities in California.43 Although rare, tornadic waterspouts and fair-weather waterspouts are possible in the City’s coastline.

The City of Seal Beach is relatively flat with an average elevation of about 13 feet above sea level, and the Santa Ana Winds can significantly increase in speed to reach 20 – 30 mph or higher in the City. Wind events specifically related to the Santa Ana winds are likely to peak between the months of September to December. Table 6-5, Santa Ana/High Wind Events in the City of Seal Beach from 2018 – 2024, identifies recent hazard events involving the Santa Ana Winds or other notable high wind events have affected the planning area:
43 USA.com, Seal Beach, CA Natural Disasters and Weather Extremes, http://www.usa.com/seal-beach-canatural-disasters-extremes.htm, accessed January 6, 2025.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.4.3 PREVIOUS OCCURRENCES
Section 6. Extreme Weather Hazard Assessment September 2025 Table 6-5
Santa Ana/High Wind Events in the City of Seal Beach from 2018 – 2024 Date Description
October 25, 2019 Orange County saw wind gusts up ranging from 35-49 miles per hour.44
December 3, 2020 Orange County saw wind speeds ranging from 40-79 mph.45 December 24, 2021 After an atmospheric river impacted Southern California, strong wind gusts impacted communities across coastal Orange County.

January 27, 2022 Wind advisory in Orange County including the City of Seal Beach.46
February 21, 2023 Strong winds impacted the Orange County Coastline.47 March 13, 2024 Strong Santa Ana Winds impacted coastal portions of Orange County. Peak wind gusts reached 20-40mph.

August 18, 2023 Hurricane Hilary increased high winds throughout Southern California.

November 6, 2024 Santa Ana wind conditions impacted much of Southern California.48
December 9, 2024 Red flag warning issues for Southern California with strong winds and dangers for fire, however coastline reaching up to 30 mph.49 January 7, 2025 Southern California faced a major Santa Ana windstorm with gusts of 50-70 mph forecasted.50 This windstorm lasted several days.

One federally declared disaster related to notable high wind events have impacted the planning area within the last five years:
• DR-4699-CA – Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides
44 Patch, Wind Speeds in Orange County: How Windy Was It?, https://patch.com/california/orangecounty/wind-speeds-orange-county-how-windy-was-it, published October 25, 2019, accessed January 7, 2025.
45 Patch, Orange County Santa Ana Wind Speeds Calculated, https://patch.com/california/orangecounty/orange-county-santa-ana-wind-speeds-calculated, published December 3, 2020, accessed January 7, 2025.
46 Patch, 30 mph Winds in Seal Beach and Los Alamitos, Wind Advisory in OC, https://patch.com/california/losalamitos/30-mph-winds-seal-beach-los-alamitos-wind-advisory-oc, published January 27, 2024, accessed December 30, 2024. 47 CBS News, Winter storm: Heavy wind, snow in Southern California, https://www.cbsnews.com/losangeles/live-updates/winter-storm-heavy-wind-rain-and-snow-insouthern-california/, published February 25, 2023, accessed December 31, 2024. 48Los Angeles Daily News, Dangerous Santa Ana winds batter Southern California, boosting fire danger, https://www.dailynews.com/2024/11/06/dangerous-santa-ana-winds-batter-southern-californiaboosting-fire-danger/, published November 6, 2024, accessed December 30, 2024. 49 Orange County Register, Red flag warning issued for Southern California, with strong winds, fire dangers foreseen, https://www.ocregister.com/2024/12/06/southern-california-fire-danger-rising-due-to-warmdry-santa-ana-winds/, updated December 9, 2024, December 30, 2024. 50 Newsweek, Santa Ana Winds: What’s Causing California’s ‘Life Threatening Storm’?, https://www.newsweek.com/santa-ana-winds-california-what-causing-life-threatening-storm-2010819, published January 7, 2025, accessed January 7, 2025.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 6. Extreme Weather Hazard Assessment For additional information on federal disaster declarations impacting the planning area, refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Santa Ana Wind events are probable events each year within the City of Seal Beach, with historical occurrences of Santa Ana Wind events indicating a likelihood for future events. High winds can exacerbate the risk of significant wildfires, making wind events of particular concern for the future.

There is a highly likely probability of future occurrences, meaning a 90 to 100 percent probability of occurrence in the next year or a recurrence interval of less than 1 year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that Santa Ana wind events will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team designated a high hazard planning consideration for Santa Ana Wind events after considering the future probability and potential impacts to interrupt communication lines, exacerbate wildfire, and result in power outages.

It is anticipated that wind patterns and development may be altered due to climate change. The resulting change is expected to cause an increase in the number of intense storms, which could in turn lead to an increase in the frequency of strong wind events such as Santa Ana Wind events.

According to the Southwest Climate Adaptation Science Center, climate change is expected to lead to overall decreases in Santa Ana Wind events during the early fall and late spring of each year.51 This projection describes decreases in frequency during these months, rather than decreasing intensity of the wind events. The peak of the Santa Ana Wind season (November through January) is expected to be least affected by climate change according to climate projections.

Power outages are a major secondary effect of severe weather events in the City. An outage could result in damaged power equipment or equipment failures and can affect multiple jurisdictions for hours. This type of event can range from a moderate event to a catastrophic regional event that may threaten human life, safety, and health, or interfere with vital services.

During severe weather incidents such as high winds, extreme heat, or severe flooding, Southern California Edison (SCE) may implement an operational practice called Public Safety Power Shutoffs (PSPS) to preemptively shut off power in high-risk areas during potentially dangerous 51 University of Arizona, Climate Change Suppresses Santa Ana Winds of Southern California and Sharpens Their Seasonality, https://swcasc.arizona.edu/publication/climate-change-suppresses-santa-ana-windssouthern-california-and-sharpenstheir#:~:text=Climate%20Change%20Suppresses%20Santa%20Ana%20Winds%20of%20Southern%20Ca lifornia%20and%20Sharpens%20Their%20Seasonality,-
Reference&text=We%20downscale%20Santa%20Ana%20winds,climatology%20over%20the%20historica l%20period., published 2019, accessed July 9, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

6.4.4 PROBABILITY OF FUTURE OCCURRENCES

6.4.5 CLIMATE CHANGE

6.5 PUBLIC SAFETY POWER SHUTOFF (PSPS)

6.5.1 DESCRIPTION
Section 6. Extreme Weather Hazard Assessment September 2025 conditions. This program is designed to proactively prevent SCE facilities from starting a wildfire in at-risk areas when winds and temperatures are high.

Strong Santa Ana winds, high temperatures, and low humidity are all severe weather conditions that could trigger a PSPS event. It is possible for extreme weather incidents outside of the City to trigger a PSPS that affects the service area (i.e., strong winds affecting regional infrastructure that powers SCE). The frequency of these events depends on the weather and environmental factors, and SCE makes decisions based on internal threat thresholds, assessment of real-time information, and situational awareness data. When possible, SCE intends to notify customers prior to a PSPS event. When weather forecasts indicate extreme fire conditions, SCE begins predictive modeling to assess the potential impacts while monitoring weather watch alerts from the National Weather Service. Three days prior to the forecasted PSPS, SCE would coordinate first with local governments, the emergency management community, first responders, and other critical infrastructure/service providers. Two days prior to the forecasted PSPS, notices would go out to SCE customers with a follow-up one day before the notice of power shutoff. It is noted that actual or sudden onset of extreme weather conditions could impact the intended coordination and notification efforts.52
Outside of the PSPS events, there is the potential for unplanned power outages to occur within Seal Beach. SCE defines a major outage as a large, unexpected outage caused by either accidents or natural disasters. While uncommon, loss of electrical power is a potential secondary effect of heavy rains or strong winds. Other types of events that could occur include mechanical power failure due to aging equipment.

The entirety of the planning area could be impacted by PSPS events. While PSPS events often target wildland areas with high wildfire risk, wider regions could be impacted. The targeted area is the area at risk due to weather conditions, especially during severe storm events in the planning area.

Given the long, connected nature of power supply systems, a shutoff event targeted at a small atrisk zone can affect power in larger, neighboring areas.

SCE designates High Fire Risk Areas as areas with circuits within California Public Utilities Commission’s (CPUC) Tier 2 (elevated risk) and Tier 3 (extreme risk) Fire Threat Areas. The CPUC Fire-Threat Map was developed with input from the U.S. Forest Service, California Department of Forestry and Fire Protection, and the State’s investor-owned utilities, including SCE. SCE uses their own thresholds prior to initiating a PSPS event. When evaluating weather and environmental conditions, SCE considers a variety of factors which include but are not limited to:
• National Weather Service Red Flag Warnings
• SCE meteorological assessments
• SCE Fire Potential Index
• SCE Fire Scientist assessments
• Real-time situational awareness information
• SCE Fire Management/Office of Emergency Management input 52 Southern California Edison, Public Safety Power Shutoff, https://www.sce.com/wildfire/psps, accessed December 30, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

6.5.2 LOCATION/EXTENT
September 2025 Section 6. Extreme Weather Hazard Assessment ' I • Concerns from local or State fire authorities
• Mandatory or voluntary evacuation orders in place
• Expected impact of de-energizing circuits on essential services (including public safety agencies, water pumps, traffic controls, etc.)
• Other operational considerations to minimize wildfire ignitions.

The magnitude or extent of impacts to the City would depend on the duration of the outage and the size of the impacted area.

Figure 6-6
CPUC Fire-Threat Map
Note: Red circle indicates the approximate location of the City of Seal Beach.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE 0 State of California - Public Utilities Commission
0 25 50 100 Miles
'
CPUC Fire-Threat Map
Adopted by the california Public Utilities Commission
(Revised on August 19, 2021)
The data portrayed In tht CPUC Are-llweat Map wee de¥eloped under RtAemaldno 15-05-006, folowtng procedures; In Ded:5lcn (D.) 17-0t-oo9, R!Vlsed by D.17-06-024, which~ a wcs1i: plil, fat the ~ d a utily High F~llweat District (HFTD) b' appicat10n ol enM'ICed ftt salefy ~ In ac:c:ordira wttl tht ~ 1hC!! HFTD Hap Isa mnposlte c:I two map pnxlLas. One d those map products IS hS CPUC A-e-1lweal Map. The CPUC FR-Tlreet Map dePl(tSareaswhereenhanctd I've S1lh:tt rt9J~ b..-.d inDeosion 17·t2-o24 wil appt,y. lhefinal CJIUC Fire 1lnM Map w-,s sobmitted to the Comm,ssion rill a 11er t Jtdva letter that was adopted by the Comnvssion's safety and En~ OWISOI (SEO) wth a dispositioi'I letter m J¥wry 19, 2018. Sli>sequentty, the final CPUC Are llweat Kap has been modi:fied by the Commission. All data and lnbmaCtcn portrayed m the CPUC Fft-Threal Map .w1! fa' the eqftSSftt u~ call!d aut In D.17·12-024. N'ff other ll2 d thC5 map 15 not the resp:nsibllty cl nor ffldorwd by the Co1Mw.s1on o, Its~ ll'ldepend!nt ~ Team.

Fire-Threat Areas
- Tier 3 - Extreme
Tier 2 - Elevated
G1 County
a , , • 1• , , 1, ? ' , • • '( ~-, •, < ' •• 1' • • • I ~, ••fr .,,,.,, , 1 • , ~ • ~ w • • i•• •' .-, • .w !• 1 ), ,, '" ' •• •• 1 , , >'• • ,. , , t • •'T • •.-, !'< 1 t f 1 • • 1' t, ._, 1 • , 'i•L •·...., • f , I ,.
,., ,, .. ,.... • .i_) • l • .. t• .,..,, •• I •" 1 1•~••.- .! '• • • ..- '"-f••;l t" ,.~ Section 6. Extreme Weather Hazard Assessment September 2025 At this time, the City of Seal Beach does not have a history of PSPS events. Overall, short-term power losses have primarily occurred as isolated incidents, without major impacts to the City. No federally or state declared disasters leading to PSPS have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Based on previous occurrences, there is a highly likely probability of future PSPS events in the future. A highly likely probability means there is a nearly 100 percent probability of occurrence in the next year or a recurrence interval of nearly every year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that PSPS events will likely affect the planning area in the future and therefore felt “highly likely” best defined probability for this specific hazard. The LHMP planning team assigned a medium hazard planning consideration to the hazards and impacts associated with PSPS events based upon a highly likely probability and limited primary impacts of future events.

As the effects of climate change continue to be observed, PSPS events are expected to increase as hazard events continue to be exasperated due to the effects of climate change. In recent years, PSPS events have been increasingly utilized in California as climate change, wildfire fuel accumulation, and expanded development of fire-prone lands increase the risk of wildfire events.53 In the event of a severe storm event, a PSPS may be deployed if electrical infrastructure is damaged to reduce the risk of damage to life and property within the City. An example of this would be high winds causing downed power lines that threaten the safety of local residents.

Drought
Drought conditions would affect the entirety of the City, and therefore all City critical facilities, infrastructure systems, structures, residents, and businesses are considered vulnerable to the drought hazard. Droughts do not typically result in physical damage to buildings and infrastructure, thus critical facilities are not at risk of destruction or structural failure. Instead, drought could potentially limit the availability of water supplies to City residents and businesses.

Concerns with limited water supplies may affect City firefighters’ ability to fight wildfire effectively. Furthermore, drought often coincides with the wildfire season and contributes to conditions conducive to wildfire, causing wildfire smoke and possible urban fires. 53 Wong-Parodi, Gabrielle, Support for public safety power shutoffs in California: Wildfire-related perceived exposure and negative outcomes, prior and current health, risk appraisal and worry, https://www.sciencedirect.com/science/article/abs/pii/S2214629622000032#:~:text=In%20recent%20 years%2C%20Public%20Safety,development%20in%20fire%20prone%20lands., published June 2022, accessed December 30, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

6.5.3 PREVIOUS OCCURRENCES

6.5.4 PROBABILITY OF FUTURE OCCURRENCES

6.5.5 CLIMATE CHANGE

6.6 VULNERABILITY ASSESSMENT

6.6.1 HAZARD VULNERABILITY ASSESSMENT
September 2025 Section 6. Extreme Weather Hazard Assessment Other effects of drought could be sustained by parks, landscaping, and grounds around commercial and residential facilities, as well as by various plant and animal species, which depend on a delicate meteorological balance to survive. The risk of damage to landscaping and the natural ecosystem, and potential economic impacts from increased water prices or an insufficient supply of water are concerns in addition to the effects of drought on exacerbating wildfire and consequently wildfire smoke conditions.

Extreme Heat, Heavy Rains, Santa Ana Winds and Tornadoes, PSPS Extreme weather events within the City of Seal Beach may include extreme heat, heavy rains, Santa Ana winds and tornadoes, and Public Safety Power Shutoffs (PSPS) as a measure to protect life and property. These extreme weather events could impact the entire City; therefore, all critical facilities and the entirety of the City is considered vulnerable to extreme weather hazards.

Extreme heat does not physically damage buildings, but it can impact City operations resulting in human health concerns such as heat stroke. The day-to-day operations of residents and businesses may be also hindered due to extreme heat if no air conditioning is present. In some cases, cooling centers may be used to temporarily address the health effects of extreme heat. Extreme heat events can also increase the burden on power suppliers due to increased electricity consumption leading to power outages.

Santa Ana Wind events could cause damage to buildings or infrastructure, although events are generally not significant enough to damage critical facilities or substantially impact operations.

Significant Santa Ana Wind events are known to cause communication issues, which can disrupt technology infrastructure or result in response challenges. PSPS events are also activated to prevent wildfires that are fanned by Santa Ana winds. Heavy rains can result in physical access challenges to critical facilities if roads are flooded or otherwise unsafe for access.

Since the 2019 LHMP, development and land use has not substantially changed in the planning area. In the five years since the approval of the previous LHMP, only one significant housing development was identified in the City’s most recent 2021-2029 Housing Element: the construction of approximately thirty single family homes on a former Department of Water and Power (DWP) site at the intersection of Marina Drive and 1st Avenue. Other land use changes since the 2019 LHMP were limited in scope, such as the addition of ADUs, and/or lot line adjustments.

As these changes were minor in size and scale, vulnerability is not considered to have significantly changed in the past five years.

As development and land use in the planning area has not substantially changed since the 2019 LHMP, population trends have also remained relatively the same. United States Census Data reports a 2020 population of 25,232 and a 2023 population of 24,868, representing a 1.44 percent population decline. Generally, observed population decline in the planning area is associated with an overall aging population.

Looking forward, the City anticipates the majority of population growth would align with the 2021-2029 Housing Element, which proposes to accommodate the City’s Regional Housing Needs City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE

6.6.2 CHANGES IN VULNERABILITY FROM PREVIOUS FIVE YEARS

6.6.3 CHANGES IN VULNERABILITY FOR FUTURE FIVE YEARS
Section 6. Extreme Weather Hazard Assessment September 2025 Allocation of 1,243 units largely at commercial sites which are proposed to be rezoned for mixed use. These areas may be impacted by extreme weather especially areas along the coastline areas with additional flooding caused by coastal storms. Areas with insufficient drainage may also be greatly impacted by extreme weather such as heavy rains. Based on anticipated growth and development, it is reasonable to assume that vulnerability to extreme weather will increase over the 5-year planning period of this LHMP.

Section 3.7 includes a detailed determination of Socially Vulnerable Populations (SVPs) within the planning area and characteristics that make those populations more vulnerable to hazards. The SVPs include census tracts 995.09, 995.10, 995.02 and the Seal Beach Shores Mobile Home Park.

The impacts of extreme weather would apply to the entirety of the planning area, including SVPs within census tracts 995.09, 995.10, 995.02 and the Seal Beach Shores Mobile Home Park.

Specific SVPs and high-risk individuals that may be present throughout the planning area include unemployed individuals, elderly populations age 65 and older, young populations under age 17, persons with disabilities, persons with high pollution burden, and tourists, seasonal visitors, and homeless populations. The primary concern for SVPs and other high-risk individuals in the City would be evacuation efforts, access to emergency services and supplies, and recovery.

Unemployed individuals may be more vulnerable to extreme weather hazards as they may be limited in financial resources to prepare for disasters, such as purchasing emergency supplies, securing adequate housing, or evacuating to safer areas with sufficient transportation.

Additionally, unemployed individuals may have substandard housing that may not have air conditioning during extreme heat events or sufficient protection against heavy rains and Santa Ana winds and tornadoes. These populations may not have resources to seek medical care following an extreme weather hazard event. These social and economic disparities can further hinder their ability to recover, as unemployed individuals face a greater risk of long-term displacement and financial hardship following an extreme weather hazard event.

Young populations under age 17 may be more vulnerable to the impacts of extreme weather hazards due to being more susceptible to injuries and illnesses as their bodies are still developing.

Younger children may also have limited mobility and awareness to evacuate in a timely manner during a disaster and may have a hard time withstanding the force of floodwater from heavy rains or the high temperatures of extreme heat. Younger populations rely heavily on adults for protection, care, and decision-making; thus, if parents/guardians/caregivers are affected by a disaster, the child’s safety and well-being may be compromised. Additionally, flooding from heavy rains can lead to school closures and displacement, which may disrupt children’s education and social development.

Elderly populations age 65 and older are more vulnerable to extreme weather hazards. Persons aged 65 or older often face several challenges when responding to an emergency, such as mobility challenges, health concerns, social isolation, barriers to transportation, and limited access to information or technology. In addition, there is often overlap between persons aged 65 or older and persons with a disability, as older adults experience increased prevalence of disabilities. This could include cognitive impairment, difficulties with independent living or hearing and vision DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

6.7 SOCIALLY VULNERABLE POPULATIONS ASSESSMENT
September 2025 Section 6. Extreme Weather Hazard Assessment problems. Lastly, this population may rely on caregivers for their well-being; thus, evacuation may be more difficult if this service is disrupted.

Similarly, persons with disabilities are highly vulnerable to extreme weather hazards due to mobility challenges, having difficulty transporting to cooling centers or evacuating quickly, and navigating through heavy rains. This population may have more underlying health conditions that can be exacerbated by extreme heat, heavy rains, and Santa Ana winds. In the event of a PSPS, there may be communication barriers to this population as emergency alerts and information may only be accessible in limited communication mediums. Extreme weather events may not allow technology to function properly, especially during a PSPS event. Lastly, persons with disabilities may rely on caregiving services, which may be disrupted during extreme weather events and make evacuation difficult.

Persons exposed to areas with a high pollution burden are more vulnerable to extreme weather events for a variety of reasons. Extreme weather hazards can further exacerbate populations with high pollution burdens who are already exposed to high pollution levels and may have weakened respiratory and cardiovascular systems. Additionally, extreme heat can exacerbate underlying illnesses from pollution exposure. Communities with high pollution often face economic challenges, making it harder to prepare and recover from extreme weather events. Lastly, persons dwelling in areas with a high pollution burden may have older, less resilient infrastructure, increasing their vulnerability during an extreme weather event and ultimately leading to prolonged exposure to hazardous conditions.

Lastly, tourists, seasonal visitors, and homeless populations are particularly vulnerable during extreme weather events due to their lack of familiarity with the area and lack of established support systems. They may not be aware of evacuation routes or local emergency procedures, making it difficult for them to respond quickly. Additionally, they might not have access to timely information about the extreme weather event or the resources needed to cope with the aftermath.

The City hosts multiple community events throughout the year and nearby Huntington Beach and Long Beach are expected to host sizeable events for the upcoming 2028 Olympic Games, indicating increased present and future vulnerability. These factors make SVPs throughout Seal Beach especially vulnerable to the impacts of extreme weather.

Considerations for SVPs throughout the planning area were incorporated into the mitigation strategy in Section 11.0, Mitigation Strategy. Specifically, the LHMP Planning Team tailored Mitigation Actions P.1, P.8, 1.8, 5.4, and 5.9 to mitigate hazard impacts to SVPs including issues related to preparedness, evacuation, and access to emergency services.

City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 6. Extreme Weather Hazard Assessment September 2025

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Landslide and Slope Failure
Landslide is a generalized term for a falling mass of soil or rocks. When a hillside or slope becomes unstable, downslope movement of rock and soil occurs under the direct influence of gravity. Landslides are often sudden, although some occur very slowly over a long period of time.

Loose and fractured materials are more likely to slide than compact materials or solid rock, and steep slopes are at greater risk than gentle rises.

Landslides are usually induced by either earthquakes or saturated slopes. The shaking of an earthquake can decrease slope stability, or in a more severe instance, fracture the earth material enough that the material slides. Moisture-induced landslides can occur when the ground soaks up enough water that the soil becomes loose and unstable. This is often the result of intense or long-lasting rainfall but can also result from a pipeline burst or overwatering landscapes. Loss of vegetation to fire or drought may cause an area to be more vulnerable to landslides. Vegetation holds soil in place and without the root system of trees, bushes, and other plants, the land is more likely to slide away.

One type of landslide that is different from debris flows or rock flows are deep-seated landslides. Deep-seated landslides are not necessarily triggered by any single storm or earthquake. Rather, these types of landslides occur weeks to months after heavy rainfall ends, when water has had time to percolate deeper under the surface to saturate weak zones of rock. This creates a “landslide plane” under the saturated weight of the overlying rock and soil. The landslide plane may often be associated with earlier slides and can occur regardless of whether rain is occurring or not. As these landslides begin so deeply, they tend to carry more material and cover more territory than other types of slides.

Deep-seated landslides generally occur on moderately steep slopes, travel much slower than mudflows or debris flows, and can continue for several days.

SECTION 7: LANDSLIDE HAZARD

ASSESSMENT

7.1 LANDSLIDE

7.1.1 DESCRIPTION
Regardless of the cause or specific form, a landslide can damage or destroy structures or roadways in its path. Underground infrastructure, such as pipelines or telecommunication lines, may be severed during a landslide. This could lead to infrastructure induced flooding if water pipes, or sewage lines burst. In addition to property damage, landslides can crush or bury people, creating a risk of serious injury or death.

In addition, sinkholes are a related geologic hazard that regularly affect the planning area.

Sinkholes are depressions in the ground that form when the underlying rock and soil has been dissolved, eroded, or saturated by water and collapses. A sinkhole has no natural external surface drainage; thus all water remains in the sinkhole and typically drains into the subsurface.1 2 While sinkholes can naturally occur due to weathering and erosion of surface rock (especially limestone), sinkholes are most often triggered in the planning area by heavy rains or flooding.

The City of Seal Beach is a relatively flat city with some elevation shifts, however there are few deep-seated landslide potential zones mapped throughout the City of Seal Beach; refer to Figure 7-1, Deep-Seated Landslide Hazard Zones. Although limited areas of the City face risk to landslide, mapped landslide risk areas primarily include portions of the Pacific Coast Highway, the Interstate 405, Bolsa Chica Rd, Golden Rain Rd, the Naval Weapons Station, and Gum Grove Park.

The extent of a landslide event is largely dependent on the quantity of slope failure, measured in cubic meters or yards. Landslide events of greater magnitude will be associated with larger quantities of slope failure. It is noted that areas of the landslide hazard zone in and around Gum Grove Park intersect with the Alquist-Priolo Earthquake Fault Zones, as discussed in Section 8.0.

This area could see a more significant extent of landslide hazards if there is strong seismic ground shaking or fault rupture along the Newport Inglewood Fault within the planning area.

The City of Seal Beach has experienced few landslides and sinkholes during the past five years.

One sinkhole formed from December 2023 to January 2024 in a flooded parking lot after high surf storms caused flooding in the area.3 No notable or significant landslide events have impacted the City within the last five years. No federally or state declared disasters related to landslide events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.
1 USGS, What is a sinkhole? https://www.usgs.gov/faqs/what-a-sinkhole, updated March 7, 2024, accessed December 30, 2024.
2 California Department of Conservation, 2023 California Landslide Response, https://www.conservation.ca.gov/cgs/landslides/2023, accessed December 30, 2024. 3 ABC7, Sinkhole forms in parking lot of Seal Beach restaurant after high surf causes flooding, https://abc7.com/seal-beach-restaurant-sinkhole-orange-county-high-surf/14260406/, published January 3, 2024, accessed December 3, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

7.1.2 LOCATION/EXTENT

7.1.3 PREVIOUS OCCURRENCES
Section 7. Landslide Hazard Assessment September 2025
Figure 7-1
Deep-Seated Landslide Hazard Zones
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Dofo Sourced: 2010
September 2025 Section 7. Landslide Hazard Assessment
Given the location of the City and previous occurrences, the probability of landslides and slope failure continuing to occur within the City of Seal Beach is considered occasional. An occasional probability means there is a 1 to 10 percent probability of occurrence in the next year or a recurrence interval of 11 to 100 years. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt that landslide will likely affect the planning area in the future and therefore felt “occasional” best defined probability for this specific hazard. The LHMP planning team assigned a medium hazard planning consideration to the hazards and impacts associated with landslide and slope failure based upon an occasional probability and widespread expected impacts of future events.

No federally declared disasters related to landslide and slope failure events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Landslides are generally caused by one of two factors: seismic activity or soil saturation.

Earthquakes and ground shaking are not linked to climate change; however, heavy rains are affected by climate change and understood to contribute to saturated soils and landslides. Climate change is linked to increased precipitation and more frequent and/or severe storms. California is already experiencing climate change impacts with increasingly variable precipitation and becoming the highest variability of year-to-year precipitation in the contiguous United States.4 Increased rainfall due to climate change will lead to saturated slopes, erosion, and likely will exacerbate the effects of landslide within the planning area.

Critical facilities located within the landslide hazard zone include those that serve as transportation, water systems, safety and security, communications, and hazardous materials lifelines. In total, there are 26 vulnerable critical facilities located within the City’s landslide hazard zone. Government service and parks and recreation are the primary asset types within the landslide hazard zone, however other types of critical facilities have also been identified as vulnerable. Critical facilities located within the City’s identified landslide hazard zone have been listed in Table 7-1, Critical Facilities in Landslide Hazard Zone.

To identify populations at risk for landslide hazards, hazard data layers were overlaid and compared with City parcel data in Geographic Information Systems, ArcGIS. If a hazard layer either completely or partially overlapped with a parcel in the data layer, then the entire parcel is conservatively considered vulnerable in this analysis. In many instances, the landslide hazard zone intersected with only small portions of individual properties. However, to provide a detailed understanding of risk and vulnerability as part of this hazard mitigation plan, these parcels 4 California Climate Adaptation Strategy, Summary of Projected Climate Change Impacts on California, https://climateresilience.ca.gov/overview/impacts.html#:~:text=California%20is%20already%20experie ncing%20the,have%20increased%20as%20temperatures%20warm, accessed December 30, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

7.1.4 PROBABILITY OF FUTURE OCCURRENCES

7.1.5 CLIMATE CHANGE

7.2 VULNERABILITY ASSESSMENT

7.2.1 HAZARD VULNERABILITY ASSESSMENT
Section 7. Landslide Hazard Assessment September 2025
(including all residential and non-residential development on the parcel, regardless of location) are considered vulnerable.

Approximately 1,118 residential units are located within the landslide hazard zone. The vulnerability assessment cross-referenced hazard layers with parcel data layers in GIS. The number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that approximately 2,125 people reside in the landslide hazard zone.

Additionally, approximately 1,539,355.2 square feet of non-residential structures are located within the landslide hazard area. Refer to Table 7-2, Populations at Risk for Landslide for a summary of vulnerable residents, residential units, and non-residential buildings.

Table 7-1
Critical Facilities in Landslide Hazard Zone
Map ID Name Asset Type Community Lifeline Replacement
Value
9 Sewer lift pump
station - 1776 ½
Adolfo Lopez Dr
Water Systems Water Systems $1,050,000
15 Seal Beach Marine
Safety
Headquarters
Government
Services
Safety and Security,
Communications
$3,129,060
23 San Gabriel River
Bike Trail Entry
Point
Transportation Transportation Not Available
26 Stormwater
Pump Station
(County owned)
Water Systems Water Systems Not Available
28 Bridge 55C0041L
- Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
29 Bridge 55C0041R
- Los Alamitos
Channel (Local)
Transportation Transportation $1,574,100
30 Bridge 55C0042L
- Federal Storm
Channel
(Local)
Transportation Transportation $1,690,700
31 Bridge 55C0042R
- Federal Storm
Channel
(Local)
Transportation Transportation $1,906,410
32 Bridge 55C0075 -
Westminster
Channel
(Local)
Transportation Transportation $5,281,980
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 7. Landslide Hazard Assessment
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Value
35 Bridge 55C0108 -
Bolsa Chica
Channel (Local)
Transportation Transportation $5,888,300
37 Bridge 53 0060 -
San Gabriel River
(State)
Transportation Transportation $18,073,000
38 Bridge 53 0302L -
San Gabriel River
(State)
Transportation Transportation $9,969,300
39 Bridge 53 0302R -
San Gabriel River
(State)
Transportation Transportation $9,969,300
40 Bridge 53 1185 -
San Gabriel River
(State)
Transportation Transportation $35,563,000
41 Bridge 53 1737H
- San Gabriel
River (State)
Transportation Transportation $7,287,500
42 Bridge 55 0010 –
Anaheim Bay
(State)
Transportation Transportation $16,673,800
43 Bridge 55 0065 -
Kitt Highway, US
Navy RR (State)
Transportation Transportation $6,879,400
44 Bridge 55 0310 –
Los Alamitos
Channel (State)
Transportation Transportation $9,328,000
45 Bridge 55 0334 -
Bolsa Chica Ditch
(State)
Transportation Transportation $67,045,000
51 Bridge 55 0426G
–
S605 - S405
Connector (State)
Transportation Transportation $12,458,710
53 Bridge 55 0441 -
Los Alamitos
Channel (State)
Transportation Transportation $15,158,000
55 Bridge 55 1100G -
Interstate 405
(State)
Transportation Transportation $44,308,000
70 Police Substation Municipal
Services
Safety and Security;
Communications
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79 Eisenhower Park Public Park Safety and Security $700,000 D
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City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 7. Landslide Hazard Assessment September 2025
Map ID Name Asset Type Community Lifeline Replacement
Value
86 City Maintenance
Yard
Maintenance Yard Hazardous Materials $4,064,100
88 College Park
Drive Bridge over
San Gabriel River
Bridge Transportation Not Available
Table 7-2
Populations at Risk for Landslide
Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
2,125 1,118 1,539,355.2
Since the 2019 LHMP, development and land use has not substantially changed in the planning area. In the five years since the approval of the previous LHMP, only one significant housing development was identified in the City’s most recent 2021-2029 Housing Element: the construction of approximately thirty single family homes on a former Department of Water and Power (DWP) site at the intersection of Marina Drive and 1st Avenue. Other land use changes since the 2019 LHMP have been limited in nature, such as the addition of ADUs, and/or lot line adjustments. As these changes were minor in size and scale, vulnerability is not considered to have significantly changed in the past five years.

As development and land use in the planning area has not substantially changed since the 2019 LHMP, population trends have also remained relatively the same. United States Census Data reports a 2020 population of 25,232 and a 2023 population of 24,868, representing a 1.44 percent population decline. Generally, observed population decline in the planning area is associated with an overall aging population.

Looking forward, the City anticipates the majority of population growth would align with the 2021-2029 Housing Element, which proposes to accommodate the City’s Regional Housing Needs Allocation of 1,243 units largely at commercial sites which are proposed to be rezoned for mixed use. These areas may be impacted by a landslide, especially areas along the coastline areas, along with western and northern portions of the City. Based on anticipated growth and development, it is reasonable to assume that vulnerability to landslide hazards will increase over the 5-year planning period of this LHMP.

Section 3-7 includes a detailed determination of Socially Vulnerable Populations (SVPs) within the planning area and characteristics that make those populations more vulnerable to hazards. The SVPs include census tracts 995.09, 995.10, 995.02 and the Seal Beach Shores Mobile Home Parks.

Census tracts 995.09, 995.10, 995.02 have areas of vulnerability in the event of a landslide event.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

7.2.2 CHANGES IN VULNERABILITY FROM PREVIOUS FIVE YEARS

7.2.3 CHANGES IN VULNERABILITY FOR FUTURE FIVE YEARS

7.3 SOCIALLY VULNERABLE POPULATIONS ASSESSMENT
September 2025 Section 7. Landslide Hazard Assessment
SVPs and other high-risk individuals exist throughout the planning area and may be present within landslide hazard zones despite a census tract’s social vulnerability classification. Specific SVPs and high-risk individuals that may be present throughout the planning area and landslide hazard zones include unemployed individuals, elderly populations age 65 and older, young populations under age 17, persons with disabilities, persons with high pollution burden, and tourists, seasonal visitors, and homeless populations. The primary concern for SVPs and other high-risk individuals in the City would be evacuation efforts, access to emergency services and supplies, and recovery.

Unemployed individuals may be more vulnerable to the landslide hazard as they may be limited in financial resources to prepare for disasters, such as purchasing emergency supplies, securing adequate housing, or evacuating to safer areas with transportation. Additionally, unemployed individuals may have substandard housing which may be more susceptible to damage during a landslide event. These populations may not have resources to seek medical care following a landslide hazard event. These social and economic disparities can further hinder their ability to recover, leaving them at greater risk of long-term displacement and financial hardship following a landslide.

Young populations under age 17 may be more vulnerable to the impacts of landslide hazards due to facing higher susceptibility to injuries and illnesses as their bodies are still developing. Younger children may also have limited mobility and awareness to evacuate in a timely manner during a disaster, as they rely heavily on adults for protection, care, and decision-making. Additionally, a landslide event can cause school closures and displacement, which may disrupt children’s education and social development.

Elderly populations aged 65 and older are more vulnerable to landslide events. Persons aged 65 or older often face several challenges when responding to an emergency, such as mobility challenges, health concerns, social isolation, barriers to transportation, and limited access to information or technology. In addition, there is often overlap between persons aged 65 or older and persons with a disability, as older adults experience increased prevalence of disabilities. This could include cognitive impairment, difficulties with independent living, or hearing and vision problems. Lastly, this population may rely on caregivers for their well-being; thus, evacuation may be more difficult if this service is disrupted.

Similarly, persons with disabilities are highly vulnerable to landslides due to mobility challenges that make it difficult to navigate and evacuate during a disaster. This population may have more underlying health conditions that can be exacerbated by the stress and demands of a landslide event. There may be communication barriers to this population as emergency alerts and information may only be accessible in limited communication mediums. Landslide hazards can damage or destroy essential assistive devices such as wheelchairs, hearing aids, communication devices, and other medical technology SVPs may rely on. Additionally, persons with disabilities might rely on caregiving services, which may be disrupted during a landslide disaster and make it difficult to evacuate.

Considerations for SVPs throughout the planning area were incorporated into the mitigation strategy in Section 11.0, Mitigation Strategy. Specifically, the LHMP Planning Team tailored City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 7. Landslide Hazard Assessment September 2025
Mitigation Actions P.1, P.8, 1.8, 5.4, and 5.9 to mitigate hazard impacts to SVPs including issues related to preparedness, evacuation, and access to emergency services.

DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 7. Landslide Hazard Assessment
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Fault Rupture
The US Geological Survey (USGS) defines an earthquake as a sudden slip on a fault and the resulting ground shaking and radiated seismic energy caused by the slip (or any other sudden stress changes in the earth).

Faults are fractures along the earth’s crust between two blocks of earth and can be defined as a strike slip, normal, or thrust faults. Earthquakes occur without warning, and result in effects such as fault rupture, ground motion, liquefaction, and landslides described below.

Fault rupture or surface faulting is the differential movement of two sides of a fracture, where the ground breaks apart. The length, width, and displacement of the ground characterize surface faults, which occur based on the type of underlying fault. Faults occur at boundaries between large sections of the earth’s surface, called tectonic plates.

Most of California underlies the North American plate, but coastal areas (including the City of Seal Beach) are on the Pacific plate. The San Andreas Fault is the main boundary between North American and Pacific plates, but other fault lines can be found up to 200 miles away.

The presence of the San Andreas Fault and other regional faults is the reason for frequent seismic activity in California.

SECTION 8: SEISMIC HAZARD

ASSESSMENT

8.1 FAULT RUPTURE/GROUND MOTION

8.1.1 DESCRIPTION
Where surface traces of active faults are found in California, an Alquist-Priolo fault zone is mapped.

A regulatory zone, which is a 500-foot buffer, is then created around the mapped Alquist-Priolo fault zone.1 If an active fault has a potential for surface rupture, a structure for human occupancy cannot be placed over the fault and must be a minimum distance from the fault (generally fifty feet). The intent of the Alquist-Priolo Act is to reduce losses from surface fault rupture, and to prevent the construction of buildings used for human occupancy on the surface trace of active faults. Before a new development is permitted, cities and counties require a geological investigation to demonstrate that proposed buildings will not be constructed on active faults. 234 Ground Motion
Ground motion is the movement of the earth's surface from earthquakes. Ground motion is produced by seismic waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the earth and along its surface.5 Seismic waves produce ground vibrations above the surface. The severity of the vibration increases with the amount of energy released and decreases with distance from the causative fault or epicenter. Soft soils can further amplify ground motion.6
Seismic shaking can be strong enough to result in widespread devastation or be virtually undetectable by the average person. The intensity of seismic shaking is a result of the release by the fault rupture (how much of the accumulated stress was released), the length of the rupture (the longer the slip along the fault line, the greater the shaking), and the depth at which the rupture occurs (ruptures that occur closer to the surface often cause stronger shaking). Usually, areas closest to the site of the rupture experience the greatest shaking, although differences in geology and soil can also have an impact. Seismic shaking can damage or destroy buildings and structures and may cause partial or total collapse. Ground movement can damage or destroy infrastructure on or beneath the surface, such as roads, rail lines, and utility lines and pipes. This in turn, can cause hazardous materials releases, water main breaks, and other dangerous situations resulting from infrastructure failure. Falling debris and structures also create a risk of injury or death.

Ground motion affecting the City of Seal Beach would be particularly damaging to residential buildings constructed of wood or reinforced masonry construction, and to mobile homes. Other buildings that do not typically perform well in earthquakes are soft-story buildings. These types of buildings have a story (typically the first floor) that lacks adequate strength or toughness due to too few shear walls. The percentage of ground motion shake potential is shown in Figure 8-1, Shake Potential.
1 California Department of Conservation, Alquist-Priolo Earthquake Fault Zones, https://www.conservation.ca.gov/cgs/alquist-priolo, accessed December 26, 2024. 2 USGS, Alquist-Priolo Faults, https://earthquake.usgs.gov/education/geologicmaps/apfaults.php, accessed December 26, 2024.
3 USGS, Earthquake Glossary – Earthquake, https://earthquake.usgs.gov/learn/glossary/?term=earthquake, accessed December 26, 2024.
4Geology.com, The San Andreas Fault, https://geology.com/articles/san-andreas-fault.shtml, accessed December 26, 2024.
5 USGS, Earthquake Glossary – Ground Motion, https://www.usgs.gov/glossary/earthquake-hazardsprogram, accessed December 26, 2024. 6 FEMA, Multi-Hazard Identification and Risk Assessment - Subpart D: Seismic Hazards, January 1, 1997.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

8.1.2 LOCATION/EXTENT
Section 8. Seismic Hazard Assessment September 2025
Figure 8-1
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Projection: California State Plane Coordinate System Zone 6, NAD 83
Doto Sourced: 2016
September 2025 Section 8. Seismic Hazard Assessment
The most common measures of ground shaking during an earthquake event, the Moment Magnitude and Modified Mercalli Intensity scales, are described below.

There are two scales commonly used by scientists to measure earthquakes: the Moment Magnitude Scale and the Modified Mercalli Intensity Scale. The moment magnitude scale is based on the now largely unused Richter scale and measures the amount of energy released by the earthquake. The Modified Mercalli Intensity Scale (MMI Scale) measures the effects of the earthquake and is based on qualitative observations rather than a mathematical basis. The intensity scale consists of a series of certain key responses such as people awakening from sleep, movement of furniture, damage to chimneys, and destruction. Although numerous scales have been developed to evaluate earthquake effects, the scale currently used in the United States is the Modified Mercalli Intensity Scale. This scale, composed of twelve increasing levels of intensity ranging from imperceptible shaking to catastrophic destruction, is designated by Roman numerals I through XII. Table 8-1, Modified Mercalli Intensity Scale, shows the different categories of the Mercalli intensity scale.

Magnitude and intensity measure different characteristics of earthquakes but often correlate.

Magnitude measures the energy released at the source of the earthquake, determined by measurements on seismographs. Intensity measures the strength of shaking produced by an earthquake at a certain location, and is determined by effects on people, structures, and the natural environment. Refer to Table 8-2, Approximate Comparison of Moment Magnitude and Mercalli Intensity Scales, which lists the intensities that are typically observed at locations near the epicenter of earthquakes of different magnitudes.

Table 8-1
Modified Mercalli Intensity Scale
Category Description Possible Impacts
I Non felt Not felt except by a very few under especially favorable conditions.

II Weak Felt only by few persons at rest, especially on upper floors of buildings.

III Weak Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated.

IV Light Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building.

Standing motor cars rocked noticeably.

V Moderate Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum
clocks may stop.

VI Strong Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.

VII Very Strong Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures;
City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 8. Seismic Hazard Assessment September 2025
Category Description Possible Impacts
considerable damage in poorly built or badly designed
structures; some chimneys broken.

VIII Severe Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse.

Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.

IX Violent Damage considerable in specifically designed structures; welldesigned frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.

X Extreme Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent.

Source: USGS, The Modified Mercalli Intensity Scale, https://www.usgs.gov/natural-hazards/earthquakehazards/science/modified-mercalli-intensity-scale?qt-science_center_objects=0#qt-science_center_objects, accessed December 26, 2024.

Table 8-2
Approximate Comparison of Moment Magnitude and Mercalli Intensity Scales Moment Magnitude Mercalli Intensity

1.0 to 3.0 I

3.0 to 3.9 II to III

4.0 to 4.9 IV to V

5.0 to 5.9 VI to VII

6.0 to 6.9 VII to IX

7.0 and greater VIII and greater
Source: USGS, Magnitude/Intensity Comparison, http://earthquake.usgs.gov/learn/ topics/mag_vs_int.php, accessed August 11, 2015.

The City of Seal Beach is located within the Southern California region, known to be seismically active. The faults located within the boundaries of the City include Newport-Inglewood, Rose Canyon Fault, and the Los Alamitos fault. Other active faults that are close to the City within five miles include the Compton thrust fault and THUMS Huntington Beach fault. Figure 8-2, Seismic Hazards, shows fault zones near the City of Seal Beach as well as earthquake epicenters.7 Table 8- 3, Local Known Earthquake Faults Within 10 Miles of Seal Beach, lists each active and potentially active fault near the City, distance to the City, estimated magnitude, and class type. All faults listed below are active or potentially active and are categorized as class type A, where there is geological evidence demonstrating the existence of Quaternary fault of tectonic origin, whether the fault is exposed for mapping or inferred from liquefaction or other deformational features.8 7 Source: California Department of Conservation, California’s Big Earthquakes, https://www.conservation.ca.gov/cgs/earthquakes/big, revised July 11, 2024, accessed April 24, 2025. 8 USGS, Faults, https://www.usgs.gov/programs/earthquake-hazards/faults, accessed December 26, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 8. Seismic Hazard Assessment
Figure 8-2
Seismic Hazards
City of Seal Beach Local Hazard Mitigation Plan
an F.ernand
Feb. 9 1971

6.6Mw
Legend
D
•
0 Seal Beach
Boundary
Earthquake Epicenter
Historic Faults
Late Quarternary Faults
Latest Quarternary Faults
Undifferentiated Quarternary
Faults
8 16 miles
Section 8. Seismic Hazard Assessment

DRA DE,IBERA IVE
Wrightwood
Dec. 8 1812
Source: CA Dept. of Conservation, USGS, Southern Coli
Earthquake Doto Center, Ciry of Seal Beach, fari
Projection: California State Plane Coordinate System Zone 6, NA 3 Doto Updated: December 18, 2019
September 2025
Table 8-3
Local Known Earthquake Faults Within 10 Miles of Seal Beach Fault Name
Distance1
(miles)
Type of
Faulting
Last Major
Rupture
Slip
Rate
(mm/yr)
Estimated
Magnitude2
(mW)
NewportInglewood
Fault Zone
Within City
Boundaries
Right-lateral;
local reverse
slip
associated
with fault
steps
March 10, 1933,
MW 6.4 (but no
surface rupture)

0.6 6.0-7.4
Los
Alamitos
Fault
Within City
Boundaries
Uncertain Uncertain Uncertain Uncertain
Garden
Grove Fault
Within City
Boundaries
Uncertain Uncertain Uncertain Uncertain
Compton
Thrust
Fault9
1 Blind thrust
fault
Uncertain but
suggested
Holocene

0.2 – 1.0 7.0 – 7.4
THUMS
Huntington
Beach10

2.6 Blind thrust
fault
Late Quaternary Uncertain 6.7 – 6.8*
Wilmington
blindthrust11

2.8 Blind thrust
fault
Uncertain 0.23 -

0.59 6.2 – 6.3
San Joaquin
Hills
thrust12,
13 6.6 Blind thrust
fault
Uncertain 0.2 – 1.0 >7.0
Palos
Verdes fault

6.9 Right-reverse Holocene,
offshore; Late

0.1 – 3.0 6.0 - 7.0
9 Statewide California Earthquake Center, Evidence for Large Holocene Earthquakes on the Compton Thrust Fault, Los Angeles, California, https://central.scec.org/publication/1294, accessed December 26, 2024. 10 Harvard University and University of Southern California, U.S. Geological Survey, Final Technical Report:

Activity and earthquake potential of Wilmington blind thrust, Los Angeles, CA: The largest earthquake source not on current southern California hazard maps? Collaborative Research with Harvard University and University of Southern California,
https://earthquake.usgs.gov/cfusion/external_grants/reports/G17AP00008.pdf, published 2017, accessed December 27, 2024.
11 Bulletin of the Seismological Society of America, The Wilmington Blind-Thrust Fault: An Active Concealed Earthquake Source beneath Los Angeles, California, https://hcbf.org/wp-content/uploads/2019/09/TheWilmington-Blind-Thrust-Fault-cmplt-Franklin-D.-Wolfe-17-pgs..pdf, published 2019, accessed December 27, 2024.
12 USGS Quaternary Fault and Fold Database of the United States, https://earthquake.usgs.gov/static/lfs/nshm/qfaults/Reports/186.pdf, last reviewed February 18, 2017, accessed December 30, 2024.
13 Energy Blog, San Joaquin Hills Blind Thrust Fault Scenario, https://sites.uci.edu/energyobserver/2012/04/25/san-joaquin-hills-blind-thrust-fault-scenario/, posted April 25, 2012, accessed December 30, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 8. Seismic Hazard Assessment
Fault Name Distance1
(miles)
Type of
Faulting
Last Major
Rupture
Slip
Rate
(mm/yr)
Estimated
Magnitude2
(mW)
Quaternary,
onshore
Lower
Elysian Park
thrust14

7.25 Blind thrust
fault
Undifferentiated
Quaternary

2.5 - 5.2 6.2 – 6.7
Puente Hills
blind thrust
system15

8.5 Blind thrust
fault
1987 Whittier
Narrows
Earthquake

0.44 – 1.7 7.5
Cabrillo
fault

9.8 Right-normal Holocene,
offshore; Late
Quaternary,
onshore
Unknown 6.0 - 6.8
Newport-Inglewood Fault Zone
Of the three faults that traverse the City of Seal Beach, the Newport-Inglewood Fault Zone fault is the most notable, traversing the City from northwest to the southern portion of the City. The system is capable of producing a 6.9 magnitude earthquake and has a slip rate of 1mm/yr. Because of its proximity to the City, it is thought to present a greater danger to the City in terms of death and destruction than the San Andreas fault. The Newport-Inglewood Fault Zone includes fault segments Charnock Fault, Overland Avenue Fault, Inglewood Fault, Portero Fault, AvalonCompton Fault, Cherry Hill Fault, and Seal Beach Fault. The movement on this fault zone caused the 1933 Long Beach magnitude 6.3 earthquake and the 1920 Inglewood earthquake, with an estimated magnitude 4.9. The 1933 Long Beach earthquake resulted in 120 deaths and over $50 million in property damage. Most of the damaged buildings were of unreinforced masonry. Many school buildings were destroyed. In addition to the Newport-Inglewood Fault Zone, seismic data shows there are additional near-surface faults, some of which are currently active.16 This NewportInglewood Fault Zone has the potential to sink the Seal Beal Wildlife Refuge up to 3 ft should a 7.5 mW occur.17
The Los Alamitos Fault
The Los Alamitos fault traverses a small portion of the City northeastern portion of the City. Much is unknown about the fault including its age, and magnitude. However, the fault system is known 14 USGS Quaternary Fault and Fold Database of the United States, Lower Elysian Park thrust (Class A) No. 134, https://earthquake.usgs.gov/static/lfs/nshm/qfaults/Reports/134.pdf, last review date June 14, 2017, accessed December 30, 2024.
15 Bulletin of the Seismological Society of America, Puente Hills Blind-Thrust System, Los Angeles California, http://activetectonics.asu.edu/bidart/bibliography/bssa/bssa_92_8/shaw_plesch_dolan_pratt_fiore_2002.p df, published December 2002, accessed December 30, 2024. 16 Temblor, Newly identified fault in Seal Beach, CA quietly rattles beneath the city, https://temblor.net/earthquake-insights/newly-identified-fault-in-seal-beach-ca-quietly-rattles-beneaththe-city-13477/, published November 8, 2021, accessed December 26, 2024. 17 USGS, History of Abrupt Sinking of the Seal Beach Wetlands: New Study Reveals Past Quakes along Fault and Offers Glimpse into the Future, https://www.usgs.gov/news/state-news-release/history-abrupt-sinkingseal-beach-wetlands-new-study-reveals-past-quakes, published March 20, 2017, accessed December 31, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 8. Seismic Hazard Assessment September 2025
to be a part of a larger system called the Compton-Los Alamitos Fault. The type of fault is approximately 11 km. 18 The most recent surface rupture of this fault occurred in the Late Quaternary period.

Garden Grove Fault
Recently, USGS conducted a high-density seismic survey of the subsurface and identified new subsurface faults between the Los Alamitos fault and the Newport Inglewood Fault. The Garden Grove Fault is located approximately 1.5 miles northeast of the Newport-Inglewood Fault Zone and appears to be active and primarily responsible for the formation of the Seal Beach Anticline (SBA). 19 The location of the Garden Grove Fault is not mapped in Figure 8-2, Seismic Hazards due to its more recent discovery in 2021; however, the approximate location is shown in Figure 8-3, Location of Garden Grove Fault
Figure 8-3
Location of Garden Grove Fault
Temblor, Newly identified fault in Seal Beach, CA, quietly rattles beneath the city, https://temblor.net/earthquake-insights/newly-identified-fault-in-seal-beach-ca-quietly-rattles-beneaththe-city-13477/, published November 8, 2021, accessed December 27, 2024. 18 Southern California Earthquake Data Center, Los Alamitos Fault, https://scedc.caltech.edu/earthquake/losalamitos.html, published 2024, accessed December 26, 2024. 19 Los Angeles Basin Geological Society, February 2023 Newsletter: Tectonic Evaluation of Seal Beach Anticline Using Modern 3D Seismic, https://www.labgs.org/newsletters/labgs_2023-02.pdf, published February 2023, accessed December 27, 2024.

DW DI !ERA VE
B
...
.....,...........,.,_ 0
City of Seal Beach Local Hazard Mitigation Plan
3D Seismic Solutions: Active Surface Faults
-----:---l In Long Beach & Seal Beach Area (SBNWS)
3D SE SM SOLUT ONS
Location of the newly identified shallow faults (purple), areas of recent deformation (red) and the current surface trace of the NIFZ (yellow).

September 2025 Section 8. Seismic Hazard Assessment
Alquist-Priolo Earthquake Fault Zones
Alquist-Priolo earthquake fault zones are regulatory zones surrounding the surface traces of active faults in California as mapped and defined by the California Department of Conservation. The Alquist-Priolo Earthquake Fault Zoning Act is a California law enacted in 1972 to reduce the risk of damage from surface rupture during earthquakes. Areas within the eastern portion of the City of Seal Beach are located within an Alquist-Priolo Earthquake Fault Zone due to the presence of the Newport-Inglewood Rose Canyon fault zone; refer to Figure 8-4, Alquist-Priolo Earthquake Fault Zone. Areas within the Alquist-Priolo Earthquake Fault Zone are most likely to experience fault rupture within the planning area. If an epicenter of an earthquake occurs on a fault within the Alquist-Priolo Earthquake Fault Zone occurs, this area may also experience significant ground shaking.

Areas within the Alquist-Priolo Earthquake Fault Zone primarily include residential uses, with some open space and recreational uses included. The City of Seal Beach is required to regulate development projects within the Alquist Priolo Fault Zone with consideration for seismic risk, to ensure all construction and land divisions are safe for human occupancy. It is assumed fault rupture within the City is most likely to occur within the Alquist Priolo Fault Zone.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE Section 8. Seismic Hazard Assessment September 2025
Figure 8-4
Alquist-Priolo Earthquake Fault Zone
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan Alquist-Priolo Earthquake Fault Zone
61 ... 33
long Be a ch
J...,62
~
66 ~
or-----------,2 mnes -$
September 2025
Los Alamitos
- -,
Westminster Blvd
Seal Beach
Naval Weapons S!otion
Legend
,
I
I
I
~
I
I
\
I.
r - ,
I. - J
Seal Beach
Municipal Boundary
Critical Facilities
Westminste r
BolsoAve
Edinger Ave
Impacted Critical Facilities
Alquist Priolo Zone
Source: CA Dept. of Conservation, City of Seal Beach, Ori Projection: California State Plane Coordinate System Zone 6, NAD 83
Doto Sourced: 2017
Section 8. Seismic Hazard Assessment
As discussed above, several major are located within and near the City of Seal Beach. Table 8-4, Major Earthquake Faults of Particular Concern, identifies faults of concern within the region and last major ruptures. No significant fault rupture occurrences are noted within the planning area.

Table 8-4
Major Earthquake Faults of Particular Concern
Fault Name
Type of
Faulting
Last Major
Rupture
Slip
Rate
Interval
Between
Major
Ruptures
Probable
Magnitudes
Whittier Right-lateral
strike-slip
Holocene 2.5 to

3.0 mm/yr
Unknown 6.0 - 7.2 Mw
Elsinore Right-lateral
strike-slip
with some
reverse slip
18th
century A.D.

Roughly

4.0 mm/yr
Roughly
250 years

6.5 - 7.5 Mw
Palos Verdes Right-reverse Holocene 0.3 to

3.0 mm/yr
Unknown 6.0 to 7.0 Mw
Sierra Madre Reverse Holocene 0.36 to

4.0 mm/yr
Several
thousand
years

6.0 to 7.0 Mw
Newport/Inglewood Right lateral;
local reverse
slip
associated
with fault
steps
March 10,
1933,
Magnitude

6.4 0.6
mm/yr
Unknown 6.0 - 7.4 Mw
San Jacinto Right-lateral
strike-slip;
minor rightreverse
April 9,
1968,
Magnitude

6.5 7 to 17
mm/yr
Varies;
between
100 and
300 years

6.5 - 7.5 Mw
San Andreas Right lateral
strike-slip
April 18,
1906,
Magnitude

7.9 20 to 35
mm/yr
Varies;
average
140 years

6.8 – 8.0 Mw
Notes: Mm = millimeters, yr = year, Mw = Moment Magnitude Source: Southern California Earthquake Center, Significant Earthquakes and Faults, http://scedc.caltech.edu/significant/fault-index.html, accessed May 2, 2023.

As shown in Figure 8-2, Seismic Hazards, multiple regional major earthquakes over the past two decades have resulted in seismic ground shaking in the City of Seal Beach. The list below discusses major earthquakes that may have yielded some form of impact to the City:

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

8.1.3 PREVIOUS OCCURRENCES
Section 8. Seismic Hazard Assessment September 2025
• In 1933, an earthquake off the coast of Long Beach on the Newport-Inglewood fault measured an estimated 6.4 on the moment magnitude scale with an estimated Mercalli intensity of VIII. This earthquake killed 115 people, largely in southern Los Angeles County and Long Beach. Significant damage occurred in the City of Seal Beach including damaged roadway between Seal Beach and Bolsa Chica Gun Club.20 • The 1971 San Fernando earthquake in the San Gabriel Mountains measured 6.6 on the moment magnitude scale and XI on the Mercalli intensity scale, killing 64 people and causing extensive damage to freeway structures and buildings. Fault rupture occurred outside of the planning area, and no substantial damage or impacts were reported by the City.
• The Northridge earthquake in 1994 measured 6.7 on the moment magnitude scale with a Mercalli intensity of IX. It killed 57 people, caused over 5,000 injuries, and spawned multiple strong aftershocks. This earthquake caused an estimated $20 billion or more in damages across Los Angeles and Orange Counties. No major damage or impact to City. The I-10 freeway experienced collapse at several overpasses (La Cienega Boulevard, Venice Boulevard, Fairfax Avenue and Washington Boulevard) near the planning area, requiring a three-month closure to rebuild.

USGS, Long Beach, California, Earthquake March 10, 1933. Roadway between Seal Beach and Bolsa Chica Club.

Photo by W.W Bradley. https://www.usgs.gov/media/images/long-beach-california-earthquake-march-10- 1933-roadway-between-seal-beach-and-bolsa, accessed December 27, 2024.

No federally or state declared disasters relating to fault rupture or ground shaking have occurred including the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.
20 USGS, Earthquake in Southern California 90 Years Ago Changed the Way We Build, https://www.usgs.gov/news/featured-story/earthquake-southern-california-90-years-ago-changed-waywe-build, published March 7, 2023, accessed December 30, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan l , I I I '
-
September 2025 Section 8. Seismic Hazard Assessment
Fault Rupture & Ground Shaking
The southern California region is known to be seismically active, and thus the probability for future seismic hazard occurrences is considered highly likely. Given the historic seismic events in the region affecting the City of Seal Beach and presence of several local/regional faults, it is certain that such events will continue. The probability of a fault rupture/ground motion is considered highly likely. Highly likely means a 90 to 100 percent probability of occurrence in the next year or a recurrence interval of less than 1 year. The LHMP planning team assigned a high hazard planning consideration to the hazards and impacts associated with fault rupture/ground shaking based upon a highly likely probability and potential widespread expected impacts of future events. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that future earthquakes affecting the planning area will occur in the future and therefore felt “highly likely” best defined probability for this specific hazard.

The USGS Uniform Earthquake Rupture Forecast Version 3, released in 2017, provides a prospect of the likelihood each California region will experience a magnitude 6.7 or larger earthquake in the next 30 years; refer to Table 8-5, Likelihood of One or More Earthquakes Occurring in the Next 30 Years in Los Angeles Region by Fault. The Newport-Inglewood Fault, located within the planning area, shows lower probabilities for an earthquake greater than 6.7 M in the next 30 years compared to the San Andreas, San Jacinto, and Elsinore Fault. It is noted that while less likely, an earthquake on the Newport-Inglewood Fault would have the highest probability of fault rupture and strong ground shaking within the City.

Table 8-5
Likelihood of One or More Earthquakes Occurring in the Next 30 Years in Los Angeles Region by Fault
Magnitude Whittier
Fault
Elsinore
Fault
Newport/Ing
lewood San Jacinto San Andreas
M ≥ 6.7 1.17% 3.66% 0.95% 5.41% 19.21%
M ≥ 7.0 1.07% 1.82% 0.81% 5.39% 12.86%
M ≥ 7.5 0.58% 0.90% 0.42% 5.28% 10.21%
M ≥ 8.0 < 0.01% <0.01% -- 2.75% 3.24%
Notes:

1. M≥6.7 means magnitude greater than or equal to 6.7, and likewise for the other magnitude thresholds.

2. The 30-year period measured by this report is 2014 to 2044; a 30-year period is the typical duration of a homeowner mortgage.

3. Percentages for fault sections closest to the City.

Source: U.S. Department of the Interior and U.S. Geological Survey, https://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf, published March 2015, accessed July 23, 2024 The impact and potential losses of such an event reveal significant risk and could be devastating to not only the planning area but the entire Southern California region. With the highly concentrated county population of almost 10 million and the heavy use of local transportation City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

8.1.4 PROBABILITY OF FUTURE OCCURRENCES
Section 8. Seismic Hazard Assessment September 2025
infrastructure, a major earthquake could virtually shut down large portions of Southern California.

This would ultimately result in substantial impacts to the City.

Table 8-6, Possibility of Earthquakes in Los Angeles Region shows the average time between earthquakes in the various regions together with the likelihood of having one or more such earthquakes in the next 30 years (starting from 2014).21 Values listed in parentheses indicate the factor by which the rates and likelihoods have increased, or decreased, since the previous model (UCERF2). “Readiness” indicates the factor by which likelihoods are currently elevated, or lower, because of the length of time since the most recent large earthquakes (see text). These values include aftershocks. It is important to note that actual repeat times may be subject to a high degree of variability and will almost never exactly equal to the average listed here.

Table 8-6
Possibility of Earthquakes in Los Angeles Region
Magnitude (greater
than or equal to)
Average repeat
time (years)
30- year likelihood
of one or more
events
Readiness
5 1.4 (0.6) 100% (1.0) 1.0
6 10 (1.1) 96% (1.1) 1.0

6.7 40 (2.1) 60% (0.8) 1.1
7 61 (2.0) 46% (0.7) 1.2

7.5 109 (1.3) 31% (0.9) 1.3
8 532 (0.4) 7% (2.5) 1.3
Source: USGS, UCERF3: A New Earthquake Forecast for California’s Complex Fault System, https://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf, published March 2015, accessed July 23, 2024 Fault Rupture & Ground Shaking
Both fault rupture and ground shaking are caused by seismic activity, which is not correlated with climate change. Thus, fault ruptures or ground shaking are not more likely to occur as climate change impacts become more significant.

Liquefaction occurs when ground shaking causes saturated soils, primarily clay-free deposits such as sand or silt, to lose strength and act like a viscous fluid. Certain soils are more susceptible to liquefaction, particularly younger and looser sediment closer to the water table. According to FEMA, liquefaction causes three types of ground failure, as described below:
• Lateral spreads involve the lateral movement of large blocks of soil as a result of liquefaction of an underlying layer. They generally develop on gentle slopes, most commonly between 0.3 and 3 degrees. Horizontal movements commonly are as much as 10 to 15 feet. However, where slopes are particularly favorable, and the duration of 21 USGS, UCERF3: A New Earthquake Forecast for California’s Complex Fault System, https://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf, published March 2015, accessed July 23, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan

8.1.5 CLIMATE CHANGE

8.2 LIQUEFACTION

8.2.1 DESCRIPTION
September 2025 Section 8. Seismic Hazard Assessment
ground shaking is long, lateral movement may be as much as 100 to 150 feet. Lateral spread usually breaks up internally, forming numerous fissures and scarps. • Flow failures consist of liquefied soil or blocks of intact material riding on a layer of liquefied soil and are the most catastrophic type of ground failure caused by liquefaction.

They commonly move several feet and up to dozens of miles under certain conditions.

Flow failures usually form in loose saturated sands or silts on slopes greater than three degrees.
• Loss of bearing strength occurs when the soil supporting buildings or other structures liquefies. When large deformations occur, structures settle and tip. The general subsurface geometry required for liquefaction-caused bearing failures is a layer of saturated, cohesionless soil that extends from near the ground surface to a depth equal to about the width of the building.

The potential for liquefaction exists in areas susceptible to ground shaking with loose soils and/or shallow groundwater. Given the active faults in the region and the presence of geologically young, unconsolidated sediments, liquefaction is possible throughout the City. The California Geological Survey Seismic Hazard Zonation Program identifies and maps areas prone to liquefaction; refer to Figure 8-5, Liquefaction Hazard Zone.

Areas most at risk for liquefaction are primarily located within the vicinity of current or historical rivers or other drainages. Nearly the entire area of the City is susceptible to liquefaction except for portions of the Old Town area near the City’s geographic center. The extent of liquefaction would be highly specific to the type of ground shaking experienced, along with the epicenter location. It is assumed that liquefaction could occur as a result of ground shaking on the Newport Inglewood Fault, but could also be triggered by strong ground shaking from other faults within the southern California region.

Although not documented in detail, it is possible that liquefaction occurred in various areas throughout the City of Seal Beach during the 1933 Long Beach Earthquake.22 No federally or state declared disasters relating to fault rupture or ground shaking have occurred including the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Because there are several areas in the planning area that are located within an identified liquefaction zone, the LHMP Planning Team indicated the probability of future occurrences is considered highly likely. The FEMA hazard prioritization tool defines a highly likely probability as 90 to 100 percent probability in the next year or a recurrence interval of less than 1 year. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that future earthquakes affecting the planning area will occur in the future and therefore felt “highly likely” best defined probability for this specific hazard. 22 California Department of Conservation, The 1933 Long Beach Earthquake, https://www.conservation.ca.gov/cgs/earthquakes/long-beach, accessed December 30, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

8.2.2 LOCATION/EXTENT

8.2.3 PREVIOUS OCCURRENCES

8.2.4 PROBABILITY OF FUTURE OCCURRENCES
Section 8. Seismic Hazard Assessment September 2025
Figure 8-5
Liquefaction Hazard Zone
DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan Liquefaction tiazard Zone
long Beach
0 September 2025
Los Alamitos
Westminster
Westminster BIVO 35
BolwAve
32 Edinger Ave
Legend
r , Seal Beach
L J Municipal Boundary
G) Critical Facilities
G) Impacted Critical Facilities
- Liquefaction Hazard Zone
Source: CA Dept. of Conservation, USGS, Ci ty of Seal
Beach, Esri
Projection: California State Plane Coordinale System Zone 6, NAD 83
Doto Sourced: 2017
Section 8. Seismic Hazard Assessment
Because seismic activity is expected to continue in the southern California region, liquefaction should also be expected and anticipated as a secondary impact in the planning area from this hazard. It should be noted that liquefaction would most likely be triggered by a significant earthquake event within one of the fault zones close to or within the planning area. As previously noted, the Newport-Inglewood Fault has limited probability to produce a 6.7 Mw earthquake or greater in the next 30 years. This would then reduce the probability of future liquefaction as a result of an earthquake on this fault. Earthquakes are more probable to occur on the San Andres, San Jacinto, or Elsinore Faults. These three faults are located several miles from the planning area and depending on the epicenter and magnitude of the earthquake, may not be strong enough to trigger liquefaction within the jurisdiction.

Climate change may increase susceptibility to liquefaction. Climate change is likely to bring more severe rain events to southern California, increasing the amount of water saturation in loose soils.

Saturated soils are known to be at risk for liquefaction or ground failure in an earthquake. Thus, heavy periods of rain combined with a local earthquake with strong ground shaking could increase the likelihood of liquefaction potential.

To identify populations at risk for mapped seismic hazards, hazard data layers were overlaid and compared with City parcel data in Geographic Information Systems, ArcGIS. If a hazard layer either completely or partially overlapped with a parcel in the data layer, then the entire parcel is conservatively considered vulnerable in this analysis. In some instances, the hazard zone intersected with only small portions of individual properties. However, to provide a detailed understanding of risk and vulnerability as part of this hazard mitigation plan, these parcels (including all residential and non-residential development on the parcel, regardless of location) are considered vulnerable.

Fault Rupture and Ground Motion
Critical facilities located within the Alquist-Priolo Earthquake Fault Zone primarily include 2 water systems facilities. Critical facilities located within the City’s identified Alquist Priolo Zone have been listed in Table 8-7, Critical Facilities in the Alquist Priolo Zone. This data may not reflect recent discoveries of fault lines within the City of Seal Beach.

This analysis includes potential fault rupture along the Alquist Priolo Earthquake Fault Zone whereas the entirety of the City may be vulnerable to ground motion as seen in Figure 8-1, Shake Potential. Approximately 76 residential units are located within the Alquist-Priolo Earthquake Fault Zone. The number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that approximately 145 people reside in the Alquist Priolo Earthquake Fault Zone. Additionally, approximately 7,553 square feet of non-residential structures are located within the fault rupture hazard area. Refer to Table 8-8 Populations in the Alquist Priolo Zone for a summary of vulnerable residents, residential units, and non-residential buildings.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

8.2.5 CLIMATE CHANGE

8.3 VULNERABILITY ASSESSMENT

8.3.1 MAPPED HAZARDS VULNERABILITY ASSESSMENT
Section 8. Seismic Hazard Assessment September 2025
Table 8-7
Critical Facilities in the Alquist Priolo Zone
Map ID Name
Asset
Type
Community
Lifeline
Replacement
Value
3 2901 Edinger Ave - Sewer
lift pump station
Water
Systems
Water Systems $2,025,000
19 Stormwater Pump Station -
202 Seal Beach Blvd
(County owned)
Water
Systems
Water Systems Not Available
Table 8-8
Populations in the Alquist Priolo Zone
Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
145 76 7,553
As mentioned in Section 3.0, Community Profile, critical facilities #87 and #88 are bridges offering primary egress for the College Park West neighborhood. Critical facilities #87 and #88 are likely to face the greatest hazard vulnerability during seismic ground shaking events.

Critical facilities #87 and #88 are owned and operated by the City of Long Beach and Orange County Public Works/Orange County Flood Control District, respectively. As these assets are not owned by Seal Beach, the City possesses limited ability to dictate structural improvements or physical mitigation to each of these assets. However, the City is aware of the access challenges posed by these bridges in the event of failure due to seismic ground shaking, or a similar hazard event. In response, the City has identified specific mitigation actions to educate the local community about personal preparedness actions and alternative egress points within the neighborhood for emergency access.

Liquefaction
Critical facilities located within the liquefaction hazard include those that serve as transportation, water systems, safety and security, communications, and hazardous materials lifelines. In total, there are 72 vulnerable critical facilities located within the City’s liquefaction hazard zone.

Transportation, water systems, and safety and security are the primary asset types within the liquefaction hazard zone, however other types of critical facilities have also been identified as vulnerable. Critical facilities located within the City’s identified liquefaction hazard zone have been listed in Table 8-9, Critical Facilities in Liquefaction Zone.

Approximately 10,728 residential units are located within the liquefaction hazard zone. The number of vulnerable residential units multiplied by the average of 1.90 persons per household for Seal Beach indicates that approximately 20,384 people reside in the liquefaction hazard zone.

Additionally, approximately 3,099,408.6 square feet of non-residential structures are located within the liquefaction hazard area. Refer to Table 8-10, Populations at Risk for Liquefaction for a summary of vulnerable residents, residential units, and non-residential buildings.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 8. Seismic Hazard Assessment
Table 8-9
Critical Facilities in Liquefaction Zone
Map ID Name Asset Type
Community
Lifeline
Replacement
Value
1 3101 ½ N Gate Rd -
Potable water
reservoir, well and
pump station.

Water Systems Water Systems $2,425,000
2 2901 Edinger Ave -
Sewer lift pump
station
Water Systems Water Systems $1,050,000
4 Sewer lift pump
station - 800 Ocean
Ave
Water Systems Water Systems $1,050,000
5 Potable water well -
2700 North Gate Rd
Water Systems Water Systems $400,000
6 Potable water well -
3333 Bolsa Chica Rd
Water Systems Water Systems $400,000
7 Potable water well -
4307 Lampson Ave
Water Systems Water Systems $400,000
8 Sewer lift pump
station - 200 Seal
Beach Blvd
Water Systems Water Systems $1,050,000
10 Sewer lift pump
station - 2701 Seal
Beach Blvd
Water Systems Water Systems $1,050,000
11 Stormwater pump
station - 43 ½
Riversea Rd
Water Systems Water Systems $1,050,000
14 OCFA Fire Station 48 Government
Services
Safety and
Security,
Communications
$1,630,720
15 Seal Beach Marine
Safety Headquarters
Government
Services
Safety and
Security,
Communications
$3,129,060
16* OC-35 Import
Waterline Turnout
Transportation Transportation Not Available
17 Sewer lift station - 1st
St
Water Systems Water Systems $1,050,000
18 Stormwater Pump
Station - 202 Seal
Beach Blvd
(County owned)
Water Systems Water Systems Not Available
19 Bridge to Sunset
Aquatic Park (not
City-owned)
Water Systems Water Systems Not Available
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City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 8. Seismic Hazard Assessment September 2025
Map ID Name Asset Type
Community
Lifeline
Replacement
Value
20 OC San Regional
Wastewater
Collections Station
(not City-owned)
Water Systems Water Systems Not Available
21 Leisure World Water
Well (inactive)
Water Systems Water Systems Not Available
22 OC San Wastewater
Station - (3112
Yellowtail, Rossmoor)
Water Systems Water Systems Not Available
23 San Gabriel River
Bike Trail Entry Point
Transportation Transportation Not Available
24 Los Cerritos Wetlands
Restoration
(not City-owned)
Wetlands Safety and security Not Available
25 Hellman Oil Field
(not City-owned)
Oil Field Hazardous
Materials
Not Available
26 Stormwater Pump
Station (County
owned)
Water Systems Water Systems Not Available
27 Bridge 53C1998 –
San Gabriel River
(Local)
Transportation Transportation $16,324,000
28 Bridge 55C0041L –
Los Alamitos Channel
(Local)
Transportation Transportation $1,574,100
29 Bridge 55C0041R –
Los Alamitos Channel
(Local)
Transportation Transportation $1,574,100
30 Bridge 55C0042L -
Federal Storm
Channel
(Local)
Transportation Transportation $1,690,700
31 Bridge 55C0042R -
Federal Storm
Channel
(Local)
Transportation Transportation $1,906,410
32 Bridge 55C0075 -
Westminster Channel
(Local)
Transportation Transportation $5,281,980
33 Bridge 55C0104 –
Federal Storm
Channel
(Local)
Transportation Transportation $4,185,940
35 Bridge 55C0108 –
Bolsa Chica Channel
(Local)
Transportation Transportation $5,888,300
36 Bridge 55C0160 – Transportation Transportation $2,157,100 DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 8. Seismic Hazard Assessment
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Map ID Name Asset Type
Community
Lifeline
Replacement
Value
Bolsa Chica Channel
(Local)
37 Bridge 53 0060 –
San Gabriel River
(State)
Transportation Transportation $18,073,000
38 Bridge 53 0302L –
San Gabriel River
(State)
Transportation Transportation $9,969,300
39 Bridge 53 0302R –
San Gabriel River
(State)
Transportation Transportation $9,969,300
40 Bridge 53 1185 –
San Gabriel River
(State)
Transportation Transportation $35,563,000
41 Bridge 53 1737H –
San Gabriel River
(State)
Transportation Transportation $7,287,500
42 Bridge 55 0010 –
Anaheim Bay (State)
Transportation Transportation $16,673,800
43 Bridge 55 0065 –
Kitt Highway, US
Navy RR (State)
Transportation Transportation $6,879,400
44 Bridge 55 0310 –
Los Alamitos Channel
(State)
Transportation Transportation $9,328,000
45 Bridge 55 0334 –
Bolsa Chica Ditch
(State)
Transportation Transportation $67,045,000
46 Bridge 55 0347H –
Service Rd (State)
Transportation Transportation $378,950
47 Bridge 55 0412L –
Interstate 405 (State)
Transportation Transportation $19,822,000
48 Bridge 55 0412R –
Interstate 405 (State)
Transportation Transportation $11,660,000
49 Bridge 55 0413F –
Rte 405, 605, CONN,
RIV (State)
Transportation Transportation $44,891,000
50 Bridge 55 0415 –
E22 - N405 Connector
Ramp (State)
Transportation Transportation $131,175,000
51 Bridge 55 0426G –
S605 - S405
Connector (State)
Transportation Transportation $12,458,710
52 Bridge 55 0428G –
State Route 22 (State)
Transportation Transportation $26,818,000
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City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 8. Seismic Hazard Assessment September 2025
Map ID Name Asset Type
Community
Lifeline
Replacement
Value
53 Bridge 55 0441 –
Los Alamitos Channel
(State)
Transportation Transportation $15,158,000
54 Bridge 55 0471H –
Los Alamitos Channel
(State)
Transportation Transportation $1,107,700
55 Bridge 55 1100G –
Interstate 405 (State)
Transportation Transportation $44,308,000
56 Leisure World
Clubhouse 1
Community
Facility
Safety and Security Not Available
57 Leisure World
Clubhouse 2
Community
Facility
Safety and Security Not Available
58 Leisure World
Clubhouse 3
Community
Facility
Safety and Security Not Available
59 Leisure World
Clubhouse 4
Community
Facility
Safety and Security Not Available
60 Leisure World
Clubhouse 5
Community
Facility
Safety and Security Not Available
61 Leisure World
Clubhouse 6
Community
Facility
Safety and Security Not Available
62 Leisure World
Healthcare Center
Community
Facility
Health and Medical $3,000,695
65 North Seal Beach
Community Center
Community
Facility
Safety and
Security; Food,
Water, Shelter
$995,610
67 Seal Beach Tennis
Center
Community
Facility
Safety and Security $1,000,000
70 Police Substation Municipal
Services
Safety and
Security;
Communications
Not Available
72 Almond Park Public Park Safety and Security $750,000 73 Arbor Park Public Park Safety and Security $6,500,000 74 Aster Park Public Park Safety and Security $650,000
75 Bluebell Park Public Park Safety and Security $650,000 78 Edison Park Public Park Safety and Security $5,000,000 79 Eisenhower Park Public Park Safety and Security $700,000 81 Heather Park Public Park Safety and Security $800,000 82 Marina Park +
Community Center
Community
Facility
Safety and Security $500,000
83 Schooner Park Public Park Safety and Security $950,000 85 Beach Maintenance
yard
Government
Building
Hazardous
Materials
$4,064,100
87 College Park Drive
Box Culvert Bridge
Bridge Transportation Not Available
DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 8. Seismic Hazard Assessment
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Map ID Name Asset Type
Community
Lifeline
Replacement
Value
88 College Park Drive
Bridge over San
Gabriel River
Bridge Transportation Not Available
Table 8-10
Populations at Risk for Liquefaction
Residents at Risk Residential Units at Risk Non-Residential Area at Risk (sq. ft.)
20,384 10,728 3,099,408.6
Since the 2019 LHMP, development and land use has not substantially changed in the planning area. In the five years since the approval of the previous LHMP, only one significant housing development was identified in the City’s most recent 2021-2029 Housing Element: the construction of approximately thirty single family homes on a former Department of Water and Power (DWP) site at the intersection of Marina Drive and 1st Avenue. Other land use changes since the 2019 LHMP have been limited in nature, such as the addition of ADUs, and/or lot line adjustments. As these changes were minor in size and scale, vulnerability is not considered to have significantly changed in the past five years.

As development and land use in the planning area has not substantially changed since the 2019 LHMP, population trends have also remained relatively the same. United States Census Data reports a 2020 population of 25,232 and a 2023 population of 24,868, representing a 1.44 percent population decline. Generally, observed population decline in the planning area is associated with an overall aging population.

Looking forward, the City anticipates the majority of population growth would align with the 2021-2029 Housing Element, which proposes to accommodate the City’s Regional Housing Needs Allocation of 1,243 units largely at commercial sites which are proposed to be rezoned for mixed use. Based on anticipated growth and development, it is reasonable to assume that vulnerability to seismic hazards will increase over the 5-year planning period of this LHMP.As the entirety of the city is vulnerable to seismic hazards, any new development or population increase would overall increase vulnerability within the planning area Section 3-7 includes a detailed determination of Socially Vulnerable Populations (SVPs) within the planning area and characteristics that make those populations more vulnerable to hazards.

Seismic hazards can affect all SVPs including census tracts 995.09, 995.10, 995.02 and the Seal Beach Shores Mobile Home Park. Seal Beach Shores Mobile Home Park may be more severely impacted by ground shaking and liquefaction as the structures are not as foundationally stable and lack structural integrity.

City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE

8.3.2 CHANGES IN VULNERABILITY FROM PREVIOUS FIVE YEARS

8.3.3 CHANGES IN VULNERABILITY FOR FUTURE FIVE YEARS

8.4 SOCIALLY VULNERABLE POPULATIONS ASSESSMENT
Section 8. Seismic Hazard Assessment September 2025
Additionally, SVPs and other high-risk individuals exist throughout the planning area and may be present within seismic hazard zones despite a census tract’s social vulnerability classification.

Specific SVPs and high-risk individuals that may be present throughout the planning area include unemployed individuals, elderly populations age 65 and older, young populations under age 17, persons with disabilities, persons with high pollution burden, and tourists, seasonal visitors, and homeless populations. The primary concern for SVPs and other high-risk individuals in the City would be evacuation efforts, access to emergency services and supplies, and recovery.

Unemployed individuals may be more vulnerable to seismic hazards as they may be limited in financial resources to prepare for disasters, such as purchasing emergency supplies, securing adequate housing, or evacuating to safer areas with transportation. Additionally, unemployed individuals may have substandard housing, which may not be as resilient during an earthquake or liquefaction hazard event. These populations may also not have resources to seek medical care following an earthquake or liquefaction event. These social and economic disparities can further hinder their ability to recover, leaving them at greater risk of long-term displacement and financial hardship following a seismic event.

Young populations under age 17 may be more vulnerable to the impacts of seismic hazards due to being more susceptible to injuries and illnesses as their bodies are still developing. Younger children may also have limited mobility and awareness to evacuate in a timely manner during a disaster. Younger populations rely heavily on adults for protection, care, and decision-making; thus, if parents/guardians/caregivers are affected by a disaster, the child’s safety and well-being may be compromised. Lastly, a seismic hazard event can lead to school closures and displacement, which may disrupt children’s education and social development.

Elderly populations aged 65 and older are more vulnerable to seismic hazard events. Persons aged 65 or older often face several challenges when responding to an emergency, such as mobility challenges, health concerns, social isolation, barriers to transportation, and limited access to information or technology. In addition, there is often overlap between persons aged 65 or older and persons with a disability, as older adults experience increased prevalence of disabilities. This could include cognitive impairment, difficulties with independent living or hearing and vision problems. Lastly, this population may rely on caregivers for their well-being; thus, evacuation may be more difficult if this service is disrupted.

Similarly, persons with disabilities are highly vulnerable to seismic hazards due to mobility challenges, having difficulty evacuating quickly, or navigating through debris. This population may have more underlying health conditions that can be exacerbated by the stress and demands of a seismic event. There may be communication barriers to this population as emergency alerts and information may only be accessible in limited communication mediums. Seismic hazards can damage or destroy essential assistive devices such as wheelchairs, hearing aids, communication devices, and other medical technology. Additionally, persons with disabilities might rely on caregiving services which may be disrupted during seismic events and make it difficult to evacuate.

Persons exposed to areas with a high pollution burden are more vulnerable to seismic hazards for a variety of reasons. Seismic hazards can further exacerbate populations with high pollution DW1 DI lERA1:VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 8. Seismic Hazard Assessment
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8-26
burdens who are already exposed to high pollution levels and have weakened respiratory and cardiovascular systems. Communities with high pollution often face economic challenges, making it harder to prepare and recover from seismic hazard events. Lastly, persons dwelling in areas with a high pollution burden may have older, less resilient infrastructure, increasing the likelihood of damage during an earthquake or liquefaction event and ultimately leading to prolonged exposure to hazardous conditions.

Tourists, seasonal visitors, and homeless populations are particularly vulnerable during seismic hazard events due to their lack of familiarity with the area and lack of established support systems.

They may not be aware of evacuation routes or local emergency procedures, making it difficult for them to respond quickly. Additionally, they might not have access to timely information about disasters or the resources needed to cope with the aftermath. The City hosts multiple community events throughout the year and nearby Huntington Beach and Long Beach are expected to host sizeable events for the upcoming 2028 Olympic Games, indicting increased present and future vulnerability. These factors make SVPs throughout Seal Beach especially vulnerable to the impacts of seismic hazards.

Considerations for SVPs throughout the planning area were incorporated into the mitigation strategy in Section 11.0, Mitigation Strategy. Specifically, the LHMP Planning Team tailored Mitigation Actions P.1, P.8, 1.8, 5.4, and 5.9 to mitigate hazard impacts to SVPs including issues related to preparedness, evacuation, and access to emergency services.

City of Seal Beach Local Hazard Mitigation Plan DRi\1 DE,IBERA, IVE Section 8. Seismic Hazard Assessment September 2025

Fire is an integral component of many of California’s ecosystems.

However, uncontrolled fire hazards threaten lives, property, and natural resources and present a considerable risk to vegetation and wildlife habitats. Fires occur in wildland and urban areas. A wildland fire is a large destructive fire that can spread quickly over woodland or brush. A wildfire is an uncontrolled fire spreading through vegetative fuels. Wildfires can be caused by human error (such as campfires), intentionally by arson, by mechanical sources of ignition (such as heaters and generators), and by natural events (such as lightning). Wildfires often occur in forests or other areas with ample vegetation. In areas where structures and other human development meets or intermingles with wildland or vegetative fuels (referred to as the wildland urban interface), wildfires can cause significant property damage and present extreme threats to public health and safety.

There are three categories of interface fire: the classic wildland urban interface exists where well-defined urban and suburban development presses up against open wildland areas; the mixed wildland urban interface is characterized by isolated homes, subdivisions and small communities situated predominantly in wildland settings; and the occluded wildland urban interface exists where islands of wildland vegetation occur inside a largely urbanized area.

Certain conditions must be present for significant interface fires to occur. The most common conditions include hot, dry and windy weather; the inability of fire protection forces to contain or suppress the fire; the occurrence of multiple fires that overwhelm committed resources; and a large fuel load (dense vegetation). Once a fire has started, several conditions influence its behavior, including fuel topography, weather, drought and development.

SECTION 9: WILDFIRE AND URBAN FIRE

HAZARD ASSESSMENT

9.1 WILDFIRE AND URBAN FIRE

9.1.1 DESCRIPTION
Urban fires are fires that burn in developed areas, affecting or destroying private homes, commercial properties, parks, or public facilities. Wildfires have the potential to turn into urban fires if their trajectory takes them close enough to developed urban areas. Urban fires may start from a range of causes, such as downed power lines, a broken gas main, arson, poor disposal or management of toxic substances, or a lack of maintenance to wooden structures or facilities.

Southern California faces challenges with wildfire hazards from the increasing number of houses being built in the wildland-urban interface. Every year the growing population has expanded further and further into the hills and mountains, including into brush and forest lands. The increased “interface” between urban/suburban areas and the open spaces created by this expansion has produced a significant increase in threats to life and property from fires and has pushed existing fire protection systems beyond original or current design and capability.

During wildfire season, Southern California Edison (SoCal Edison) monitors weather conditions in fire prone areas. To prevent strong winds and extreme heat from causing fire accidents, SoCal Edison may proactively turn off power through activation of their Public Safety Power Shutoff (PSPS) program. Power outages as a secondary effect is discussed in detail in Section 6.0, Extreme Weather Hazard Assessment.

The Santa Ana winds can also further exacerbate wildfires. Santa Ana winds ranging from 45 to 100 mph push dry air from the inland deserts of California and the Southwest over the mountains that lie between these desert areas and coastal California. The Santa Ana winds also remove moisture in the air resulting in evaporation and dry vegetation.1 Dry vegetation acts as a fuel for wildfires to grow, with the strong Santa Ana winds driving wildfire spread.2 The California Department of Forestry and Fire Protection (CAL FIRE) prepares fire hazard severity maps including mapping areas of significant fire hazards based on fuels, terrain, weather, and other relevant factors. These zones, referred to as Fire Hazard Severity Zones (FHSZ), define the application of various mitigation strategies and influence how people construct buildings and protect property to reduce risk associated with wildland fires. While FHSZ do not predict when or where a wildfire will occur, zones identify where wildfire hazards could be more severe and therefore, are of greater concern for mitigation purposes. While some areas of Seal Beach may face susceptibility to the wildfire hazard based on certain conditions, no mapped wildfire hazard severity zones have been identified within the City. Figure 9-1, Orange County Mapped Wildfire Zones, identifies mapped wildfire hazards severity zones within Orange County.

Without mapped CAL FIRE hazard zones illustrating areas of heightened risk, this LHMP assumes wildfire risk affects the entirety of the planning area and concentrated risk within the City’s largest 1 Spectrum News 1, What are Santa Ana winds and do they cause wildfires?, https://spectrumnews1.com/ca/la-west/weather/2020/10/01/what-are-santa-ana-winds-and-do-theycause-wildfires-, published November 5, 2021, accessed December 27, 2024. 2 KTLA, What are Santa Ana winds and how do they impact fire season?, https://ktla.com/news/localnews/what-are-santa-ana-winds-and-how-do-they-impact-fireseason/#:~:text=Santa%20Ana%20winds%20are%20often%20strong%20enough%2C%20and%20being %20warm,perfect%20environment%20for%20a%20fire., published November 18, 2022, accessed December 27, 2024.

City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

9.1.2 LOCATION/EXTENT
Section 9. Wildfire and Urban Fire Hazard Assessment September 2025 open space areas, the Naval Weapons Station and Los Cerritos Wetlands. The City of Seal Beach contracts Orange County Fire Authority (OCFA) for any fire services. OCFA services include technical rescue, fire prevention, fire investigation, hazardous materials response, public information/education, paramedic, and ambulance transport services.3 The Naval Weapons Station is also supported by the Naval Weapons Station Seal Beach Federal Fire Department.

Mutual aid agreements exist between both agencies to share resources during emergency events.

Several policies are in place to prevent wildfires in the City, as Seal Beach has adopted the California Fire Code by reference into its municipal code. Specific requirements are in place regarding the use of welding equipment, cutting torches, tar pots, grinding devices, and other tools to prevent the ignition of a wildfire. The City also has a weed abatement program, which consists of monitoring for overgrowth of vegetation, and violations if vegetation if property owners do not manage vegetation overgrowth.

The magnitude and severity of wildfire and urban fire impacts can vary significantly, based on size, scale and location of the fire. Wildfires are not measured on a specific scale and are usually classified by size or impact. The size and severity of any fire depends on the availability of fuel, weather conditions, and topography, although wildfires in the wildland urban interface do not need to be significant in acreage to be damaging. Small fires in Orange County history have been known to cause significant property damage or loss of human life, highlighting the need for local fire crews to be prepared for wildfires that may develop from smaller, more isolated fire incidents.

Seal Beach's developed land is at risk of urban fires due to arson or malicious intent. Areas near infrastructure like power lines or gas transmission lines also face vulnerability, especially if these structures are damaged during weather or seismic events. Additionally, buildings with woodframe construction or flammable materials are more likely to catch fire. Gas stations throughout the City can also be sources of urban fires.

Fire protection challenges occur where development is located within and directly adjacent to wildland urban interface areas, thus increasing the extent of the hazard. As the number of structural features increases, so does the risk of incidence of fire. While no Very High Fire Hazard Severity Zones (VHFHSZs) have been identified within or in immediate vicinity of the City at this time, there is the potential for wildfire to spread quickly within the City if an ignition does occur. 3 City of Seal Beach, City of Seal Beach Fire Services, https://www.sealbeachca.gov/Departments/Fire, accessed January 9, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 9. Wildfire and Urban Fire Hazard Assessment Figure 9-1
Orange County Mapped Wildfire Zones
City of Seal Beach Local Hazard Mitigation Plan
Flre Hazard Sewrtty Zooes In Fire Ptotecllon Reoponslblllty state Reoponslblllty Area (SRA) Areas (no...SRA)
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(FRA)
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(LAA)
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Section 9. Wildfire and Urban Fire Hazard Assessment September 2025 No recent wildfire events have been reported within the City of Seal Beach or in areas immediately surrounding the City. While limited wildfire events have impacted the City and mapped wildfire areas have not presently been identified nearby, Seal Beach may face increased risk to wildfire under certain weather and environmental conditions.

Seal Beach has experienced a number of urban fires in recent history. Recent urban fire events affecting the City in the last five years have been summarized below:
• February 5, 2019 - Firefighters battled a multi-unit apartment fire in Seal Beach on the 800 block of Ocean Avenue. No injuries were reported in this incident.4 • May 26, 2019 - A two-alarm fire at a four-story apartment building on the 12400 block of Montecito Road was reported. The fire destroyed one unit, damaged four others, and displaced nine adults and two children. No injuries were reported in this incident.5 • January 20, 2020 - A massive third-alarm fire broke out at the Rossmoor Park Apartments in Seal Beach, forcing the displacement of over 30 people. Two people suffered from smoke inhalation, and another victim was burned in this incident.6 • June 19, 2022 - Firefighters battled an urban fire that fully engulfed the garage of a twostory home on the 1000 block of Crestview Avenue. No injuries resulted from this incident.7
No federally declared disasters related to wildfire or urban fire events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

Given the history of urban fire events in and near the City of Seal Beach, the probability of wildfires and urban fires occurring in the future is considered likely. A likely probability means a 10% to 90% probability of occurrence in the next year or a recurrence interval of 1 to 10 years. Seal Beach’s risk for personal injury, loss of life, and damage to property due to wildfire events is presently considered low given the lack of identified wildfire risk within the City. The City’s location near the coast, land maintenance on open space areas, and the City’s high water table due to its coastal location and the nearby San Gabriel River are factors contributing to Seal Beach’s low wildfire risk. Wildfire smoke as a secondary hazard is also considered to have a likely probability of occurrence in the future for similar reasons.

While the City has a limited history of major wildfire occurrences, there is a likelihood of future regional wildfire occurrence in surrounding areas. Outbreaks of wildfire may occur during the dry season or following periods of limited rainfall or drought. Large regional fires outside the City of 4 Ludwig, Ashley, Apartment Fire Doused In Seal Beach,
https://patch.com/california/losalamitos/apartment-fire-doused-seal-beach, accessed December 26, 2024. 5 Orange County Register, Fire at Seal Beach apartment complex displaces 11 residents, https://www.ocregister.com/2019/05/26/fire-at-seal-beach-apartment-complex-displaces-11-residents/, accessed December 26, 2024.
6 NBC 4 Los Angeles, 2 Hurt, Dozens Displaced Following Three-Alarm Blaze at Seal Beach Apartment Complex, https://www.nbclosangeles.com/news/2-hurt-dozens-displaced-following-three-alarm-blaze-atseal-beach-apartment-complex/2294936/, accessed December 26, 2024. 7 Long Beach Post, Crews douse garage fire at home near Gum Grove Park in Seal Beach, https://lbpost.com/news/garage-fire-seal-beach-video-gum-grove/, accessed December 26, 2024.

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9.1.3 PREVIOUS OCCURRENCES

9.1.4 PROBABILITY OF FUTURE OCCURRENCES
September 2025 Section 9. Wildfire and Urban Fire Hazard Assessment Seal Beach may result in wildfire smoke impacts depending on the severity, location, weather, and wind patterns of the fire. The LHMP planning team assigned a medium hazard planning consideration to the hazards and impacts associated with wildfire based upon a likely probability and the potential impacts of future events.

Climate change and global warming patterns cause an increase in temperatures, as well as more frequent and intense drought conditions. This is understood to be a contributing factor to more frequent and severe wildfires. As mentioned previously, the severity of wildfire is dependent on the amount of oxygen, heat, wind, relative humidity, and fuel. Most of these factors have direct or indirect ties to climate change and increased global temperatures.

A 2016 study identified the contribution of climate change to dry vegetation as it doubled the occurrence of large fires from 1984 and 2015 throughout the western United States.8 As climate change continues to increase global temperatures, drought conditions and excessive heat may become more common.9 Excessive heat and low humidity during the summer and fall months are likely to occur. This would increase dry vegetation, which could cause wildfires to move more quickly or spread into developed areas.

Regional wildfires will likely become an increased threat in the City of Seal Beach and surrounding areas. Wildfires release smoke, ash, and other particulate matter that degrade air and water quality. Thus, fires located in various parts of the City of Seal Beach and surrounding areas can negatively impact air and water quality throughout the planning area. As such, wildfire mitigation should consider the cumulative impacts associated with climate change.

Wildfire smoke poses a risk to the City of Seal Beach as a secondary hazard. Wildfire smoke is a mixture of gases and fine particles from burning trees, plants, buildings, and other materials.10 Fine particulate matter are particles smaller than 2.5 micrometers, which can be inhaled deeply into the lungs. When inhaled, fine particulate matter, also referred to as PM2.5, increases the risk of cardiovascular and respiratory problems. Additionally, wildfire smoke is a complex mixture that consists of other pollutants that have also been shown to lead to a variety of health effects.

Wildfire smoke distribution is affected by factors such as wind, weather, terrain, and fire heat intensity.11 Wind, particularly the Santa Ana winds, may affect wildfire smoke by either clearing 8 John, T. Abatzoglou, and A. Park William, “Impact of Anthropogenic Climate Change on Wildfire Across western US Forests,” Proceedings of the National Academy of Sciences, October 10, 2016. https://www.pnas.org/doi/10.1073/pnas.1607171113, accessed December 27, 2024. 9 National Oceanic and Atmospheric Administration, Wildfire Climate Connection, https://www.noaa.gov/noaa-wildfire/wildfire-climate-connection, accessed December 27, 2024. 10 Centers for Disease Control and Prevention, How Wildfire Smoke Affects Your Body, https://www.cdc.gov/air/wildfire-smoke/default.htm, published April 19, 2024, accessed December 27, 2024.
11 United States Environmental Protection Agency, Health Effects Attributed to Wildfire Smoke, https://www.epa.gov/wildfire-smoke-course/challenges-predicting-smoke-concentrations, updated February 2, 2024, accessed December 27, 2024.

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9.1.5 CLIMATE CHANGE

9.2 WILDFIRE SMOKE

9.2.1 DESCRIPTION
Section 9. Wildfire and Urban Fire Hazard Assessment September 2025 out an area or blow more smoke in or fan the flames which can therefore intensify the fire and worsen smoke.12 Intense heat generated by wildfire can drive smoke high into the air where it remains until it cools and beings to descend to ground level however it becomes more diluted and widespread. Terrain affects smoke concentrations by altering dispersal patterns.13 For example, as the sun warms mountain slopes, air is heated and rises, ultimately bringing smoke and fire with it from lower elevations. After sunlight passes, the terrain cools and the air descend, creating a down-slope airflow that can alter smoke dispersal.

Wildfire smoke is measured by the Air Quality Index (AQI). The AQI also focuses on health effects within a few hours or days after breathing polluted air. The EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide.14 The AQI is divided into six categories ranging from good to hazardous (refer to Table 9-1, Air Quality Index).

Table 9-1
Air Quality Index
Air Quality Index Category Associated Health Impacts
0 – 50 Good Air quality is satisfactory and poses little or no risk
51 – 100 Moderate Sensitive individuals should avoid outdoor activity as they may experience respiratory
symptoms
101 – 150 Unhealthy for
Sensitive Groups
General public and sensitive individuals in
particular are at risk to experience irritation and
respiratory problems
151 – 200 Unhealthy Increased likelihood of adverse effects and aggravation to the heart and lungs among general
public
201 – 300 Very Unhealthy General public will be noticeably affected.

Sensitive groups should restrict outdoor
activities.
301 – 500 Hazardous General public at high risk of experiencing strong irritations and adverse health effects. Should
avoid outdoor activities.

Source: U.S. Environmental Protection Agency, Air Data Basic Information, https://www.epa.gov/outdoorair-quality-data/air-data-basic-information, updated December 8, 2023, accessed August 10, 2024.

Health effects of wildfire smoke may be relatively minor, such as respiratory irritation, or may be serious and cause significant respiratory problems, heart failure, and death.15 Certain groups of people are more susceptible to the effects of wildfire smoke. Particularly vulnerable populations include unemployed individuals, elderly populations age 65 and older, young populations under age 17, persons with disabilities, persons with high pollution burden, and tourists, seasonal visitors, and homeless populations.
12 Ibid.
13 Ibid.
14 National Weather Service NOAA, Air Quality Index, https://www.weather.gov/safety/airquality-aqindex, updated 2024, accessed December 27, 2024.
15 United States Environmental Protection Agency, Health Effects Attributed to Wildfire Smoke, https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke, accessed December 27, 2024.

DW DI !ERA VE City of Seal Beach Local Hazard Mitigation Plan September 2025 Section 9. Wildfire and Urban Fire Hazard Assessment As there are no mapped hazard zones for wildfire smoke, the entire planning area could be impacted. The extent of wildfire smoke would depend heavily on the size and severity of the wildfire as well as weather and wind patterns. Larger wildfires generally create more significant wildfire smoke impacts that extend throughout the county. This may be exacerbated by strong winds, which would drive the smoke further throughout the planning area. Various health impacts are associated with wildfire smoke and poor air quality including coughing, phlegm, wheezing, difficulty breathing, eye irritation, heart failure, and death. Impacts would worsen with increased duration of exposure. Poor air quality and wildfire smoke may impact people even when indoors, leading to health impacts. However, vulnerable populations are most at risk of the health impacts associated with wildfire smoke.16
The nearest air quality monitoring stations to the City of Seal Beach are ARB #70033 in Signal Hill and #70110 in Long Beach.17
Previous occurrences of wildfire smoke impacting the City are very limited. However, on September 10, 2024, a smoke advisory was issued in Seal Beach due to the nearby Bridge, Line, Airport, and Roblar fires. Air quality during this time was classified as moderate, and residents were advised to limit outdoor exposure.18
No federally declared disasters related to wildfire smoke events have impacted the planning area within the last five years; refer to Table 4-4, Summary of Federally Declared Disasters Affecting the Planning Area.

As smoke can travel hundreds or thousands of miles, air quality can also be a problem from the wildfire itself.19 Predicting if air quality will improve or worsen can be difficult because of the unpredictable behavior of wildfires and factors such as wind, weather, and terrain.20 For example, a wind that usually clears out a valley could also blow more smoke in an area or even fan the flames therefore intensifying the fire and worsening smoke.

As previously mentioned in Section 9.1.4, the probability of wildfires and urban fires occurring in Seal Beach in the future is considered likely (10% to 90% probability of occurrence in the next year or a recurrence interval of 1 to 10 years). Given the limited history of wildfire events in and 16 United States Environmental Protection Agency, Health Effects Attributed to Wildfire Smoke, https://www.epa.gov/wildfire-smoke-course/health-effects-attributed-wildfire-smoke, accessed December 27, 2024.
17 California Air Resources Board, Air Monitoring Sites, https://ww2.arb.ca.gov/applications/airmonitoring-sites-interactive-map, updated 2024, accessed December 27, 2024. 18 Barnes, Rachel, Smoke Advisory Issued in Seal Beach Due to Multiple Nearby Fires, https://patch.com/california/losalamitos/smoke-advisory-issued-seal-beach-due-multiple-nearby-fires, accessed December 24, 2024.
19 United States Environmental Protection Agency, Challenges in Predicting Smoke Concentrations, https://www.epa.gov/wildfire-smoke-course/challenges-predicting-smoke-concentrations, updated February 2, 2024, accessed December 27, 2024.
20 Ibid.

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9.2.2 LOCATION/EXTENT

9.2.3 PREVIOUS OCCURRENCES

9.2.4 PROBABILITY OF FUTURE OCCURRENCES
Section 9. Wildfire and Urban Fire Hazard Assessment September 2025 near the City of Seal Beach, the probability of wildfire smoke occurring as a secondary hazard of wildfire in the future is considered likely. A likely probability means a 10% to 90% probability of occurrence in the next year or a recurrence interval of 1 to 10 years. While the LHMP Planning Team acknowledges this reoccurrence interval does not bear out historically, the team felt strongly that wildfires and wildfire smoke will likely affect the planning area in the future and therefore felt “likely” best defined probability for this specific hazard. The LHMP planning team assigned a medium hazard planning consideration to the hazards and impacts associated with wildfire smoke based upon a likely probability and the potential impacts of future events.

As climate change increases the intensity and frequency of wildfires, this will inevitably increase the amount of wildfire smoke. According to the Stanford Center for Innovation in Global Health, about one-third of all particulate matter pollution in the United States comes from wildfire smoke – wildfires that are more intense and common because of climate change.21 Wildfire and Urban Fire
Although CAL FIRE did not identify fire hazard severity zones within the City of Seal Beach, fires can occur in open spaces and parks throughout the City. This could include areas such as Gum Grove Park which includes highly flammable vegetation such as eucalyptus trees, Los Cerritos Wetlands, and areas of the Naval Weapon Station. Additionally, urban fires can occur anywhere within Seal Beach, which may spread throughout the City. Therefore, urban fires can affect the entirety of the City and yield potential impacts to critical facilities. This may inhibit critical facilities from functioning properly, acting as evacuation routes, and/or acting as shelters.

Wildfire Smoke
Depending upon the extent and magnitude of a wildfire event, major transportation routes could become severely congested or inaccessible. Evacuation efforts may face challenges due to limited exit routes available in the event of a wildfire, especially for socially vulnerable populations.

Wildfire smoke may cause emergency medical events that hinder the ability for residents and visitors to exit the hazard area, and smoke may be carried through the air to areas outside of the City, impacting the health of nearby populations. Wildfire impacts to critical facilities in the planning area such as local pump stations, reservoirs, water treatment facilities, and other utility stations could result in loss of power, gas, and water supply. Critical facilities designated as shelter locations may be damaged or inaccessible during a wildfire event, increasing the vulnerability of the local population to secondary hazards such as smoke inhalation. 21 Stanford Center for Innovation in Global Health, How climate change exacerbates air pollution (and its health impacts), https://globalhealth.stanford.edu/planetary-health-fellowship/how-climate-changeexacerbates-air-pollution-and-its-health-impacts.html/, published August 24, 2023, accessed June 28, 2024.

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9.2.5 CLIMATE CHANGE

9.3 VULNERABILITY ASSESSMENT

9.3.1 HAZARD VULNERABILITY ASSESSMENT
September 2025 Section 9. Wildfire and Urban Fire Hazard Assessment • I Since the 2019 LHMP, development and land use has not substantially changed in the planning area. In the five years since the approval of the previous LHMP, only one significant housing development was identified in the City’s most recent 2021-2029 Housing Element: the construction of approximately thirty single family homes on a former Department of Water and Power (DWP) site at the intersection of Marina Drive and 1st Avenue. Other land use changes since the 2019 LHMP occurred at the property level, such as the addition of ADUs, subdivisions, and/or lot line adjustments. As these changes were minor in size and scale, vulnerability is not considered to have significantly changed in the past five years.

As development and land use in the planning area has not substantially changed since the 2019 LHMP, population trends have also remained relatively the same. United States Census Data reports a 2020 population of 25,232 and a 2023 population of 24,868, representing a 1.44 percent population decline. Generally, observed population decline in the planning area is associated with an overall aging population.

Looking forward, the City anticipates the majority of population growth would align with the 2021-2029 Housing Element, which proposes to accommodate the City’s Regional Housing Needs Allocation of 1,243 units largely at commercial sites which are proposed to be rezoned for mixed use. These areas may be impacted by wildfire, urban fire, and wildfire smoke. Based on anticipated growth and development, it is reasonable to assume that vulnerability to wildfire/urban fire and wildfire smoke hazards will increase over the 5-year planning period of this LHMP.

Section 3-7 includes a detailed determination of Socially Vulnerable Populations (SVPs) within the planning area and characteristics that make those populations more vulnerable to hazards. As wildfires, urban fires, and wildfire smoke are not mapped, these hazards may affect SVPs across the planning area including census tracts 995.09, 995.10, 995.02 and the Seal Beach Shores Mobile Home Park.

Additionally, SVPs and other high-risk individuals exist throughout the planning area and may be present within wildfire/urban fire and wildfire smoke hazards zones despite a census tract’s social vulnerability classification. Specific SVPs and high-risk individuals that may be present throughout the planning area include unemployed individuals, elderly populations age 65 and older, young populations under age 17, persons with disabilities, persons with high pollution burden, and tourists, seasonal visitors, and homeless populations. The primary concern for SVPs and other high-risk individuals in the City would be evacuation efforts, access to emergency services and supplies, and recovery.

Unemployed individuals may be more vulnerable to wildfire/urban fire and wildfire smoke as they may be limited in financial resources to prepare for disasters, such as purchasing emergency supplies, securing adequate housing, or evacuating to safer areas by transportation. Additionally, unemployed individuals may have substandard housing, thereby potentially exposing them to wildfire smoke if their air filters are inadequate. These populations may not have resources to seek medical care following a wildfire/urban fire and wildfire smoke hazard event. These social and City of Seal Beach Local Hazard Mitigation Plan DRA DE,IBERA IVE

9.3.2 CHANGES IN VULNERABILITY FROM PREVIOUS FIVE YEARS

9.3.3 CHANGES IN VULNERABILITY FOR FUTURE FIVE YEARS

9.4 SOCIALLY VULNERABLE POPULATIONS ASSESSMENT
Section 9. Wildfire and Urban Fire Hazard Assessment September 2025 economic disparities can further hinder their ability to recover, leaving them at greater risk of long-term displacement and financial hardship following a wildfire/urban fire and wildfire smoke hazard event.