02E3379B4A — Santee City Council, May 28, 2025 (part 1 of 2)

CITY OF SANTEE
Planning & Building Department
Aubrey Glen Project
Class 32 CEQA Exemption Analysis

TABLE OF CONTENTS
I. PROJECT CHARACTERISTICS ......................................................................... 1 II. EXECUTIVE SUMMARY...................................................................................... 2 III. PROJECT DESCRIPTION ................................................................................... 2 Project Location.................................................................................................... 2 Existing Conditions and Surrounding Land Uses .................................................. 2 General Plan and Zoning ...................................................................................... 5 Project .................................................................................................................. 5 Project Construction ............................................................................................. 5 Project Conditions ................................................................................................ 7 IV. CLASS 32 CATEGORICAL EXEMPTION ANALYSIS...................................... 11 Criterion Section 15332(a): General Plan and Zoning Consistency.................... 12 Criterion Section 15332(b): Project Location, Size, and Context........................ 12 Criterion Section 15332(c): Endangered, Rare, or Threatened Species............. 13 Criterion Section 15332(d): Traffic, Noise, Air Quality, or Water Quality ............ 13 Criterion Section 15332(e): Utilities and Public Services..................................... 29 V. EXCEPTIONS TO CATEGORICAL EXEMPTIONS........................................... 29 Criterion 15300.2(a): Location ............................................................................ 29 Criterion 15300.2(b): Cumulative Impact............................................................. 30 Criterion 15300.2(c): Significant Effect................................................................ 30 Criterion 15300.2(d): Scenic Highway................................................................. 30 Criterion 15300.2(e): Hazardous Waste Sites ..................................................... 31 Criterion 15300.2(f): Historical Resources........................................................... 31 VI. REFERENCES CITED ....................................................................................... 32

FIGURES
1: Regional Location........................................................................................................... 3 2: Project Location on Aerial Photograph............................................................................ 4 3: Site Plan......................................................................................................................... 6 4: Construction Noise Contours.........................................................................................16 5: Vehicle Traffic Noise Contours ......................................................................................18 6: HVAC Noise Contours...................................................................................................21 TABLE OF CONTENTS (cont.)
TABLES
A: Project Trip Generation .................................................................................................14 B: Construction Noise Levels at Off-Site Receivers ...........................................................15 C: Vehicle Traffic Noise Levels ..........................................................................................17 D: HVAC Noise Levels at Off-Site Receivers .....................................................................20 E: Summary of Worst-case Construction Emissions ..........................................................24 F: Summary of Project Operational Emissions...................................................................25

APPENDICES
A: Traffic Analysis Intake Form
B: Noise Analysis
C: Operational Noise Evaluation of the Adjacent Car Wash at the Aubrey Glen Residential Development
D: Air Quality Analysis
E: Dranage Report
F: Storm Water Quality Management Plan

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I. PROJECT CHARACTERISTICS

1. Project Title:

Aubrey Glen Project Design Review (DR 2024-0005)

2. Lead Agency Name and Address:

City of Santee
Planning & Building Department
10601 Magnolia Avenue
Santee, CA 92071

3. Contact Person and Phone Number:

Sandi Sawa, MPL, AICP
Director of Planning and Building/City Planner
10601 Magnolia Avenue
Santee, CA 92071
(619) 259-4100 ext. 167; [email protected]

4. Project Location:
7737 Mission Gorge Road
Assessor’s Parcel Numbers: 386-701-02

5. Project Sponsor’s Name and Address:

Troy Friedeck
KB Home Coastal, Inc.
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131

6. Property Owner:

KB Home Coastal, Inc.
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131

7. Existing General Plan Designation:

High-Density Residential

8. Existing Zoning:

R-22 High-Density Residential (22-30 dwelling units per gross acre)

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II. EXECUTIVE SUMMARY
The project applicant, KB Home Coastal, Inc., has submitted documents for the proposed Aubrey Glen Project (project) for Design Review. The project site is bordered by Mission Gorge Road to the north, commercial and residential uses to the east, and high-density residential uses to the south and west, and therefore would be considered an “infill” project.

The project was previously approved under the City of Santee’s (City) Essential Housing Ordinance (EMP 2022-1). In conjunction with this Development Review application, the applicant is no longer seeking the designation as Essential Housing.

The California Environmental Quality Act (CEQA) analysis provided herein evaluates the consistency of the project with the exemption requirements for a Class 32 Categorical Exemption for infill development projects as set forth in State CEQA Guidelines Section 15332. Based on the information and conclusions set forth on the following pages, this CEQA analysis demonstrates the project’s consistency with the requirements for a Class 32 Categorical Exemption.

No additional environmental documentation or analysis is required.

III. PROJECT DESCRIPTION
Project Location
The project site is located at 7737 Mission Gorge Road (Assessor’s Parcel Number 386-701-02) in the city of Santee, California. The project site is located east of Aubrey Glen Drive and south of Mission Gorge Road. The 2.63-acre project site is currently developed with 11,700 square feet of vacant retail buildings surrounded by concrete and asphalt parking lots and minimal landscape planters. The project is bordered by Mission Gorge Road to the north, commercial and residential uses to the east, and high-density residential uses to the south and west. Figure 1 shows the regional location of the project. Figure 2 shows an aerial photograph of the project site and vicinity.

The site is served by San Diego Metropolitan Transit System (MTS) buses, with the nearest bus stop located at the intersection of Mission Gorge Road and West Hills Parkway, approximately 650 feet east of the project site.

Existing Conditions and Surrounding Land Uses
The existing setting of the project site is developed with vacant buildings surrounded by concrete and asphalt parking lots and minimal landscape planters. The project is bordered by Mission Gorge Road to the north, commercial and residential uses to the east, and high-density residential uses to the south and west.

The project site was previously used as a retail bottled water distribution facility. The site is abandoned and has not been used for the past ten years or more. There are no biological resources, endangered species or endangered species habitat on the site.

FIGURE 1
Regional Location
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San Diego
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Mission Tr ails
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Lakeside
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Ramona
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S A N D I E G O

C O U N T Y

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Chula Vista
San Diego
El Cajon
Encinitas
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Carlsbad
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Santee
Coronado
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Solana
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Del Mar
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USMC AIR

STATION

S A N D I E G O

C O U N T Y

M E X I C O
Imperial
Beach
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Chula Vista
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El Cajon
Encinitas
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FIGURE 2
Project Location on Aerial Photograph

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Image Source: NearMap (flown May 2024)
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Project Boundary
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General Plan and Zoning
The project would be consistent with the existing general plan land use designation and zoning designation of R-22 High-Density Residential (22 to 30 dwelling units per acre; Map ID no. 29; City of Santee 2022). Both the R-22 High-Density Residential land use and zoning designation are intended for residential development characterized by apartment and condominium buildings.

It is intended that this category utilize innovative site planning and building design (including three-story buildings) and incorporate on-site recreational amenities and open space. This designation has been applied in areas in close proximity to major community facilities and services, transit facilities, and major streets.

Project
The project would construct 52 residential dwelling units. Fourteen units would consist of attached residential, configured within seven, three-story duplex buildings, and each of the remaining 38 units would consist of three-story detached residential buildings. The residential units would average approximately 1,400 square feet in size, and the project would be consistent with the existing zoning designation of High-Density Residential R-22 (22 to 30 dwelling units per acre).

All 52 residential units would be configured with 3 bedrooms and 2.5 bathrooms, and 25 of these residential units would also be configured with a den. All 52 residential units would have private open space by way of patio/entry space and balcony/deck. Vehicular access would be provided via a driveway connecting to Aubrey Glen Drive. All 52 residential units would include a private two-car garage, providing for a total of 104 residential parking spaces. The project would also provide 15 on-site guest parking spaces. Overall, the project would provide a total of 119 parking spaces, which would exceed the City’s parking requirement of 2.25 parking spaces per unit.

Furthermore, the project would provide 12 off-site parking spaces along Aubrey Glen Drive that would be regulated by City right-of-way with signage. These 12 off-site parking spaces would not be exclusive to the project, and therefore are not included in the parking count. The project would also provide approximately 5,000 square feet of common open space with amenities that would be managed by a private homeowners association. Figure 3 shows the proposed site plan.

There is no natural vegetation that exists on-site, and the project would implement landscaping consistent with the requirements of the City’s Municipal Code Title 13, Section No. 13.36 (Landscaping) and Title 8, Section 8.06.070 (Protection of trees). Trash enclosures would be fenced and roofed. The project would include an on-site storm drain that would capture, detain, and treat site runoff prior to discharging to an existing storm drain system.

Project Construction
The project would be constructed over approximately 14 months and is anticipated to start in January 2025. Construction activities would consist of demolition of the existing buildings and parking lot areas, site preparation, grading, building construction, paving, and architectural coatings. Construction grading would be balanced so that no export or import would be required.

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Map Source: Summa Architecture
FIGURE 3
Site Plan

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Construction of the project would include the use of excavators, rubber-tired dozers, graders, tractors, loaders, backhoes, paving equipment, rollers, forklifts, cranes, generator sets, and air compressors. The nearest sensitive receptors are the residential uses to the east and high-density residential uses to the south and west.

Project Conditions
The following project conditions would be required. These measures would be incorporated as Conditions of Approval for the entitlement of the site and are typical for urban infill projects built on existing improved land within the city of Santee. Such measures taken to comply with building codes or to address common and typical concerns for new projects do not preclude the use of CEQA exemptions (Berkeley Hillside Preservation v. City of Berkeley (2015) 241 Cal. App.4th 943, 960-961). The following measures are standard conditions for similar development projects entitled in the past by the City:

Standard Project Condition No. 1 – Air Quality:

1. The construction contractor shall use construction equipment powered by California Air Resources Board (CARB) certified Tier 4, or newer, engines and haul trucks that conform to current U.S. Environmental Protection Agency truck standards.

2. During all grading and site preparation activities, the on-site construction superintendent shall ensure implementation of standard best management practices as required by the San Diego Air Pollution Control District (SDAPCD) Rule 55, Fugitive Dust Control.

3. During all grading and site preparation activities, the on-site construction superintendent shall ensure implementation of applicable California Department of Resources Recycling and Recovery (CalRecycle) Sustainable (Green) Building Program Measures, as specified on the CalRecycle website.

4. The project shall utilize high-efficiency equipment and fixtures consistent with the current California Green Building Standards Code and Title 24 of the California Code of Regulations. The project shall include the installation of infrastructure to make the proposed project solar-ready.

5. The project shall include the installation of infrastructure necessary for electric vehicle parking, as well as providing preferential parking for electric vehicles. The project shall provide bike parking on-site.

6. The project shall comply with the Santee Water Efficient Landscape Ordinance. The ordinance promotes water conservation and efficiency by imposing various requirements related to evapotranspiration rates, irrigation efficiency, and plant factors.

7. The project shall comply with Chapters 9.02 and 9.04 of the Santee Municipal Code that pertain to solid waste management and demolition and construction debris recycling.

8. In conformance with SDAPCD Rule 67.0.1, Architectural Coatings, the project shall use low volatile organic compound (VOC) paints.

9. The project shall not include wood burning stoves or fireplaces.

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Standard Project Condition No. 2 – Biological Resources:

1. In conformance with CEQA, the Migratory Bird Treaty Act and the California Fish and Game Code, brushing, clearing and/or grading shall not be allowed during bird breeding season (between January 15 and September 15). If vegetation is to be cleared during the breeding season, a qualified biologist shall perform a nesting bird survey within the proposed construction area and appropriately sized buffer no more than 72 hours prior to vegetation disturbance. If the planned vegetation disturbance does not occur within 72 hours of the nesting bird survey, then the area will be resurveyed. If nesting birds are found, then the qualified biologist will establish an adequate buffer zone (on a species-by-species, case-by-case basis) in which construction activities would be prohibited until the nest is no longer active. The size of the buffer zone is determined by the biologist based on the amount, intensity, and duration of construction and can be altered based on site conditions. If appropriate, as determined by the biologist, additional monitoring of the nesting birds may be conducted during construction to ensure that nesting activities are not disrupted.

2. All vehicles, equipment, tools, and supplies shall stay within the limits of the impact area.

3. Best management practices (BMP) features (e.g., silt fencing, straw wattles, and gravel bags) shall be installed where necessary to prevent and/or limit off‐site sedimentation runoff in accordance with an approved BMP plan.

4. Any planting stock to be brought onto the project site for landscaping shall be first inspected to ensure that it is free of pest species that could invade natural areas, including, but not limited to, Argentine ants (Linepithema humile), non-native fire ants (e.g., Solenopsis invicta), and other insect pests.

Standard Project Condition No. 3 – Geology/Soils:

The Construction Contractor shall ensure that construction of the project complies with the recommendations identified in the project-specific geotechnical investigation.

Recommendations related to general construction, seismic considerations, earthwork, foundations, building floor foundations, lateral earth pressures, corrosivity, drainage, storm infiltrations, exterior concrete, and masonry flatwork and paved areas shall be adhered to during all project design and construction.

Standard Project Condition No. 4 – Noise:

1. All construction plans shall include the following notes:
a) Operations shall conform to the City's Municipal Code Section 5.04.090. b) All equipment shall be equipped with properly maintained mufflers. c) The construction contractor shall place noise-generating construction equipment and locate construction staging areas at the greatest possible distance from sensitive uses whenever feasible during all project construction.

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d) The construction contractor shall use on-site electrical sources to power equipment rather than diesel generators where feasible.

2. All residential units located within 500 feet of the construction site shall be sent a notice regarding the construction schedule. A sign legible at a distance of 50 feet shall also be posted at the construction site. All notices and the signs shall indicate the dates and durations of construction activities, as well as provide a telephone number for the “noise disturbance coordinator.”

3. A “noise disturbance coordinator” shall be established. The disturbance coordinator shall be responsible for responding to any local complaints about construction noise. The disturbance coordinator shall determine the cause of the noise complaint (e.g., starting too early, bad muffler) and shall be required to implement reasonable measures to reduce noise levels.

4. The following note shall be incorporated into the project construction plan: “Control of Construction Hours. Construction activities occurring as part of the project shall be subject to the limitations and requirements of Section 5.04.090 of the City Municipal Code which states that construction activities may occur between 7:00 a.m. and 7:00 p.m. Mondays through Saturdays. No construction activities shall be permitted outside of these hours or on Sundays and holidays.”

5. Interior Noise: For the two units located closest to Mission Gorge Road, windows shall have a sound transmission class (STC) rating of 24 or higher. The STC ratings shall be specified on project building plans and shall be verified by the Director of Planning & Building, or designee, prior to the issuance of building permits.

Standard Project Condition No. 5 – Cultural - Tribal/Archaeological Monitor:

1. Prior to the start of ground-disturbing activities, the applicant shall retain a qualified archaeologist who meets the Secretary of the Interior’s Professional Qualifications Standards for Archaeology (U.S. Department of the Interior 1983) to carry out all mitigation related to cultural resources. The applicant shall also retain a Native American Monitor of Kumeyaay decent.

2. Prior to start of ground-disturbing activities, the qualified archaeologist shall conduct cultural resources sensitivity training for all construction personnel. Construction personnel shall be informed of the types of archaeological resources that may be encountered, and of the proper procedures to be enacted in the event of an inadvertent discovery of archaeological resources or human remains. The applicant shall ensure that construction personnel attend the training and sign an attendance acknowledgement form.

The applicant shall retain documentation demonstrating attendance.

3. The qualified archaeologist, or an archaeological monitor (working under the direct supervision of the qualified archaeologist), shall observe all initial ground-disturbing activities, including but not limited to brush clearance, vegetation removal, grubbing, grading, and excavation. The qualified archaeologist, in coordination with the applicant and the City, may reduce or discontinue monitoring if it is determined by the qualified archaeologist that the possibility of encountering buried archaeological deposits is low based on observations of soil stratigraphy or other factors. Archaeological monitoring shall be conducted by an archaeologist familiar with the types of archaeological resources that could be encountered within the project site. The archaeological monitor shall be

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empowered to halt or redirect ground-disturbing activities away from the vicinity of a discovery until the qualified archaeologist has evaluated the discovery and determined appropriate treatment (as prescribed below). The archaeological monitor shall keep daily logs detailing the types of activities and soils observed, and any discoveries. After monitoring has been completed, the qualified archaeologist shall prepare a monitoring report that details the results of monitoring. The report shall be submitted to the City and any Native American groups who request a copy. A copy of the final report shall be filed at the South Coastal Information Center.

4. The Native American Monitor shall be present for any pre-construction meeting and for all ground disturbing activities associated with the project. Should any cultural or tribal cultural resources be discovered, no further grading shall occur in the area of the discovery until the City Planner, or designee, with concurrence from the Native American Monitor, are satisfied that treatment of the resource has occurred. In the event that a unique archaeological resource or tribal cultural resource is discovered, and in accordance with Public Resources Code (PRC) Section 21083.2(b)(1), (2), and (4), the resource shall be moved and buried in an open space area of the project site, such as slope areas, which will not be subject to further grading activity, erosion, flooding, or any other ground disturbance that has the potential to expose the resource. The on-site area to which the resource is moved shall be protected in perpetuity as permanent open space. No identification of the resource shall be made on-site; however, the applicant shall plot the new location of the resource on a map showing latitudinal and longitudinal coordinates and provide that map to the Native American Heritage Commission (NAHC) for inclusion in the Sacred Lands File. Disposition of the resources shall be at the discretion of the City, but in accordance with the foregoing.

5. In the event of the unanticipated discovery of archaeological materials, all work shall immediately cease in the area (within 100 feet) of the discovery until it can be evaluated by the qualified archaeologist in consultation with the Native American Monitor.

Construction shall not resume until the qualified archaeologist has conferred with the applicant and the City on the significance of the resource.

6. If it is determined that the discovered archaeological resource constitutes a historical resource or a unique archaeological resource under CEQA, avoidance and preservation in place is the preferred manner of mitigation. Preservation in place may be accomplished by, but is not limited to, avoidance, incorporating the resource into open space, capping, or deeding the site into a permanent conservation easement. In the event that preservation in place is demonstrated to be infeasible and data recovery through excavation is the only feasible mitigation available, a Cultural Resources Treatment Plan shall be prepared and implemented by the qualified archaeologist in consultation with the applicant and the City that provides for the adequate recovery of the scientifically consequential information contained in the archaeological resource. The qualified archaeologist and the City shall consult with appropriate Native American representatives in determining treatment for prehistoric or Native American resources to ensure cultural values ascribed to the resources, beyond those which are scientifically important, are considered.

7. If human remains are encountered, all work shall halt in the vicinity (within 100 feet) of the discovery and the San Diego County Coroner will be contacted in accordance with PRC Section 5097.98 and Health and Safety Code Section 7050.5. The applicant and the City will also be notified. If the County Coroner determines that the remains are Native American, the NAHC will be notified in accordance with Health and Safety Code Section

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7050.5, subdivision (c), and PRC Section 5097.98 (as amended by Assembly Bill 2641).

The NAHC will designate a Most Likely Descendant (MLD) for the remains per PRC Section 5097.98. The MLD shall complete the inspection of the site within 48 hours of being granted access and shall provide recommendations for the treatment of the remains.

Until the landowner has conferred with the MLD, the applicant will ensure that the immediate vicinity where the discovery occurred is not disturbed by further activity, is adequately protected according to generally accepted cultural or archaeological standards or practices.

IV. CLASS 32 CATEGORICAL EXEMPTION ANALYSIS
The following analysis provides substantial evidence to support a conclusion that the project qualifies for an exemption under State CEQA Guidelines Section 15332 as a Class 32 urban infill development and would not have a significant effect on the environment.

Class 32 Categorical Exemption: Class 32 consists of projects characterized as in-fill development meeting the conditions described below:
(a) The project is consistent with the applicable general plan designation and all applicable general plan policies as well as with applicable zoning designation and regulations. (b) The proposed development occurs within city limits on a project site of no more than five acres substantially surrounded by urban uses.
(c) The project site has no value as habitat for endangered, rare or threatened species. (d) Approval of the project would not result in any significant effects relating to traffic, noise, air quality, or water quality.
(e) The site can be adequately served by all required utilities and public services.

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Criterion Section 15332(a): General Plan and Zoning Consistency Yes No
The project is consistent with the applicable general plan designation and all applicable general plan policies as well as with applicable zoning designation and regulations.

General Plan
The project would be consistent with the existing General Plan land use designation of R-22 High-Density Residential (22–30 dwelling units per gross acre). The R-22 High-Density Residential zoning designation is intended for residential development characterized by apartment and condominium buildings. It is intended that this category utilize innovative site planning and building design (including three-story buildings) and incorporate on-site recreational amenities and open space. This designation has been applied in areas in close proximity to major community facilities and services, transit facilities and major streets. The project would be consistent with the intent of the R-22 High-Density Residential General Plan land use designation.

Zoning
The project would be consistent with the existing zoning designation of R-22 High-Density Residential (22–30 dwelling units per gross acre). The R-22 High-Density Residential zoning designation is intended for residential development characterized by apartment and condominium buildings. It is intended that this category utilize innovative site planning and building design (including three-story buildings) and incorporate on-site recreational amenities and open space.

This designation has been applied in areas in close proximity to major community facilities and services, transit facilities and major streets. The project would be consistent with the intent of the R-22 High-Density Residential Zone.

The project would be consistent with the zoning regulations of the R-22 Zone. The maximum height limit for the R-22 Zone is 56 feet (four stories) and the proposed residential buildings would be three stories and would not exceed the height limit. The project meets all other zoning standards, including setbacks and parking. The setback requirements are 20 feet for the front setback, 10 feet for the side setback, and 10 feet for the rear setback. Each building/duplex setback would be 10 feet throughout, along with the community setback of 25 feet from Mission Gorge Road. The project would provide a total of 129 car parking spaces, which would exceed the City’s parking requirement of 2.25 parking spaces per unit. Landscaping would be provided within these setback areas as required by the City’s Zoning Ordinance.

Criterion Section 15332(b): Project Location, Size, and Context Yes No
The proposed development occurs within city limits on a project site of no more than 5 acres substantially surrounded by urban uses.

The project site is located on an approximately 2.63-acre site within the city of Santee and is surrounded by parcels developed with urban land uses and paved public streets. Therefore, the project would be consistent with State CEQA Guidelines Section 15332(b).

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Criterion Section 15332(c): Endangered, Rare, or Threatened Species Yes No
The project site has no value as habitat for endangered, rare or threatened species.

The project site consists of improved buildings, parking areas and driveways, with no undeveloped vegetation areas. The 2.63-acre project site is currently developed with 11,700 square feet of vacant retail buildings surrounded by concrete and asphalt parking lots and minimal landscape planters. The project is bordered by Mission Gorge Road to the north, commercial and residential uses to the east, and high-density residential uses to the south and west. No natural vegetation exists on the project site. There are no potentially jurisdictional aquatic resources on site. The San Diego River is located approximately 0.4 mile north of the site. The project site is surrounded by urban development and does not possess connectivity to substantial open space or habitat suitable to support endangered, rare, or threatened species.

The City determined that a Biological Resources Report was unnecessary for the subject property because it is fully developed with vacant retail buildings surrounded by concrete and asphalt parking lots, and there is no natural habitat on-site.

Due to its developed nature within an urbanized environment, the project site has no value as a wildlife corridor.

Therefore, the project site has no value as habitat for endangered, rare, or threatened species, and the project would be consistent with State CEQA Guidelines Section 15332(c).

Criterion Section 15332(d): Traffic, Noise, Air Quality, or Water Quality Yes No
Approval of the project would not result in any significant effects relating to traffic, noise, air quality, or water quality.

The analysis below describes the project effects for the resource topics in this criterion, organized as follows: traffic, noise, air quality, and water quality. As demonstrated in the following discussions, the project would not result in significant effects related to traffic, noise, air quality, or water quality and is consistent with Section 15332(d) of the State CEQA Guidelines.

Traffic
The following analysis is based on the Traffic Analysis Intake Form prepared by Linscott, Law & Greenspan, Engineers (Appendix A). Trip generation for the proposed 52 residential units was based on the Institute of Transportation Engineers’ (ITE) Trip General Manual. The ITE Land Use Code 215 (Single-Family Attached Housing) was used for project trip generation. This is considered the worst-case trip generation for the project. As shown in Table A, the project would generate 374 average daily trips (ADT).

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Table A: Project Trip Generation
Daily Trip Ends
(ADTs) a AM Peak Hour PM Peak Hour
Land Use
Description Size Rateb Volume Rate In:Out Split Volume Rate In:Out Split
Volume
In Out Total In Out Total
Multifamily
Housing (MidRise - Not
Close to Rail
Transit
52 DUc 7.2/ DU 374 0.48/ DU 31% : 69% 8 17 25 0.57/ DU 57% : 43% 17 13 30 TOTAL 374 8 17 25 17 13 30
aADT = average daily traffic. bRates are based on ITE Trip Generation Manual, 11th Edition - Land Use 215 (Single-Family Attached Housing) c DU = dwelling unit.

Completion of the Traffic Analysis Intake Form included an evaluation of whether the project would have the potential to result in impacts related to Vehicle Miles Traveled (VMT). The City of Santee Guidelines for Transportation Impact Studies identifies seven types of projects that can be screened out from the requirement for a VMT analysis. Projects consisting of less than 5 acres of land and generating fewer than 500 ADT would be considered small projects that screen out of the requirement for a VMT analysis. As shown in Table A above, the project would generate 374 ADT, which would be less than this screening criteria. Therefore, the project is screened out from a VMT analysis and is presumed to have a less than significant effect relating to traffic pursuant to Section 15332(d) of the State CEQA Guidelines.

Noise
The following analysis is based on the Noise Analysis prepared by RECON Environmental, Inc. (RECON) (Appendix B). The analysis was prepared in accordance with standards established in the City’s General Plan Noise Element and the City’s Municipal Code. The nearest sensitive receptors include residential uses adjacent to as close as 40 feet from the western project boundary, 40 feet from the southern project boundary, and 135 feet from the eastern project boundary.

Construction Noise. Noise level limits for construction activities are established in Section

5.04.090 of the City’s Municipal Code. These limits state that a notice must be provided to all owners and occupants within 300 feet of the project site if the construction equipment has a manufacturer’s noise rating of 85 decibels (dB) and operates at a specific location for 10 consecutive workdays. In addition, Section 5.04.090 of the City’s Municipal Code states that no construction equipment is permitted before 7:00 a.m. or after 7:00 p.m. on Mondays through Saturdays and at all times on Sundays and holidays. Project construction noise would be generated by diesel engine-driven construction equipment used for site preparation and grading, building construction, loading, unloading, and placing materials and paving. Diesel engine driven trucks also would bring construction materials to the site.

Construction equipment with a diesel engine typically generates maximum noise levels from 70 to 95 A-weighted decibel average one-hour equivalent noise level [dB(A) Leq] at a distance of 50 feet (Federal Highway Administration [FHWA] 2006 and 2008; Federal Transit Authority 2006). During construction, equipment moves to different locations and goes through varying load cycles, and there are breaks for the operators and for nonequipment tasks, such as measurement.

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Although maximum noise levels may be 70 to 95 dB(A) at a distance of 50 feet during most construction activities, hourly average noise levels from the grading phase of construction would be 85 dB(A) Leq at 50 feet from the center of construction activity when assessing the loudest pieces of equipment–dozer, excavator, and loader–working simultaneously. Noise associated with the construction of the project was modeled at a series of 15 receivers located at the adjacent properties. The results are summarized in Table B. Construction noise contours are shown in Figure 4. SoundPLAN data is provided as an attachment to Appendix B. Note that the project site has been previously disturbed and developed, and no blasting would be required.

Table B: Construction Noise Levels at Off-Site Receivers [dB(A) Leq] Receiver Land Use Designation Construction Noise Level
1 R14 (Medium-High Density Residential) 70
2 R14 (Medium-High Density Residential) 72
3 R14 (Medium-High Density Residential) 72
4 R14 (Medium-High Density Residential) 71
5 R7 (Medium Density Residential) 70
6 R7 (Medium Density Residential) 73
7 R7 (Medium Density Residential) 73
8 R7 (Medium Density Residential) 73
9 GC (General Commercial) 73
10 GC (General Commercial) 74
11 GC (General Commercial) 74
12 GC (General Commercial) 73
13 R7 (Medium Density Residential) 63
14 R7 (Medium Density Residential) 66
15 R7 (Medium Density Residential) 66
Source: Appendix B.
dB(A) Leq = A-weighted decibels equivalent noise level.

As shown in Table B, construction noise levels are anticipated to range from 63 to 74 dB(A) Leq at the adjacent properties. Although the existing adjacent uses would be exposed to construction noise levels that could be heard above ambient conditions, the exposure would be temporary.

The project would not require construction equipment that has a manufacturer’s noise rating of 85 dB or higher. In accordance with Section 5.04.090 of the City’s Municipal Code, construction activities would not occur before 7:00 a.m. or after 7:00 p.m. on Mondays through Saturdays and would not occur at any time on Sundays and holidays. Additionally, the project would be subject to Standard Project Condition No. 4 – Noise, items 1 through 4 (refer to Section III). Compliance with this condition would reduce construction noise impacts to less than significant. As construction activities associated with the project would comply with requirements of the Noise Abatement and Control Ordinance, impacts associated temporary increases in noise levels during construction would be less than significant.

On-Site Noise Compatibility. Noise and land use compatibility are regulated by the Noise Element of the City’s General Plan. Residential land uses are normally acceptable with noise levels up to 65 community noise equivalent level (CNEL), conditionally acceptable with noise levels from 65 to 70 CNEL, normally unacceptable with noise levels from 70 to 75 CNEL, and clearly unacceptable with noise levels above 75 CNEL.

FIGURE 4
Construction Noise Contours
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Image Source: NearMap (flown May 2024)
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M:\JOBS6\10174\common_gis\MXD\10174.1\Class32_exempt\fig4.mxd 07/16/2024 bma

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Vehicle traffic noise level contours across the project site were calculated using SoundPLAN.

These contours take into account the project area topography and the proposed buildings. Noise levels were also modeled at a series of first- through third-floor receivers located at the proposed buildings. Vehicle traffic noise contours and receiver locations are shown in Figure 5. The results are summarized in Table C below. SoundPLAN data is provided as an attachment to Appendix B.

Table C: Vehicle Traffic Noise Levels (CNEL)
Receiver 1st Floor 2nd Floor 3rd Floor
1 67 69 69
2 66 68 69
3 61 63 65
4 60 63 64
5 52 56 59
6 55 58 61
7 52 56 59
8 50 54 57
9 46 50 53
10 51 55 58
11 58 61 62
12 59 61 63
13 59 62 63
14 53 57 59
15 47 51 53
16 44 48 51
17 43 46 48
18 44 47 50
19 39 44 47
20 47 51 54
Source: Appendix B
CNEL = community noise equivalent level
As shown in Figure 5 and Table C above, exterior noise levels would be 65 CNEL or less at all receivers except at Receivers 1 and 2 on the northern side of the northernmost buildings closest to Mission Gorge Road. However, for Receivers 1 and 2, there are no proposed exterior use areas on the northern sides of those buildings. Patios would be located on the southern side of those buildings shielded from Mission Gorge Road. Exterior noise levels would not exceed the “normally acceptable” noise level limit of 65 CNEL at any proposed exterior use areas. Therefore, the project would not expose receivers to exterior noise levels in excess of standards established in the City’s General Plan, and impacts would be less than significant.

Interior noise levels can be reduced through standard construction techniques. When windows are closed, standard construction techniques provide various exterior-to-interior noise level reductions depending on the type of structure and window. According to the FHWA’s Highway Traffic Noise Analysis and Abatement Guidance, buildings with masonry façades and double-glazed windows can be estimated to provide a noise level reduction of 35 dB, while light-frame structures with double-glazed windows may provide noise level reductions of 20 to 25 dB (FHWA 2011).

FIGURE 5
Vehicle Traffic Noise Contours
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Image Source: NearMap (flown May 2024)
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M:\JOBS6\10174\common_gis\MXD\10174.1\Class32_exempt\fig5.mxd 01/16/2025 bma

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The interior noise level standard for residential uses is 45 CNEL. As shown in Table C above, with the exception of Receivers 1 and 2, exterior noise levels would range from 39 to 65 CNEL.

Standard light-frame construction would reduce exterior to interior noise levels by at least 20 dB.

This analysis conservatively assumes that standard construction techniques would achieve 20 dB exterior to interior noise reduction. Using this assumption, interior noise levels would be reduced to 45 CNEL or less.

For the two units located adjacent to Mission Gorge Road (Receivers 1 and 2), a more detailed evaluation of interior noise levels was conducted. The STC rating of windows, walls, and roofs is an integer value that rates how well a building component attenuates noise. The STC rating generally reflects the decibel reduction that a building component can achieve. Noise levels on the northern side of these units would be 69 CNEL. Therefore, because a noise reduction of up to 24 dB(A) is required to achieve interior noise levels of 45 CNEL or less, building components with an STC rating of up to 24 would be required. Standard walls and roofs typically have STC ratings greater than 40, and therefore would achieve the required noise reduction. In order to achieve an interior noise level of 45 CNEL or less in the two units closest to Mission Gorge Road, windows with an STC of 24 or greater would be required. The inclusion of windows with an STC of 24 in the two units closest to Mission Gorge Road shall be a project condition of approval (see Standard Condition No. 4, item 5). Therefore, the project would not expose receivers to interior noise levels in excess of standards established in the General Plan, and impacts would be less than significant.

Off-Site Vehicle Traffic Noise. The project would contribute traffic to the local roadways.

However, the project would not substantially alter the vehicle classifications mix on local or regional roadways, nor would the project alter the speed on an existing roadway or create a new roadway. Thus, the primary factor affecting off-site noise levels would be increased traffic volumes. While changes in noise levels would occur along any roadway where project-related traffic occurs, for noise assessment purposes, noise level increases are assumed to be greatest nearest the project site, as this location would represent the greatest concentration of project-related traffic. Noise impacts would be significant if, as a direct result of the project, (1) noise levels for any existing or planned development will exceed the noise levels considered compatible for that use in the General Plan, or (2) noise levels which already exceed the levels considered compatible for that use are increased by 3 dB or more.

Based on the ITE Trip Generation Manual 11th Edition, the project would generate 7.2 ADT per unit. The project proposes 52 units, which would generate a total of 374 ADT (see Appendix A).

A 3 dB increase in noise levels would occur when there is a doubling of traffic volumes on a roadway. Typically, a project would have to double the traffic volume on a roadway in order to have a significant direct noise increase of 3 dB or more or to be major contributor to the cumulative traffic volumes. The existing traffic volume on Mission Gorge Road is 12,877 ADT (see Appendix B, Table 3). Adding 374 ADT to Mission Gorge Road would increase noise levels by 0.1 dB, which would not be an audible change in noise levels. Therefore, operational roadway noise would not generate a substantial permanent increase in ambient noise levels for off-site noise sensitive land uses, and impacts would be less than significant.

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On-Site Noise. On-site generated noise is regulated by the City’s Municipal Code, Title 5 Health and Safety, Chapter 5.04 Noise Abatement and Control. Section 5.04.040 of the City’s Municipal Code states that “it is unlawful for any person to make, continue, or cause to be made or continued, within the limits of the City, any disturbing, excessive or offensive noise which causes discomfort or annoyance to reasonable persons of normal sensitivity residing in the area.” Section 5.04.040 also provides the following requirements for heating, ventilation, and air conditioning (HVAC) units:

4. Heating and Air Conditioning Equipment and Generators. a. It is unlawful for any person to operate or allow the operation of any generator, air conditioning, refrigeration or heating equipment in such manner as to create a noise disturbance on the premises of any other occupied property, or if a condominium, apartment house, duplex, or attached business, within any adjoining unit.
b. All generators, heating, air conditioning, or refrigeration equipment are subject to the setback and screening requirements in this code.

Additionally, in accordance with the Noise Element of the General Plan, the noise level threshold is 65 dB(A) Leq at the property line. Property line noise levels due to HVAC units were modeled using SoundPLAN. The modeling results are summarized in Table D. HVAC noise contours are shown in Figure 6. SoundPLAN data is provided as an attachment to Appendix B.

Table D: HVAC Noise Levels at Off-Site Receivers [dB(A) Leq] Receiver Land Use Designation HVAC Noise Level
1 R14 (Medium-High Density Residential) 44
2 R14 (Medium-High Density Residential) 46
3 R14 (Medium-High Density Residential) 45
4 R14 (Medium-High Density Residential) 43
5 R7 (Medium Density Residential) 41
6 R7 (Medium Density Residential) 56
7 R7 (Medium Density Residential) 51
8 R7 (Medium Density Residential) 50
9 GC (General Commercial) 51
10 GC (General Commercial) 53
11 GC (General Commercial) 51
12 GC (General Commercial) 48
13 R7 (Medium Density Residential) 39
14 R7 (Medium Density Residential) 42
15 R7 (Medium Density Residential) 42
Source: Appendix B
dB(A) Leq = A-weighted decibels equivalent noise level
HVAC = heating, ventilation, and air conditioning
FIGURE 6
HVAC Noise Contours
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Image Source: NearMap (flown May 2024)
Project Boundary 0 Feet 100 [
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M:\JOBS6\10174\common_gis\MXD\10174.1\Class32_exempt\fig6.mxd 11/13/2024 bma

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As shown in Table D, property line noise levels would range from 39 to 56 dB(A) Leq. This is a worst-case analysis that assumes all units would operate at 100 percent capacity (i.e., continuously without cycling off) during the daytime and nighttime hours. Noise levels would not exceed 65 dB(A) Leq. Noise at this level would not be considered a noise disturbance. The units would be operated in accordance with the requirements of the City’s Municipal Code.

Therefore, operational HVAC noise would not generate a substantial permanent increase in ambient noise levels for off-site noise sensitive land uses in excess of standards established in the City’s General Plan, and impacts would be less than significant.

A car wash is located adjacent to the project site to the northeast. The requirements of the City’s Municipal Code also apply to operations at the car wash. The car wash is temporarily closed but would potentially be reopened after renovations. An Operational Noise Evaluation of the car wash was conducted by Ldn Consulting, Inc. to determine estimated noise levels from existing and proposed car wash operations. The analysis concluded that the existing car wash operational noise levels comply with the noise standards at the property lines and no substantial permanent noise increase is anticipated (Appendix C). Therefore, the car wash would not expose on-site receptors to ambient noise levels in excess of standards established in the City’s General Plan, and impacts would be less than significant.

Air Quality
The following analysis is based on the Air Quality Analysis prepared by RECON (Appendix D).

The analysis of impacts is based on state and federal Ambient Air Quality Standards (AAQS) and assessed in accordance with the regional guidelines, policies, and standards and the SDAPCD.

The SDAPCD prepared the original 1991/1992 Regional Air Quality Strategy (RAQS) in response to requirements set forth in the California Clean Air Act (CAA). The California CAA requires areas that are designated state non-attainment areas for ozone, carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2) prepare and implement plans to attain the standards by the earliest practicable date. AAQS represent the maximum levels of background pollution considered safe, with an adequate margin of safety, to protect the public health and welfare. Six pollutants of primary concern were designated: ozone, CO, SO2, NO2, lead (Pb), particulate matter with a diameter of 10 microns and less (PM10), and particulate matter with a diameter of 2.5 microns and less (PM2.5). The project is located within the San Diego Air Basin (SDAB) and approximately 15 miles east of the Pacific Ocean. The SDAB is currently classified as a federal non-attainment area for ozone, and a state non-attainment area for ozone, PM10, and PM2.5.

Consistency with Applicable Air Quality Plan. Project consistency is based on whether the project would conflict with or obstruct implementation of the RAQS and/or applicable portions of the State Implementation Plan, which would lead to increases in the frequency or severity of existing air quality violations. The RAQS is the applicable regional air quality plan that sets forth the SDAPCD’s strategies for achieving the National AAQS and California AAQS. The SDAB is designated a non-attainment area for the federal and state ozone standard. Accordingly, the RAQS was developed to identify feasible emission control measures and provide expeditious progress toward attaining the standards for ozone. The two pollutants addressed in the RAQS are reactive organic gas (ROG) and oxides of nitrogen (NOX), which are precursors to the formation of ozone. Projected increases in motor vehicle usage, population, and growth create

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challenges in controlling emissions and, by extension, to maintaining and improving air quality.

The most recent 2022 RAQS and TCM was adopted in 2023 (SDAPCD 2022).

The growth projections used by the SDAPCD to develop the RAQS emissions budgets are based on the population, vehicle trends, and land use plans developed in General Plans and used by the San Diego Association of Governments (SANDAG) in the development of the regional transportation plans and sustainable communities strategy. As such, projects that propose development that is consistent with the growth anticipated by SANDAG’s growth projections and/or the General Plan would not conflict with the RAQS. In the event that a project would propose development that is less dense than anticipated by the growth projections, the project would likewise be consistent with the RAQS. In the event a project proposes development that is greater than anticipated in the growth projections, further analysis would be warranted to determine if the project would exceed the growth projections used in the RAQS for the specific subregional area.

The project site was evaluated as a part of the City’s Housing Element Rezone Program Implementation Environmental Impact Report (EIR) (City of Santee 2022). The project site was previously designated as General Commercial (GC) and was rezoned to High-Density Residential R-22 (22 to 30 dwelling units per acre). The Housing Element Rezone Program was developed prior to updates to the 2022 RAQS. Therefore, growth forecasting in the 2022 RAQS update utilized the previous General Commercial land use designation. Assuming a typical floor area ratio of 0.2 for commercial development in the City, the 2.63-acre site could have been developed with approximately 29,000 square feet of commercial uses. The SANDAG trip generation rate for a neighborhood shopping center use is 120 trips per 1,000 square feet and the SANDAG trip generation rate for a standard commercial office is 20 trips per 1,000 square feet (SANDAG 2002).

Using these rates, a hypothetical retail project would have generated 3,480 ADT and a hypothetical office project would have generated 580 ADT. As discussed in the transportation section above, the project would generate 374 ADT, which would be less than the trips generated by the hypothetical retail and office projects described above. Therefore, the project would generate fewer emissions than what is accounted for in the RAQS and would not exceed the growth assumptions used in the RAQS, and impacts would be less than significant.

Criteria Pollutants. The region is classified as an attainment area for all criterion pollutants except ozone, PM10, and PM2.5. The SDAB is a non-attainment area for the 8-hour federal and state ozone standards. Ozone is not emitted directly but is a result of atmospheric activity on precursors. NOX and ROG are known as the chief “precursors” of ozone. These compounds react in the presence of sunlight to produce ozone. PM2.5 includes fine particles that are found in smoke and haze and are emitted from all types of combustion activities (motor vehicles, power plants, wood burning, etc.) and certain industrial processes. PM10 includes both fine and coarse dust particles, and sources include crushing or grinding operations and dust from paved or unpaved roads.

The City has not adopted air quality significance thresholds. The SDAPCD also does not provide specific numeric thresholds for determining the significance of air quality impacts under CEQA.

However, the SDAPCD does specify Air Quality Impact Analysis trigger levels for new or modified stationary sources (SDAPCD Rules 20.1, 20.2, and 20.3). The SDAPCD does not consider these

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trigger levels to represent adverse air quality impacts; rather, if these trigger levels are exceeded by a project, the SDAPCD requires an air quality analysis to determine if a significant air quality impact would occur. While these trigger levels do not generally apply to mobile sources or general land development projects, for comparative purposes these levels are used to evaluate the increased emissions that would be discharged to the SDAB if the project were approved.

As shown in Table E, project construction would not exceed the applicable regional emissions thresholds, which are designed to provide limits below which project emissions would not significantly change regional air quality. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, items 1 through 3, 7, and 8 (refer to Section III). Therefore, project construction would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard, and impacts would be less than significant.

Table E: Summary of Worst-case Construction Emissions
(pounds per day)
Construction
Pollutant
ROG NOX CO SOX PM10 PM2.5
Demolition 2 23 21 <1 2 1
Site Preparation 3 32 31 <1 9 5
Grading 2 16 19 <1 4 2
Building Construction 1 11 15 <1 1 <1
Paving 1 6 10 <1 <1 <1
Architectural Coatings 35 1 1 <1 <1 <1
Maximum Daily Emissions 35 32 31 <1 9 5
Significance Threshold 250 250 550 250 100 67
Source: Appendix D.

Long-term emissions of regional air pollutants occur from operational sources. As shown in Table F, the project’s daily operational emissions would not exceed the applicable regional emissions thresholds for any pollutant. These thresholds align with attainment of the National Ambient Air Quality Standards (NAAQS) which were developed to protect the public health, specifically the health of “sensitive” populations, including asthmatics, children, and the elderly.

Consequently, project operation would not impact any sensitive populations. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, items 4 through 9 (refer to Section III). Therefore, project operation would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard, and impacts would be less than significant.

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Table F: Summary of Project Operational Emissions (pounds per day) Pollutant
ROG NOX CO SOX PM10 PM2.5
Area Sources 1 1 8 <1 2 <1
Energy Sources 3 <1 3 <1 <1 <1
Mobile Sources <1 <1 <1 <1 <1 <1
Total 4 1 11 <1 2 <1
Significance Threshold 250 250 550 250 100 67
Source: Appendix D.

Sensitive Receptors. Sensitive land uses include schools and schoolyards, parks and playgrounds, day care centers, nursing homes, hospitals, and residential communities. The nearest sensitive receptors include residential uses adjacent to as close as 40 feet from the western project boundary, 40 feet from the southern project boundary, and 135 feet from the eastern project boundary.

Carbon Monoxide Hot Spots
Localized CO concentration is a direct function of motor vehicle activity at signalized intersections (e.g., idling time and traffic flow conditions), particularly during peak commute hours and meteorological conditions. The SDAB is a CO maintenance area under the federal CAA. This means that SDAB was previously a non-attainment area and is currently implementing a 10-year plan for continuing to meet and maintain air quality standards.

The Bay Area Air Quality Management District (BAAQMD) developed a screening threshold in their 2022 CEQA Guidelines (BAAQMD 2022). These screening criteria are considered applicable in the SDAB because the San Francisco Bay Air Basin and the SDAB have the same CO maintenance designations. If the following screening criteria are met, operation of a project would result in less than significant impacts related to CO:
• The project would be consistent with an applicable congestion management program established by the County congestion management agency for designated roads or highways, the regional transportation plan, and local congestion management agency plans.
• Project-generated traffic would not increase traffic volumes at affected intersections to more than 44,000 vehicles per hour.
• Project-generated traffic would not increase traffic volumes at affected intersections to more than 24,000 vehicles per hour where vertical and/or horizontal mixing is substantially limited (e.g., tunnel, parking garage, bridge underpass, natural or urban street canyon, below-grade roadway).

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Based on SANDAG daily roadway segment traffic projections (SANDAG 2022) and a peak hour volume equal to approximately 10 percent of the daily roadway segment volume, roadways in the vicinity of the project carry significantly less than both the 44,000 vehicles per hour and 24,000 vehicles per hour screening levels identified above. Therefore, the project’s traffic contribution of 374 ADT would not generate a CO hot spot that could expose sensitive receptors to substantial pollutant concentration, and impacts would be less than significant.

Diesel Particulate Matter – Construction
Construction of the project and associated infrastructure would result in short-term diesel exhaust emissions from on-site heavy-duty equipment. Construction of the project would result in the generation of diesel-exhaust diesel particulate matter (DPM) emissions from the use of off-road diesel equipment required for site grading and excavation, paving, and other construction activities and on-road diesel equipment used to bring materials to and from the project site.

Generation of DPM from construction projects typically occurs in a single area for a short period.

Construction is anticipated to last for approximately 14 months based on default CalEEMod phase durations. The dose to which the receptors are exposed is the primary factor used to determine health risk. Dose is a function of the concentration of a substance or substances in the environment and the extent of exposure that person has with the substance. Dose is positively correlated with time, meaning that a longer exposure period would result in a higher exposure level for the Maximally Exposed Individual. The risks estimated for a Maximally Exposed Individual are higher if a fixed exposure occurs over a longer period of time. According to the Office of Environmental Health Hazard Assessment (OEHHA), health risk assessments, which determine the exposure of sensitive receptors to toxic emissions, should be based on a 30-year exposure period; however, such assessments should be limited to the period/duration of activities associated with the project (OEHHA 2015). Thus, if the duration of proposed construction activities near any specific sensitive receptor were 14 months, the exposure would be less than 4 percent of the total 30-year exposure period (1.17 years divided by 30 years) used for health risk calculation. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, item 1 which would reduce construction equipment DPM emissions (refer to Section III). Because construction of the project would be short term (14 months) and the amount of heavy equipment required would be minimal, project construction would not expose nearby residents to substantial pollutant concentrations, and impacts would be less than significant.

Diesel Particulate Matter – Operation
The CARB handbook indicates that siting new sensitive land uses within 500 feet of a freeway or urban roads with 100,000 or more vehicles per day should be avoided when possible. The roadways within 500 feet of the project site include Aubrey Glen Drive and Mission Gorge Road.

Based on SANDAG daily roadway traffic projections, volumes on these roadways are projected to be well less than 100,000 vehicles per day (SANDAG 2022). Therefore, the project would not expose sensitive receptors to substantial pollutant concentrations associated with diesel particulate matter during operation, and impacts would be less than significant.

Odors. Construction equipment may generate some nuisance odors. Sensitive receptors near the project site include residential uses; however, exposure to odors associated with project construction would be short term and temporary in nature (14 months), and only a minimal amount

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of construction equipment would be required. The project does not propose any operational uses that are typically associated with odor complaints, nor it does not propose any uses or activities that would result in potentially significant operational-source odor impacts. Therefore, the project would not generate other emissions (such as those leading to odors) adversely affecting a substantial number of people, and impacts would be less than significant.

Water Quality
The following analysis is based on the Storm Water Quality Management Plan (Appendix E) and Drainage Report (Appendix F) prepared by RICK Engineering.

Water Quality Standards. In the existing condition, the project site generally drains in a northerly direction to a single point of comparison (POC-1) located on the northeastern side of the property along Mission Gorge Road. Off-site flows that traverse the project site begin to the south and drain north to a detention vault and then to a water quality basin. Flows are discharged from the basin onto the project site and then are collected by an existing brow ditch and conveyed to Mission Gorge Road. Additional off-site flows begin south of the project site and drain north to a cobble-lined swale, which then discharge through a curb opening onto Aubrey Glen Drive, followed by collection in a v-gutter, which are then conveyed north to an existing curb inlet on Mission Gorge Road (see Appendix E).

Drainage patterns in the post-project condition would be similar to those found in the existing condition. Off-site flows that traverse the project site would be collected by a proposed clean water line storm drain system and conveyed north to the edge of the property boundary. The clean water line would route off-site flows that are already treated via the water quality basin south of the project. To ensure appropriate sizing, the clean water line would be sized and designed for the unmitigated 100-year storm event rather than the mitigated 100-year storm event. Flows from the south would be captured in a proposed type-F catch basin on the southern property boundary and routed to the clean water line that flows north to the property frontage (see Appendix E).

Drainage on-site would be collected by curb inlets and grate inlets and conveyed by a proposed dirty water storm drain system to the northern property boundary. The dirty water line would be treated via proposed modular wetland system (MWS), then confluence with the clean water line prior to discharge from the project site. Additional drainage along the northern portion of the project site would be collected by a grate inlet and treated by a biofiltration basin, then joined with flows discharging the site to Mission Gorge Road. The proposed MWS and biofiltration basin would be designed consistent with the requirements of the City of Santee Best Management Practices Design Manual, which would effectively treat all runoff before being discharged from the site (see Appendix F). Therefore, the project would not violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or ground water quality, and impacts would be less than significant.

Groundwater Supply and Recharge. The project would obtain its water supply from the Padre Dam Municipal Water District and would not use groundwater supply for any purpose. The project would convert the existing configuration of vacant retail buildings surrounded by concrete and asphalt parking lots to a multi-family residential development with landscaped areas. These changes would decrease the amount of impervious area on-site from 101,930 square-feet in the

Page 28 ends

pre-project condition to 82,677 square feet in the post-project condition, thereby increasing the amount of land available for groundwater recharge. Furthermore, water would continue to infiltrate through undeveloped land further north, south, and east of the project site, and throughout the groundwater basin. Therefore, the project would not substantially decrease groundwater supplies or interfere with groundwater recharge, and impacts would be less than significant.

Drainage. As described in the discussion of water quality standards above, drainage patterns in the post-project condition would be similar to those found in the existing condition. The Drainage Report prepared for the project documented that project would reduce flow rates under the 10-, 50-, and 100-year storm events as follows:
• Reduce the 10-Year flow rate from 30.5 cubic feet per second (cfs) in the existing condition to 23.4 cfs in the post-project condition.
• Reduce the 50-Year flow rate from 42.0 cfs in the existing condition to 32.1 cfs in the postproject condition.
• Reduce the 100-Year flow rate from 44.0 cfs in the existing condition to 33.8 cfs in the postproject condition (see Appendix F).

Therefore, the project would not result in substantial erosion or siltation on- or off-site, substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site, create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff; or impede or redirect flood flows, and impacts would be less than significant.

Flooding and Hazards. Review of Figure 4.8-2 of the City of Santee Housing Element Rezone Program Environmental Impact Report determined that the project site is not located within the 100year or 500-year flood hazard area. The project site is located approximately 17 miles inland from the coast. The risk of tsunami is negligible due to the distance from the ocean and high elevation. There would be no risk from a seiche, as the site is not located near a large body of water, such as a lake. Therefore, the project would not risk the release of pollutants due to project inundation associated with flood hazards, tsunami, or seiche zones. No impact would occur.

Water Quality and Groundwater Plans. As described in the discussion of water quality standards above, the project would utilize a MWS and biofiltration basin that would be designed consistent with the requirements of the City of Santee Best Management Practices Design Manual, which would effectively treat all runoff before being discharged from the project site. As described in the discussion of groundwater supply and recharge above, the project would not use groundwater supply for any purpose and would decrease the amount of impervious area on-site, thereby increasing the amount of land available for groundwater recharge. Therefore, the project would not conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan, and impacts would be less than significant.

Page 29 ends

Criterion Section 15332(e): Utilities and Public Services Yes No
The site can be adequately served by all required utilities and public services.

The project would include connections to utilities such as sewer, water, electrical, gas, and telecommunications within the Aubrey Glen Drive right-of-way. Overhead electrical facilities along the project site frontage would be relocated underground where feasible. The northern portion of the project site proposes a 30-foot easement for road and utility purposes. The south side of the project site includes an existing 20-foot sewer easement and a proposed 5-foot-wide easement to San Diego Gas and Electric (SDG&E).

All on-site utilities would be designed in accordance with applicable codes and current engineering practices. There would be no significant environmental effects specifically related to the installation of utility connections that are not encompassed within the project’s construction and operational footprints, and therefore already identified, disclosed, and subject to all applicable local, State, and federal regulations specified above. Therefore, the project site can be adequately served by all required utilities and public services, and the project would be consistent with State CEQA Guidelines Section 15332(e).

V. EXCEPTIONS TO CATEGORICAL EXEMPTIONS
Even if a project is ordinarily exempt under any of the potential categorical exemptions, State CEQA Guidelines Section 15300.2 provides specific instances where exceptions to otherwise applicable exemptions apply. The following section addresses whether any of the exceptions to the CEQA exemption apply to the project, consistent with State CEQA Guidelines Section 15300.2:

Criterion 15300.2(a): Location
Yes No
Is there an exception to the exemption for the project due to its location in a particularly sensitive environment, such that the project may impact an environmental resource of hazardous or critical concern where designated, precisely mapped, and officially adopted pursuant to law by federal, state, or local agencies? This exception applies only to CEQA exemptions under Classes 3, 4, 5, 6, or 11. Since the project would qualify as a Class 32 urban infill exemption, this criterion is not applicable and is provided here for information purposes only. There are no environmental resources of hazardous or critical concern that are designated, precisely mapped, or officially adopted in the vicinity of the project site, or that could be adversely affected by the project. Therefore, exception under State CEQA Guidelines Section 15300.2(a) does not apply to the project.

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Criterion 15300.2(b): Cumulative Impact
Yes No
Is there an exception to the exemption for the project due to significant cumulative impacts of successive projects of the same type and in the same place, over time? As demonstrated under Criterion Section 15332(a), General Plan and Zoning Consistency, the project would be consistent with the development density allowed under the General Plan and zoning for the project site. Successive projects of the same type (residential uses) and in the same place are unlikely to occur over time after the proposed residential uses are constructed.

Therefore, the exception under State CEQA Guidelines Section 15300.2(b) does not apply to the project.

Criterion 15300.2(c): Significant Effect
Yes No
Is there an exception to the exemption for the project because there is a reasonable possibility that the project will have a significant effect on the environment due to unusual circumstances?
There are no known unusual circumstances applicable to the project or its site that may result in a significant effect on the environment. Therefore, an exception to the exemption under State CEQA Guidelines Section 15300.2(c) does not apply to the project.

Criterion 15300.2(d): Scenic Highway
Yes No
Is there an exception to the exemption for the project because project may result in damage to scenic resources including but not limited to, trees, historic buildings, rock outcroppings or similar resources, within a highway officially designated as a state scenic highway?
The California Department of Transportation (Caltrans) Scenic Highway Program does not identify any state-designated scenic highways near the project site. The nearest officially designated State Scenic Highway is a portion of State Route 52, which begins where the freeway extends north and west past Mast Boulevard into Mission Trails Regional Park, approximately 3 miles west of the project site.

The project would not degrade views or damage scenic resources including trees, rock outcroppings, or historic buildings within a highway officially designated as a State Scenic Highway. Therefore, an exception to the exemption under State CEQA Guidelines Section 15300.2(d) does not apply to the project.

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Criterion 15300.2(e): Hazardous Waste Sites
Yes No
Is there an exception to the exemption for the project because the project is located on a site which is included on any list compiled pursuant to Section 65962.5 of the Government Code?
Hazardous materials sites compiled pursuant to Government Code Section 65962.5 are listed on the “Cortese List” (named after the Legislator who authored the legislation that enacted it), which is maintained by the California Department of Toxic Substances Control. The project site is not on any list of hazardous material sites compiled pursuant to Government Code Section 65962.5. Therefore, an exception to the exemption under Section 15300.2(e) does not apply to the project.

Criterion 15300.2(f): Historical Resources
Yes No
Is there an exception to the exemption for the project because the project may cause a substantial adverse change in the significance of a historical resource? A RECON archaeologist conducted a review of existing topographic maps and historic aerial photographs and determined that the project site has been fully disturbed since 1978. A 1947 topographic map represents the alignment of the current Mission Gorge Road adjacent to the project site to the north, as well as the current alignment of Aubrey Glen Drive adjacent to the project site to the west. The first available aerial photograph is from 1953, and it shows the current Mission Gorge Road alignment as a two-lane paved roadway and the current Aubrey Glen Drive alignment as a dirt road. A 1964 aerial photograph exhibits a building near the southwest corner of the project site that was replaced by a larger building by 1966, as seen in a 1966 aerial photograph. No changes were noted in the 1968 aerial photograph. However, a 1978 aerial photograph shows the project site to be fully developed by hardscape with at least two ancillary structures added, one near Mission Gorge Road and one along the southern project boundary.

The building near the southwest project corner is represented on a 1969 topographic map along with an additional structure represented to the east of the building along the southern project boundary on a 1978 topographic map. No changes were noted to the project site on subsequent topographic maps. The structure along the southern project boundary was updated or replaced in 1980 and 1981, with no additional changes exhibited on the 1982, 1983, and 1984 aerial photographs. However, an additional structure was added just south of the northern structure near Mission Gorge Road by 1985. In 1986, the southern structure was again expanded at its northeast end, but this expansion had been removed by 1991. No notable changes were exhibited on available aerial photographs between 1987 and 2000, but by 2002 another expansion was noted on the north side of the structure along the southern boundary. No notable changes to the project site were noted in a review of subsequent aerial photographs (Nationwide Environmental Title Research 2024). The ground surface of the project site has been fully disturbed by a combination of hardscape and buildings with associated structure development. The oldest remaining structure on the project site was constructed in 1978, so it does not have any potential significance as an historic resource. Consequently, the potential for historical period resources is considered low. Therefore, an exception to the exemption under State CEQA Guidelines Section 15300.2(f) does not apply to the project.

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VI. REFERENCES CITED
Bay Area Air Quality Management District (BAAQMD)
2022 California Environmental Quality Act Air Quality Guidelines. Adopted April 20, 2022.

Federal Highway Administration (FHWA)
2006 Roadway Construction Noise Model User’s Guide. FHWA-HEP-05-054, SOT-VNTSCFHWA-05-01. Final Report. January. 2008 Roadway Construction Noise Mode, V1.1. Washington, DC. 2011 Highway Traffic Noise: Analysis and Abatement Guidance. FHWA-HEP-10-025.

December.

Federal Transit Administration (FTA)
2006 Transit Noise and Vibration Impact Assessment. Washington, DC. May.

Office of Environmental Health Hazard Assessment (OEHHA) 2015 Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments (Guidance Manual), February.

Nationwide Environmental Title Research, LLC (NETR)
2024 Historic Aerials. Accessed on July 17, 2024. http://www.historicaerials.com.

San Diego Air Pollution Control District (SDAPCD)
2022 2022 Revision of the Regional Air Quality Strategy for San Diego County.

San Diego Association of Governments (SANDAG)
2002 (Not So) Brief Guide of Vehicular Traffic Generation Rates for the San Diego Region.

April.
2022 Transportation Forecast Information Center. Years 2025, 2035, and 2050 Series 14 traffic volumes. Accessed at https://tfic.sandag.org/map.html. October 10.

Santee, City of
2022 City of Santee Housing Element Rezone Program Implementation PEIR (SCH# 2021100263). June 17.

United States Department of the Interior
1983 Archeology and Historic Preservation; Secretary of the Interior's Standards and Guidelines.

APPENDICES
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KB Home
7734 Mission Gorge Road
386-701-02-00
This residential project will bring in new home ownership opportunities for both established and growing families, furthering “pride of ownership” throughout the neighborhood. The project is an infill redevelopment located at the Southeastern corner of Mission Gorge Road and Aubrey Glen Drive. The site is centrally located within a strong residential pocket with multi-family, apartments, and single-family homes at every direction. The site was previously the “Pure-Flo water company” commercial site. The proposed residential development will consist of 52 Units (22.6 du/ac). Specifically, 14, 3-story duplex units and 38, 3-story small lot detached units. The units will average approximately 1,400 square feet and will all feature 3 bedrooms, 2.5 bathrooms, plus a Den. Each unit will be EPA energy star certified, featuring fully electric appliances, solar panels, and garage EV chargers. Additionally, each unit is energy star certified along with EPA WaterSense WaterSmart appliance fixtures.
10/30/24
Troy Friedeck
S:\TRAFFIC\Development Review\Traffic Analyss Intake Form.docx Page 2 or 3

4. Trip Generation Information
4A: Total Project Site Trips After Fully Constructed
Fill out the table below to show the total trips for the project site for the completed project. The information in this table should include both existing facilities that will still be in use once the project is complete and new facilities that will be constructed. Use separate rows for each different type of land use.
# Land Use Description New or
Existing
Size (Number of
dwelling units or
square feet)
Trip Generation Rate Data Source
(Subject to City Staff approval)
Trip
Generation
Rate
Total
Daily Trips
1  SANDAG 2002 Trip Generation Rate
 Other:________________________________
2  SANDAG 2002 Trip Generation Rate
 Other:________________________________
3  SANDAG 2002 Trip Generation Rate
 Other:________________________________
4  SANDAG 2002 Trip Generation Rate
 Other:________________________________
5  SANDAG 2002 Trip Generation Rate
 Other:________________________________
Projected Total Average Daily Trips (ADT) for the site:______________________________ 4B: Total Existing Trips
Fill out the table below to show the total existing trips for the project site. Use separate rows for each different type of land use.
# Land Use Description
Size (Number of
dwelling units or
square feet)
Trip Generation Rate Data Source
(Subject to City Staff approval)
Trip Generation
Rate
Total
Daily Trips
1  SANDAG 2002 Trip Generation Rate
 Actual counts collected*
 Other:________________________________
2  SANDAG 2002 Trip Generation Rate
 Actual counts collected*
 Other:________________________________
3  SANDAG 2002 Trip Generation Rate
 Actual counts collected*
 Other:________________________________
4  SANDAG 2002 Trip Generation Rate
 Actual counts collected*
 Other:________________________________
* Note: If site counts are collected, they should be for a minimum of two full midweek days representing typical days when schools are in session.

Total Existing Average Daily Trips (ADT) for the site:______________________________ Single Family Housing New 52 DU ITE, 11th Edition 7.20 / DU 374 374 (see attached trip generation table prepared by LLG Engineers) S:\TRAFFIC\Development Review\Traffic Analyss Intake Form.docx Page 3 or 3

5. Vehicle Miles Traveled (VMT) Analysis
Projects that are projected to generate more than 500 total Average Daily Trips (ADT) may be required to submit a full VMT analysis. The total trips are all trips from the project site (new and/or existing) from the project site once fully constructed from Table 4A. If a VMT analysis is required, applicant shall refer to the City of Santee VMT Analysis guidelines.

Total number of project site trips (Section 4A): ______________________ Is the proposed project projected to have more than 500 ADT?  NO VMT analysis is not required for this project
 YES VMT analysis prepared may be required

6. Traffic Study Level of Service (LOS) Analysis
Projects that are projected to generate more than 1,000 new Average Daily Trips (ADT) may be required to submit a traffic study that evaluates traffic impact and performs a LOS analysis.

The new trips are determined by subtracting the existing number of trips (4B) from the total trips for the project site after buildout (4A). If a traffic study with LOS analysis is required, applicant shall refer to the San Diego ITE’s Guidelines for Transportation Impact Studies in the San Diego Region, May 2019.

Total new trips (Section 4A minus Section 4B): ______________________ Is the proposed project projected to have more than 1,000 ADT?  NO A traffic study is not required for this project
 YES A traffic study LOS analysis may be required
Is the proposed project projected to have more than 2,500 ADT?  NO A SANDAG model run is not required.
 YES A SANDAG model run may be required.

7. Technical Memorandum
If the total ADT is within 10% of any of the limits listed above, at the City’s discretion, a technical memorandum prepared by a registered traffic engineer may be required to verify calculations.

Is the proposed project projected Average Daily Trips over 450 VMT or 900 LOS?  NO A traffic memorandum is not required.
 YES A traffic memorandum prepared by a registered traffic engineer detailing if a VMT or Traffic Study LOS analysis may be required.
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SAN DIEGO, CA 92110
5620 FRIARS ROAD
619-291-0707
rickengineering.com
GRAPHIC SCALE 1" = 20'
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08-MAY-2024 13:17
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6' MAX. HEIGHT WALL
10' SETBACK
10'SETBACK
347.0
63-214129, REC. 12/03/68
EASEMENT PER DOC. NO.

EXIST. 3' PRIVATE WATER

3.0'

10.0'
EXIST.6"SEWER (PUBLIC)
EXIST.8"SEWER (PUBLIC)
25' SETBACK
26'
26'
32'
2 6'

24.0'
30'
24'
2 6'
347.3
349.4
349.5
2 6'
3 2'
26'
26'
26'
346.3
10' SETBACK
10' SETBACK
3 2'
32'
EXIST.6"WATER (PUBLIC)
REC. 5/31/68
PER DOC. NO. 91288,

EASEMENT TO PDMWD
EXIST. 10' WATER

SANTEE, CA

MISSION GORGE

CONCEPTUAL SITE PLAN
DEVELOPMENT NOTES:
05/08/2024
EX.

TOTAL PROVIDED: 129 SPACES
OFFSITE (STREET) - 12 SPACES
ONSITE - 13 SPACES
52 (2-CAR GARAGES) - 104 SPACES
PARKING PROVIDED:

TOTAL REQUIRED: 117 SPACES
52 x 0.25(GUEST) - 13 SPACES
52 (2-CAR GARAGES) - 104 SPACES
PARKING REQUIRED:

DENSITY: 22 DU/AC.

PROPOSED UNITS: 52
* - AREA REMAINING WITHIN SETBACK LIMITS
*NET AREA: 2.3 AC.

GROSS AREA: 3.34 AC.
3-24-3939 Aubrey Glen
Project Trip Generation
N:\3939 - Aubrey Glen\Trip Gen\Aubrey Glen Trip Generation Table.docx` In Out Total In Out Total
Single-Family Attached Housing 52 DU 7.2 /DU 374 0.48 /DU 31% : 69% 8 17 25 0.57 /DU 57% : 43% 17 13 30 Total 374 8 17 25 17 13 30
Footnotes:
a. ADT = Average Daily Traffic
b. Rates are based on ITE Trip Generation Manual, 11th Edition - Land Use 215 (Single-Family Attached Housing) General Notes:

1. DU = Dwelling Units
Volume
Rate In:Out
Split
Volume
Project Trip Generation
Land Use Description Size
Daily Trip Ends
(ADTs) a AM Peak Hour PM Peak Hour
Rate b Volume Rate In:Out Split
An Employee-Owned Company
3111 Camino del Rio North, Suite 600, San Diego, CA 92108-5726 | 619.308.9333 | reconenvironmental.com SAN DIEGO | OAKLAND | TUCSON
January 20, 2025
Mr. Troy Friedeck
KB Home Coastal, Inc.
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
Reference: Noise Analysis for the Aubrey Glen Project (RECON Number 10174-1) Dear Mr. Friedeck:

The purpose of this report is to assess potential noise impacts from construction and operation of the Aubrey Glen Project (project). Impacts are assessed in accordance with standards established in the City of Santee’s (City) General Plan Noise Element and the City’s Municipal Code.

1.0 Introduction

1.1 Project Description
The project site is located at 7737 Mission Gorge Road (Assessor’s Parcel Number 386-300-31-00) in the city of Santee, California. The project site is located east of Aubrey Glen Drive and south of Mission Gorge Road. The

2.63-acre project site is currently developed with 11,700 square feet of vacant retail buildings surrounded by concrete and asphalt parking lots and minimal landscape planters. The project is bordered by Mission Gorge Road to the north, commercial and residential uses to the east, and high-density residential uses to the south and west. Figure 1 shows the regional location of the project. Figure 2 shows an aerial photograph of the project site and vicinity.

The project would construct 52 residential dwelling units. Fourteen units would consist of attached residential, configured within seven, three-story duplex buildings, and each of the remaining 38 units would consist of three-story detached residential buildings. The residential units would average approximately 1,400 square feet in size, and the project would be consistent with the existing zoning designation of High-Density Residential R-22 (22 to 30 dwelling units per acre). All 52 residential units would be configured with 3 bedrooms and 2.5 bathrooms, and 25 of these residential units would also be configured with a den. All 52 residential units would have private open space by way of patio/entry space and balcony/deck. Vehicular access would be provided via a driveway connecting to Aubrey Glen Drive. All 52 residential units would include a private two-car garage, providing for a total of 104 residential parking spaces. The project would also provide 15 on-site guest parking spaces. Overall, the project would provide a total of 119 parking spaces, which would exceed the City’s parking requirement of 2.25 parking spaces per unit. Furthermore, the project would provide 12 off-site parking spaces along Aubrey Glen Drive that would be regulated by City right-of-way with signage. These 12 off-site parking spaces would not be exclusive to the project, and therefore are not included in the parking count. The project would also provide approximately 5,000 square feet of common open space with amenities that would be managed by a private homeowners association. Figure 3 shows the proposed site plan.

USMC AIR

STATION

S A N D I E G O

C O U N T Y

USMC AIR

STATION

S A N D I E G O

C O U N T Y

ANGELES

ORANGE RIVERSIDE

SAN BERNARDINO

SAN DIEGO
MEXICO
kj Project Location
FIGURE 2
Project Location on Aerial Photograph

WEST HILLS PKY

MISSION GORGE RD

CYPRESS DR

VIA MONTISI

ARUBA LN

BU S HY HILL DR

TRINIDAD CT

CORAL RIDGE RD

VIA SOVANA

WREN ST

AUBREY GLEN

DOVE ST LA
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HIGHRIDG
E
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OLIVEH ILL R
D

S UNRIDGE
DR

WOODPECKER WAY

HISER LN

FERNRIDGE RD

STELLA CT

ORGANDY LN

CRESCENT RIDGE RD

LINEN DR

ARLY CT

WISTFUL VISTA

PINERIDG E
RD

SIMEON DR

ROLLING OAKS RD

STARPINE DR

RIDGECREST RD

BRITT PL
UV52

WEST HILLS PKY

MISSION GORGE RD

CYPRESS DR

VIA MONTISI

ARUBA LN

BU S HY HILL DR

TRINIDAD CT

CORAL RIDGE RD

VIA SOVANA

WREN ST

AUBREY GLEN

DOVE ST LA
U
REL H
EIG
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DR
BUSHY
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DR

FATHER JUNIPERO SERRA TRL
C
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AY

ROSEMOND LN

CLARE LN

DOVE ST

ROBINSON LN

HIGHRIDG
E
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D

RANCHO FANITA DR

OLIVEH ILL R
D

S UNRIDGE
DR

WOODPECKER WAY

HISER LN

FERNRIDGE RD

STELLA CT

ORGANDY LN

CRESCENT RIDGE RD

LINEN DR

ARLY CT

WISTFUL VISTA

PINERIDG E
RD

SIMEON DR

ROLLING OAKS RD

STARPINE DR

RIDGECREST RD

BRITT PL
UV52
Image Source: NearMap (flown May 2024)
0 Feet 500 [
Project Boundary
M:\JOBS6\10174\common_gis\MXD\10174.1\fig2_nos.mxd 7/11/2024 fmm M:\JOBS6\10174\nos\graphics\Fig3.afdesign 11/13/24 bma
Map Source: Summa Architecture
FIGURE 3
Site Plan
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The following project conditions related to noise would be required. These measures would be incorporated as Conditions of Approval for the entitlement of the site.

Standard Project Condition No. 4 – Noise:

4. The following note shall be incorporated into the project construction plan: “Control of Construction Hours.

Construction activities occurring as part of the project shall be subject to the limitations and requirements of Section 5.04.090 of the City Municipal Code which states that construction activities may occur between 7:00 a.m. and 7:00 p.m. Mondays through Saturdays. No construction activities shall be permitted outside of these hours or on Sundays and holidays.”

1.2 Fundamentals of Noise
Sound levels are described in units called the decibel (dB). Decibels are measured on a logarithmic scale that quantifies sound intensity in a manner similar to the Richter scale used for earthquake magnitudes. Thus, a doubling of the energy of a noise source, such as doubling of traffic volume, would increase the noise level by 3 dB; a halving of the energy would result in a 3 dB decrease.

Additionally, in technical terms, sound levels are described as either a “sound power level” or a “sound pressure level,” which while commonly confused are two distinct characteristics of sound. Both share the same unit of measure, the dB. However, sound power, expressed as Lpw, is the energy converted into sound by the source. The Lpw is used to Mr. Troy Friedeck

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estimate how far a noise will travel and to predict the sound levels at various distances from the source. As sound energy travels through the air, it creates a sound wave that exerts pressure on receivers such as an eardrum or microphone and is the sound pressure level. Noise measurement instruments only measure sound pressure, and noise level limits used in standards are generally sound pressure levels.

The human ear is not equally sensitive to all frequencies within the sound spectrum. To accommodate this phenomenon, the A-scale, which approximates the frequency response of the average young ear when listening to most ordinary everyday sounds, was devised. When people make relative judgments of the loudness or annoyance of a sound, their judgments correlate well with the A-scale sound levels of those sounds. Therefore, the “Aweighted” noise scale is used for measurements and standards involving the human perception of noise. Noise levels using A-weighted measurements are designated with the notation dB(A). The impact of noise is not a function of loudness alone. The time of day when noise occurs and the duration of the noise are also important. In addition, most noise that lasts for more than a few seconds is variable in its intensity. Consequently, a variety of noise descriptors has been developed. The noise descriptors used for this study are the one-hour equivalent noise level (Leq), the community noise equivalent level (CNEL), and the day night equivalent level (Ldn). The CNEL is a 24-hour equivalent sound level.

The CNEL calculation applies an additional 5 dB(A) penalty to noise occurring during evening hours, between 7:00 p.m. and 10:00 p.m., and an additional 10 dB(A) penalty is added to noise occurring during the night, between 10:00 p.m. and 7:00 a.m. These increases for certain times are intended to account for the added sensitivity of humans to noise during the evening and night. Similar to the CNEL, the Ldn is a 24-hour equivalent level that applies an additional 10 dB(A) penalty to noise occurring during the night.

Sound from a small, localized source (approximating a “point” source) radiates uniformly outward as it travels away from the source in a spherical pattern, known as geometric spreading. The sound level decreases or drops off at a rate of 6 dB(A) for each doubling of the distance.

Traffic noise is not a single, stationary point source of sound. The movement of vehicles makes the source of the sound appear to emanate from a line (line source) rather than a point when viewed over some time interval. The drop-off rate for a line source is 3 dB(A) for each doubling of distance.

The propagation of noise is also affected by the intervening ground, known as ground absorption. A hard site (such as parking lots or smooth bodies of water) receives no additional ground attenuation, and the changes in noise levels with distance (drop-off rate) are simply the geometric spreading of the source. A soft site (such as soft dirt, grass, or scattered bushes and trees) receives an additional ground attenuation value of 1.5 dB(A) per doubling of distance.

Thus, a point source over a soft site would attenuate at 7.5 dB(A) per doubling of distance.

Human perception of noise has no simple correlation with acoustical energy. A change in noise levels is generally perceived as follows: 3 dB(A) barely perceptible, 5 dB(A) readily perceptible, and 10 dB(A) perceived as a doubling or halving of noise (California Department of Transportation 2013).

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2.0 Applicable Standards

2.1 General Plan
The City’s General Plan Noise Element includes various goals, objectives, and policies related to noise standards and protections against excessive noise exposure, including the following:

Objective 1.0. Control noise from sources adjacent to residential, institutional, and other noise-sensitive receptors. • Policy 1.1: The City shall support a coordinated program to protect and improve the acoustical environment of the City including development review for new public and private development and code compliance for existing development.
• Policy 1.2: The City shall utilize noise studies and noise contour maps when evaluating development proposals during the discretionary review process.
• Policy 1.4: The City shall promote alternative sound attenuation measures rather than traditional wall barrier wherever feasible; these may include glass or polycarbonate walls, berms, landscaping, and the siting of noise-sensitive uses on a parcel away from the roadway or other noise source. • Policy 1.5: The City shall review future projects with particular scrutiny regarding the reduction of unnecessary noise near noise-sensitive areas such as hospitals, schools, parks, etc.

Objective 2.0. Ensure that future developments will be constructed to minimize interior and exterior noise levels. • Policy 2.1: The City shall adhere to planning guidelines and building codes which include noise control for the exterior and interior living space of all new residential developments within noise impacted areas. • Policy 2.2: The City should require new development to mitigate noise impacts to existing uses resulting from new development when: (1) such development adds traffic to existing City streets that necessitates the widening of the street; and (2) the additional traffic generated by new development causes the noise standard or significance thresholds to be exceeded.
• Policy 2.3: The City should not require new development to mitigate noise impacts to existing uses when new development only adds traffic already anticipated by the City’s General Plan to an existing street but does not necessitate widening of that street.

The Noise Element also provides guidelines for determining acceptable and unacceptable community noise exposure limits for various land use categories (Table 1). Normally acceptable noise levels are defined as satisfactory, based on the assumption that any buildings involved are of normal conventional construction, without any special noise insulation requirements. Conditionally acceptable noise levels indicate that new construction or development should be undertaken only after a detailed analysis of the noise reduction requirements is made and needed noise insulation features have been included in the design. Conventional construction with closed windows and fresh air supply systems or air conditioning will normally suffice. The City’s General Plan states that these compatibility guidelines are not prohibitive but should be used as a guide and a resource (City of Santee 2003). As shown in Table 1 below, residential land uses are normally acceptable with noise levels up to 65 CNEL, conditionally acceptable with noise levels from 65 to 70 CNEL, normally unacceptable with noise levels from 70 to 75 CNEL, and clearly unacceptable with noise levels above 75 CNEL.

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Table 1
Noise/Land Use Compatibility Guide
Community Noise Exposure (CNEL)
55 60 65 70 75 80
Residential – Low Density Single Family,
Duplex, Mobile Homes
Residential – Multiple Family
Transient Lodging – Motels, Hotels
Schools, Libraries, Churches, Hospitals,
Nursing Homes1
Auditoriums, Concert Halls, Amphitheaters
Sports Arena, Outdoor Spectator Sports
Playgrounds, Neighborhood Parks
Golf Courses, Riding Stables, Water
Recreation, Cemeteries
Office Buildings, Business Commercial and
Professional
Industrial, Manufacturing, Utilities,
Agriculture
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Table 1
Noise/Land Use Compatibility Guide 1
Applies to noise sensitive areas which serve a significant function for the use which could be adversely affected by noise; such as, outside areas used primarily for instruction, meditation areas, rest and relaxation areas, and other areas where general peace and quiet are important.

Normally Acceptable:

Specified land use is satisfactory, based upon the assumption that any buildings involved are of normal conventional construction, without any special noise insulation requirements.

Conditionally Acceptable:

New construction or development should be undertaken only after a detailed analysis of the noise reduction requirement is made and needed noise insulation features included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning will normally suffice.

Normally Unacceptable:

New construction or development should generally be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features included in the design.

Clearly Unacceptable:

New construction or development should generally not be undertaken.

The Noise Element further states that when new development may result in the exposure of existing or future noise-sensitive uses to noise levels in excess of 65 dB(A) Ldn, an acoustical study will be required. If the acoustical study shows that the noise levels at any noise-sensitive area will exceed 65 dB(A) Ldn, the development should not be approved unless the following findings are made:

1. Modifications to the development have been, or will be made, which will reduce the exterior noise levels in noise-sensitive areas to 65 dB(A) Ldn or less, or

2. If, with current noise abatement technology, it is not feasible to reduce the exterior noise levels to 65 dB(A) Ldn or less, then modifications to the development have been, or will be made, which reduce the exterior noise level to the maximum extent feasible and the interior noise level to 45 dB(A) Ldn or less.

Particular attention shall be given to noise-sensitive spaces such as bedrooms.

3. For rooms in noise-sensitive areas which are occupied only for a part of the day (schools, libraries, or similar), the interior 1-hour average sound level during occupation, due to noise outside, should not exceed 45 dB(A) Leq.

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Further, noise impacts shall be considered significant if any of the following occur as a result of the project:

1. If, as a direct result of the project, noise levels for any existing or planned development will exceed the noise levels considered compatible for that use as identified in Table 1.

2. If, as a direct result of the proposed development, noise levels which already exceed the levels considered compatible for that use are increased by 3 dB or more.

Section 8.0, Implementation of the Noise Element lists the following measures that may be incorporated into a proposed project as mitigation measures. The following measures are not always required, and mitigation is not limited to this list:

1. The use of site design techniques, such as the provision of buffers to increase distances between the noise source and receiver, siting of buildings and parking areas, and the careful siting of noise-sensitive outdoor features to minimize noise impacts.

2. Provision of berms, landscaping, and other sound barriers, without the exclusive use of walls (e.g., a combination of a small wall and a berm in concert with the overall streetscape in the area could be appropriate).

3. Insulation of buildings against noise, including thicker-than-standard glazing and mechanical ventilation.

4. Improvement of traffic circulation to “smooth” flow by such measures as interconnecting traffic signals.

5. Consideration of the use of innovative construction technologies and materials in constructing or reconstructing streets.

6. Setting of time limits on certain noisy activities.

7. Purchasing of demonstrably quiet equipment for City use.

2.2 Municipal Code
Title 5 - Health and Safety
Chapter 5.04 Noise Abatement and Control Ordinance
On-site generated noise is regulated by the City’s Municipal Code, Title 5 Health and Safety, Chapter 5.04 Noise Abatement and Control. The sections applicable to the project are as follows:

Section 5.04.040 General Noise Regulations
A. General Prohibitions. It is unlawful for any person to make, continue, or cause to be made or continued, within the limits of the City, any disturbing, excessive or offensive noise which causes discomfort or annoyance to reasonable persons of normal sensitivity residing in the area. The characteristics and conditions which should be considered in determining whether a violation of the provisions of this section exists, include, but are not limited to, the following:

1. The level of the noise;

2. Whether the nature of the noise is usual or unusual; Mr. Troy Friedeck

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3. Whether the origin of the noise is natural or unnatural;

4. The level of the background noise;

5. The proximity of the noise to sleeping facilities;

6. The nature and zoning of the area within which the noise emanates;

7. The density of the inhabitation of the area within which the noise emanates;

8. The time of day or night the noise occurs;

9. The duration of the noise;

10. Whether the noise is recurrent, intermittent, or constant; and

11. Whether the noise is produced by a commercial or noncommercial activity.

B. Disturbing, Excessive or Offensive Noises. The following acts, among others, are declared to be disturbing, excessive and offensive noises in violation of this section:

1. Heating and Air Conditioning Equipment and Generators. a. It is unlawful for any person to operate or allow the operation of any generator, air conditioning, refrigeration or heating equipment in such manner as to create a noise disturbance on the premises of any other occupied property, or if a condominium, apartment house, duplex, or attached business, within any adjoining unit.
b. All generators, heating, air conditioning, or refrigeration equipment are subject to the setback and screening requirements in this code.

Section 5.04.070 Motorized Equipment
It is unlawful to operate any lawn mower, backpack blower, lawn edger, leaf blower, riding tractor, or any other machinery, equipment, or other device, or any hand tool which creates a loud, raucous or impulsive sound, within or adjacent to any residential zone between the hours of 10:00 p.m. and 7:00 a.m. of the following day.

Section 5.04.130 Loading and Unloading Operations
A. It is unlawful for any person to engage in loading, unloading, opening, idling of trucks, closing or other handling of boxes, crates, containers, building materials, garbage cans, dumpsters or similar objects between the hours of 10:00 p.m. and 7:00 a.m. in such a manner as to cause a noise disturbance within or adjacent to a residential district.

Section 5.04.160 Limitations on sources of noise not otherwise addressed:

A. Between 10:00 p.m. and 7:00 a.m., it is unlawful for any person to generate any noise on the public way that is louder than average conversational level at a distance of 50 feet or more, vertically or horizontally, from the source.

B. Between 10:00 p.m. and 7:00 a.m., no person is permitted to generate any noise on any private open space that is louder than average conversational level at a distance of 50 feet or more, measured from the property line of the property from which the noise is being generated.

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The Noise Abatement and Control Ordinance establishes the City’s noise regulation, generally prohibits nuisance noise and states that it is unlawful for any person to make, continue, or cause to be made or continued within the City limits any disturbing, excessive, or offensive noise that causes discomfort or annoyance to reasonable persons of normal sensitivity residing in the area [Municipal Code Section 5.04.040(A)].

Municipal Code Section 5.04.090, which specifically pertains to construction equipment, makes operation of any construction equipment outside the hours of 7:00 a.m. through 7:00 p.m., Monday through Saturday, except holidays, unlawful unless the operation is expressly approved by the Director of Development Services. Construction equipment with a manufacturer’s noise rating of 85 dBA Lmax or greater may only operate at a specific location for 10 consecutive workdays. If work involving such equipment would involve more than 10 consecutive workdays, a notice must be provided to all property owners and residents within 300 feet of the site no later than 10 days before the start of construction. The notice must be approved by the City and describe the proposed project and the expected duration of work and provide a point of contact to resolve noise complaints.

Title 13 - Zoning
Chapter 13.30 General Development and Performance Standards The intent of this section is to protect properties in all districts and the health and safety of persons from environmental nuisances and hazards and to provide a pleasing environment in keeping with the nature of the district character. Section 13.30.030 applies to operation of land uses and states that no operation or activity is permitted which will create vibration noticeable without instruments at the perimeter of the subject property.

3.0 Existing Conditions
Existing noise contour mapping was developed as part of the City of Santee Housing Element Rezone Program Implementation PEIR (Rezone PEIR; City of Santee 2022). The project site was identified as a redevelopment site in the Rezone PEIR. Noise levels at the project site are dominated by vehicle traffic on Mission Gorge Road and State Route 52 (SR-52). Existing year 2020 vehicle traffic noise contours are shown in Figure 4. Noise level contours do not take into account topography or shielding provided by intervening structures and are therefore conservative. As shown in Figure 4, existing noise levels exceed 60 CNEL across the entire project site and exceed 65 CNEL across the northern 180 feet of the project site.

4.0 Methodology
Noise level predictions and contour mapping were developed using noise modeling software, SoundPlan Essential, version 4.1 (Navcon Engineering 2018). SoundPLAN calculates noise propagation based on the International Organization for Standardization method (ISO 9613-2 – Acoustics, Attenuation of Sound during Propagation Outdoors). The model calculates noise levels at selected receiver locations using input parameter estimates such as total noise generated by each noise source; distances between sources, barriers, and receivers; and shielding provided by intervening terrain, barriers, and structures. The model outputs can be developed as noise level contour maps or noise levels at specific receivers. In all cases, receivers were modeled at 5 feet above ground elevation, which represents the average height of the human ear.

FIGURE 4
Existing Year 2020 Vehicle Traffic Noise Contours

WEST HILLS PKY

MISSION GORGE RD

CYPRESS DR

VIA MONTISI

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TRINIDAD CT

CORAL RIDGE RD

VIA SOVANA

WREN ST

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DR

WOODPECKER WAY

ORGANDY LN

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STELLA CT

CRESCENT RIDGE RD

ARLY CT

WISTFUL VISTA

PINERIDG E
RD

SIMEON DR

ROLLING OAKS RD

STARPINE DR

RIDGECREST RD

BRITT PL
UV52

WEST HILLS PKY

MISSION GORGE RD

CYPRESS DR

VIA MONTISI

ARUBA LN

BU S HY HILL DR

TRINIDAD CT

CORAL RIDGE RD

VIA SOVANA

WREN ST

AUBREY GLEN

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WOODPECKER WAY

ORGANDY LN

HISER LN

FERNRIDGE RD

STELLA CT

CRESCENT RIDGE RD

ARLY CT

WISTFUL VISTA

PINERIDG E
RD

SIMEON DR

ROLLING OAKS RD

STARPINE DR

RIDGECREST RD

BRITT PL
UV52
Image Source: NearMap (flown May 2024)
Project Boundary 2020 Vehicle Traffic Noise 0 Feet 500 [ 60 CNEL
65 CNEL
70 CNEL
75 CNEL
M:\JOBS6\10174\common_gis\MXD\10174.1\fig4_nos.mxd 7/11/2024 fmm Mr. Troy Friedeck

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4.1 Construction Noise Analysis
Project construction noise would be generated by diesel engine-driven construction equipment used for site preparation and grading, building construction, loading, unloading, and placing materials and paving. Diesel engine-driven trucks also would bring construction materials to the site.

Construction equipment with a diesel engine typically generates maximum noise levels from 70 to 95 dB(A) Leq at a distance of 50 feet (Federal Highway Administration [FHWA] 2006 and 2008; Federal Transit Authority 2006). During construction, equipment moves to different locations and goes through varying load cycles, and there are breaks for the operators and for nonequipment tasks, such as measurement. Table 2 summarizes typical construction equipment noise levels and duty cycles.

During excavation, grading, and paving operations, equipment moves to different locations and goes through varying load cycles, and there are breaks for the operators and for non-equipment tasks, such as measurement.

Although maximum noise levels may be 70 to 95 dB(A) at a distance of 50 feet during most construction activities, hourly average noise levels from the grading phase of construction would be 85 dB(A) Leq at 50 feet from the center of construction activity when assessing the loudest pieces of equipment–dozer, excavator, and loader–working simultaneously. Noise levels were modeled as an area source over the footprint of the project. Note that the project site has been previously disturbed and developed, and no blasting would be required.

Table 2
Typical Construction Equipment Noise Levels
Equipment
Noise Level at 50 Feet
[dB(A) Leq]
Typical Duty
Cycle
Auger Drill Rig 85 20%
Backhoe 80 40%
Blasting 94 1%
Chain Saw 85 20%
Clam Shovel 93 20%
Compactor (ground) 80 20%
Compressor (air) 80 40%
Concrete Mixer Truck 85 40%
Concrete Pump 82 20%
Concrete Saw 90 20%
Crane (mobile or stationary) 85 20%
Dozer 85 40%
Dump Truck 84 40%
Excavator 85 40%
Front End Loader 80 40%
Generator (25 kilovolt amps or less) 70 50%
Generator (more than 25 kilovolt amps) 82 50%
Grader 85 40%
Hydra Break Ram 90 10%
Impact Pile Driver (diesel or drop) 95 20%
In situ Soil Sampling Rig 84 20%
Jackhammer 85 20%
Mounted Impact Hammer (hoe ram) 90 20%
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Table 2
Typical Construction Equipment Noise Levels
Equipment
Noise Level at 50 Feet
[dB(A) Leq]
Typical Duty
Cycle
Paver 85 50%
Pneumatic Tools 85 50%
Pumps 77 50%
Rock Drill 85 20%
Roller 74 40%
Scraper 85 40%
Tractor 84 40%
Vacuum Excavator (vac-truck) 85 40%
Vibratory Concrete Mixer 80 20%
Vibratory Pile Driver 95 20%
dB(A) Leq = A-weighted decibels average noise level
SOURCE: Federal Highway Administration 2006 and 2008; Federal Transit Authority 2006.

4.2 Traffic Noise Analysis
The SoundPLAN program uses the FHWA Traffic Noise Model algorithms and reference levels to calculate traffic noise levels at selected receiver locations. The model uses various input parameters, such as projected hourly average traffic rates; vehicle mix, distribution, and speed; roadway lengths and gradients; distances between sources, barriers, and receivers; and shielding provided by intervening terrain, barriers, and structures. Receivers, roadways, and barriers were input into the model using three-dimensional coordinates.

The main source of traffic noise at the project site is vehicle traffic on Mission Gorge Road and SR-52. Existing and future (year 2050) traffic volumes, speeds, and truck percentages were obtained from the Transportation Impact Study prepared for the Rezone PEIR (CR Associates 2021). The existing vehicle traffic volumes were used to determine if the project would result in a significant increase in ambient noise levels. The future (year 2050) vehicle traffic volumes were used to model future noise levels and determine compatibility with the City’s noise standards. A vehicle classification mix of 95.4 percent automobiles, 2.0 percent medium trucks, 0.2 percent heavy trucks, 1.0 percent buses, and 1.0 percent motorcycles was modeled. This classification mix is based on Caltrans’ SR-52 truck counts near the project site and is adjusted to account for buses and motorcycles (Caltrans 2021) Table 3 summarizes the modeled future vehicle traffic parameters.

Table 3
Vehicle Traffic Parameters
Roadway Segment
Existing (Year 2020)
ADT
Future (Year 2050)
ADT
Speed
(mph)
SR-52 116,516 134,367 65
Mission Gorge Road 12,877 16,606 50
ADT = Average Daily Trips; mph = miles per hour
SOURCE: CR Associates 2021
Mr. Troy Friedeck

Page 16 ends

January 20, 2025

4.3 On-Site Noise Analysis
Operational noise sources on the project site are anticipated to be typical of any residential neighborhood, such as vehicles arriving and leaving, children at play, and landscape maintenance machinery. None of these noise sources associated with residential uses are anticipated to violate the City’s Municipal Code or result in a substantial permanent increase in existing noise levels. The project would include heating, ventilation, and air conditioning (HVAC) units. Noise levels due to HVAC units were modeled to determine if they have the potential to produce noise in excess of City limits. In accordance with the Noise Element of the General Plan, the noise level threshold is 65 dB(A) Leq at the property line.

The HVAC equipment would be located on the ground next to each of the residential units. It is not known at this time which manufacturer, brand, or model of unit or units would be selected for use in the project. For the purposes of this analysis, to determine what general noise levels the HVAC units would generate, it was assumed that the HVAC units would be similar to a Carrier unit with a sound power level of 75 dB(A). Noise specifications are presented in Attachment 1. All units were modeled at full capacity during the daytime and nighttime hours.

5.0 Noise Impacts

5.1 Construction Noise Analysis
Noise level limits for construction activities are established in Section 5.04.090 of the City’s Municipal Code. These limits state that a notice must be provided to all owners and occupants within 300 feet of the project site if the construction equipment has a manufacturer’s noise rating of 85 dB and operates at a specific location for 10 consecutive workdays.

In addition, Section 5.04.090 of the City’s Municipal Code states that no construction equipment is permitted before 7:00 a.m. or after 7:00 p.m. on Mondays through Saturdays and all times on Sundays and holidays.

Surrounding land uses include Mission Gorge Road to the north, commercial and residential uses to the east, and high-density residential uses to the south and west. Noise associated with the construction of the project was modeled at a series of 15 receivers located at the adjacent properties. The results are summarized in Table 4.

Construction noise contours are shown in Figure 5. SoundPLAN data is contained in Attachment 2.

FIGURE 5
Construction Noise Contours
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1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 WEST HILLS PKY

MIRABELLE LN

MISSION GORGE RD

SAGE CT

BELLAMONT PASS

BASSETT LN

LAUREL CT

CYPRESS DR

WREN ST

AUBREY GLEN

DOVE ST
LAUREL
H

E IGHTS
D
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ROSEMOND LN

VIA M ONTISI

CLARE LN

DOVE ST

JASMINE CT

HISER LN

ROLLING OAKS
RD

STARPINE DR
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1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 WEST HILLS PKY

MIRABELLE LN

MISSION GORGE RD

SAGE CT

BELLAMONT PASS

BASSETT LN

LAUREL CT

CYPRESS DR

WREN ST

AUBREY GLEN

DOVE ST
LAUREL
H

E IGHTS
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ROSEMOND LN

VIA M ONTISI

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DOVE ST

JASMINE CT

HISER LN

ROLLING OAKS
RD

Page 18 ends

January 20, 2025
Table 4
Construction Noise Levels at Off-Site Receivers
[dB(A) Leq]
Receiver Land Use Designation Construction Noise Level
1 R14 (Medium-High Density Residential) 70
2 R14 (Medium-High Density Residential) 72
3 R14 (Medium-High Density Residential) 72
4 R14 (Medium-High Density Residential) 71
5 R7 (Medium Density Residential) 70
6 R7 (Medium Density Residential) 73
7 R7 (Medium Density Residential) 73
8 R7 (Medium Density Residential) 73
9 GC (General Commercial) 73
10 GC (General Commercial) 74
11 GC (General Commercial) 74
12 GC (General Commercial) 73
13 R7 (Medium Density Residential) 63
14 R7 (Medium Density Residential) 66
15 R7 (Medium Density Residential) 66
dB(A) Leq = A-weighted decibels equivalent noise level.

As shown in Table 4, construction noise levels are anticipated to range from 63 to 74 dB(A) Leq at the adjacent properties. Although the existing adjacent uses would be exposed to construction noise levels that could be heard above ambient conditions, the exposure would be temporary. The project would not require construction equipment that has a manufacturer’s noise rating of 85 dB or higher. In accordance with Section 5.04.090 of the City’s Municipal Code, construction activities would not occur before 7:00 a.m. or after 7:00 p.m. on Mondays through Saturdays and would not occur any time on Sundays and holidays. Additionally, the project would be subject to Standard Project Condition No. 4 – Noise, items 1 through 4 (refer to Section 1.1). Compliance with this condition would reduce construction noise impacts to less than significant. As construction activities associated with the project would comply with requirements of the Noise Abatement and Control Ordinance, impacts associated temporary increases in noise levels during construction would be less than significant.

5.2 Traffic Noise Analysis

5.2.1 On-Site Noise Compatibility
Noise and land use compatibility is regulated by the Noise Element of the City’s General Plan. As shown in Table 1, residential land uses are normally acceptable with noise levels up to 65 CNEL, conditionally acceptable with noise levels from 65 to 70 CNEL, normally unacceptable with noise levels from 70 to 75 CNEL, and clearly unacceptable with noise levels above 75 CNEL.

Vehicle traffic noise level contours across the project site were calculated using SoundPLAN. These contours take into account the project area topography and the proposed buildings. Noise levels were also modeled at a series of firstthrough fifth floor receivers located around the proposed buildings. Vehicle traffic noise contours and receiver locations are shown in Figure 6. The results are summarized in Table 5. SoundPLAN data are provided in Attachment 3.

FIGURE 6
Vehicle Traffic Noise Contours
!( !(
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MIRABELLE LN

DOVE ST

WEST HILLS PKY

LAURELHEIGHTS
DR

WREN ST

MISSION GORGE RD

BELLAMONT PASS

BASSETT LN

LAUREL CT
A
U
B
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GLE
N

MIRABELLE CT

ROSEMOND LN

CLARE LN

SAGE CT

HISER LN

STARPINE DR
1 2
3 4
5 6
7 8
9 10 11 12 13
14 15 16
17 18
19 20
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LAUREL CT
A
U
B
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GLE
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MIRABELLE CT

ROSEMOND LN

CLARE LN

SAGE CT

HISER LN

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January 20, 2025
Table 5
Vehicle Traffic Noise Levels
(CNEL)
Receiver 1st Floor 2nd Floor 3rd Floor
1 67 69 69
2 66 68 69
3 61 63 65
4 60 63 64
5 52 56 59
6 55 58 61
7 52 56 59
8 50 54 57
9 46 50 53
10 51 55 58
11 58 61 62
12 59 61 63
13 59 62 63
14 53 57 59
15 47 51 53
16 44 48 51
17 43 46 48
18 44 47 50
19 39 44 47
20 47 51 54
CNEL = community noise equivalent level
As shown in Figure 6 and Table 5, exterior noise levels would be 65 CNEL or less at all receivers except at Receivers 1 and 2 on the northern side of the northernmost buildings closest to Mission Gorge Road. However, for Receivers 1 and 2, there are no proposed exterior use areas on the northern sides of those buildings. Patios would be located on the southern side of those buildings shielded from Mission Gorge Road. Exterior noise levels would not exceed the “normally acceptable” noise level limit of 65 CNEL at any proposed exterior use areas. Therefore, the project would not expose receivers to exterior noise levels in excess of standards established in the City’s General Plan, and impacts would be less than significant.

The interior noise level standard for residential uses is 45 CNEL. As shown in Table 5, with the exception of Receivers 1 and 2, exterior noise levels would range from 39 to 65 CNEL. Standard light-frame construction would reduce exterior to interior noise levels by at least 20 dB. This analysis conservatively assumes that standard construction techniques would achieve 20 dB exterior to interior noise reduction. Using this assumption, interior noise levels would be reduced to 45 CNEL or less.

Page 21 ends

January 20, 2025
building component attenuates noise. The STC rating general reflects the decibel reduction that a building component can achieve. Noise levels on the northern side of these units would be up to 69 CNEL. Therefore, because a noise reduction of up to 24 dB(A) is required to achieve interior noise levels of 45 CNEL or less, building components with an STC rating of up to 24 would be required. Standard walls and roofs typically have STC ratings greater than 40, and therefore would achieve the required noise reduction. In order to achieve an interior noise level of 45 CNEL or less in the two units closest to Mission Gorge Road, windows with an STC of 24 or greater would be required. The inclusion of windows with an STC of 24 in the two units closest to Mission Gorge Road shall be a project condition of approval (see Standard Condition No. 4, item 5). Therefore, the project would not expose receivers to interior noise levels in excess of standards established in the General Plan, and impacts would be less than significant.

5.2.2 Off-Site Vehicle Traffic Noise
The project would contribute traffic to the local roadways. However, the project would not substantially alter the vehicle classifications mix on local or regional roadways, nor would the project alter the speed on an existing roadway or create a new roadway. Thus, the primary factor affecting off-site noise levels would be increased traffic volumes.

While changes in noise levels would occur along any roadway where project-related traffic occurs, for noise assessment purposes, noise level increases are assumed to be greatest nearest the project site, as this location would represent the greatest concentration of project-related traffic. As discussed in Section 2.1, noise impacts would be significance if, as a direct result of the project, (1) noise levels for any existing or planned development will exceed the noise levels considered compatible for that use as identified in Table 1, or (2) noise levels which already exceed the levels considered compatible for that use are increased by 3 dB or more.

Based on the ITE Trip Generation Manual 11th Edition, the project would generate 7.20 trips per unit. The project proposes 52 units which would generate a total of 374 daily trips (Linscott, Law & Greenspan, Engineers 2024). A 3 dB increase in noise levels would occur when there is a doubling of traffic volumes on a roadway. Typically, a project would have to double the traffic volume on a roadway in order to have a significant direct noise increase of 3 dB or more or to be major contributor to the cumulative traffic volumes. As shown in Table 3, the existing traffic volume on Mission Gorge Road is 12,877 ADT. Adding 374 trips to Mission Gorge Road would increase noise levels by 0.1 dB, which would not be an audible change in noise levels. Therefore, operational roadway noise would not generate a substantial permanent increase in ambient noise levels for off-site noise sensitive land uses, and impacts would be less than significant.

5.3 On-Site Noise Analysis
On-site generated noise is regulated by the City’s Municipal Code, Title 5 Health and Safety, Chapter 5.04 Noise Abatement and Control. Section 5.04.040 of the City’s Municipal Code states that “it is unlawful for any person to make, continue, or cause to be made or continued, within the limits of the City, any disturbing, excessive or offensive noise which causes discomfort or annoyance to reasonable persons of normal sensitivity residing in the area.” Section 5.04.040 also provides the following requirements for HVAC units:

Mr. Troy Friedeck

Page 22 ends

January 20, 2025
Additionally, in accordance with the Noise Element of the General Plan, the noise level threshold is 65 dB(A) Leq at the property line. Using the parameters discussed in Section 4.3, property line noise levels due to HVAC units were modeled using SoundPLAN. The modeling results are summarized in Table 6. HVAC noise contours are shown in Figure 7. SoundPLAN data is contained in Attachment 4.

As shown in Table 6, property line noise levels would range from 39 to 56 dB(A) Leq. This is a worst-case analysis that assumes all units would operate at 100 percent capacity (i.e., continuously without cycling off) during the daytime and nighttime hours. Noise levels would not exceed 65 dB(A) Leq. Noise at this level would not be considered a noise disturbance. The units would be operated in accordance with the requirements of the City’s Municipal Code.

Table 6
HVAC Noise Levels at Off-Site Receivers
[dB(A) Leq]
Receiver Land Use Designation HVAC Noise Level
1 R14 (Medium-High Density Residential) 44
2 R14 (Medium-High Density Residential) 46
3 R14 (Medium-High Density Residential) 45
4 R14 (Medium-High Density Residential) 43
5 R7 (Medium Density Residential) 41
6 R7 (Medium Density Residential) 56
7 R7 (Medium Density Residential) 51
8 R7 (Medium Density Residential) 50
9 GC (General Commercial) 51
10 GC (General Commercial) 53
11 GC (General Commercial) 51
12 GC (General Commercial) 48
13 R7 (Medium Density Residential) 39
14 R7 (Medium Density Residential) 42
15 R7 (Medium Density Residential) 42
dB(A) Leq = A-weighted decibels equivalent noise level
HVAC = heating, ventilation, and air conditioning

5.4 Off-Site Car Wash Noise
A car wash is located adjacent to the project site to the northeast. The requirements of the City’s Municipal Code apply to operations at the car wash. The car wash is temporarily closed but would potentially be reopened after renovations. An Operational Noise Evaluation of the car wash was conducted by Ldn Consulting, Inc. to determine estimated noise levels from existing and proposed car wash operations. The analysis concluded that the existing car wash operational noise levels comply with the noise standards at the property lines and no substantial permanent noise increase is anticipated (Ldn Consulting, Inc. 2024). Therefore, the car wash would not expose on-site receptors to ambient noise levels in excess of standards established in the City’s General Plan, and impacts would be less than significant.

FIGURE 7
HVAC Noise Contours
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1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 MIRABELLE LN

DOVE ST

WEST HILLS PKY

LAURELHEIGHTS
DR

WREN ST

MISSION GORGE RD

BELLAMONT PASS

BASSETT LN

LAUREL CT
A
U
B
REY
GLE
N

MIRABELLE CT

ROSEMOND LN

CLARE LN

SAGE CT

HISER LN

DOVE ST

WEST HILLS PKY

LAURELHEIGHTS
DR

WREN ST

MISSION GORGE RD

BELLAMONT PASS

BASSETT LN

LAUREL CT
A
U
B
REY
GLE
N

MIRABELLE CT

ROSEMOND LN

CLARE LN

SAGE CT

HISER LN

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January 20, 2025

6.0 Conclusions
Noise impacts due to construction and operation of the project were assessed in accordance with standards established in the City’s General Plan Noise Element and the City’s Municipal Code. As discussed in this analysis, construction noise levels are anticipated to range from 63 to 74 dB(A) Leq at the adjacent properties. Although the existing adjacent uses would be exposed to construction noise levels that could be heard above ambient conditions, the exposure would be temporary. Additionally, the project would be subject to Standard Project Condition No. 4 – Noise, items 1 through 4 (refer to Section 1.1). Compliance with this condition would reduce construction noise impacts to less than significant. As construction activities associated with the project would comply with requirements of the Noise Abatement and Control Ordinance, impacts associated with temporary increases in noise levels during construction would be less than significant.

With the exception of Receivers 1 and 2 which are located on the northern side of the northernmost buildings closest to Mission Gorge Road, exterior noise levels would not exceed the “normally acceptable” noise level limit of 65 CNEL.

However, for Receivers 1 and 2, there are no proposed exterior use areas on the northern sides of those buildings.

Patios would be located on the southern side of those buildings shielded from Mission Gorge Road. Exterior noise levels would not exceed the “normally acceptable” noise level limit of 65 CNEL at any proposed exterior use areas.

Therefore, the project would not expose receivers to exterior noise levels in excess of standards established in the City’s General Plan, and impacts would be less than significant.

Standard light-frame construction would reduce exterior to interior noise levels by at least 20 dB. For the two units located adjacent to Mission Gorge Road (Receivers 1 and 2), noise levels would be up to 69 CNEL and building components with an STC rating of up to 24 would be required. Standard walls and roofs typically have STC ratings greater than 40, and therefore would achieve the required noise reduction. In order to achieve an interior noise level of 45 CNEL or less in the units closest to Mission Gorge Road, windows with an STC of 24 or greater would be required. The inclusion of windows with an STC of 24 in the two units closest to Mission Gorge Road shall be a project condition of approval (see Standard Condition No. 4, item 5). Therefore, the project would not expose receivers to interior noise levels in excess of standards established in the General Plan, and impacts would be less than significant.

The project would contribute traffic to the local roadways. As calculated in this analysis, an increase of 374 project-generated trips on Mission Gorge Road would result in a noise increase of 0.1 dB or less, which would not be an audible change in noise levels. Therefore, operational roadway noise would not generate a substantial permanent increase in ambient noise levels for off-site noise sensitive land uses, and impacts would be less than significant.

Property line noise levels due to on-site HVAC equipment would range from 39 to 56 dB(A) Leq. Noise at this level would not be considered a noise disturbance. The units would be operated in accordance with the requirements of the City’s Municipal Code. Therefore, operational HVAC noise would not generate a substantial permanent increase in ambient noise levels for off-site noise sensitive land uses in excess of standards established in the City’s General Plan, and impacts would be less than significant.

Mr. Troy Friedeck

Page 25 ends

January 20, 2025
If you have any questions about the results of this analysis, please contact me at [email protected] or (619) 308-9333 extension 177.

Sincerely,
Jessica Fleming
Senior Noise Analyst
JLF:sh:jg
Attachments

7.0 References Cited
California Department of Transportation (Caltrans)
2013 Technical Noise Supplement. November.
2021 Traffic Census Program. Truck Traffic: Annual Average Daily Truck Traffic. Accessed at https://dot.ca.gov/programs/traffic-operations/census.

CR Associates
2021 VMT Analysis Data and Highway Load _1299 shapefile. Provided to Jesse Fleming, RECON. May 27.

Federal Highway Administration (FHWA)
2006 Roadway Construction Noise Model User’s Guide. FHWA-HEP-05-054, SOT-VNTSC-FHWA-05-01. Final Report. January.
2008 Roadway Construction Noise Mode, V1.1. Washington, DC. 2011 Highway Traffic Noise: Analysis and Abatement Guidance. FHWA-HEP-10-025. December.

Federal Transit Administration (FTA)
2006 Transit Noise and Vibration Impact Assessment. Washington, DC. May.

Ldn Consulting Inc.
2024 Operational Noise Evaluation of the adjacent Car Wash at the Aubrey Glen Residential Development – City of Santee. December 17, 2024.

Linscott, Law & Greenspan Engineers
2024 Traffic Analysis Intake Form. LLG Ref. 3-24-3939.

Navcon Engineering, Inc.
2018 SoundPLAN Essential version 4.1.

Santee, City of
2003 Santee General Plan.
2022 Draft City of Santee Housing Element Rezone Program Implementation PEIR. SCH #2021100263. June 17.

ATTACHMENTS

ATTACHMENT 1
HVAC Specifications

10174 Mission Gorge Condos
SoundPLAN Data - HVAC
Noise
Source name Reference Level Cwall CI CT
dB(A) dB(A) dB(A) dB(A)
HVAC1 Lw/unit 75 - - -
HVAC2 Lw/unit 75 - - -
HVAC3 Lw/unit 75 - - -
HVAC4 Lw/unit 75 - - -
HVAC5 Lw/unit 75 - - -
HVAC6 Lw/unit 75 - - -
HVAC7 Lw/unit 75 - - -
HVAC8 Lw/unit 75 - - -
HVAC9 Lw/unit 75 - - -
HVAC10 Lw/unit 75 - - -
HVAC11 Lw/unit 75 - - -
HVAC12 Lw/unit 75 - - -
HVAC13 Lw/unit 75 - - -
HVAC14 Lw/unit 75 - - -
HVAC15 Lw/unit 75 - - -
HVAC16 Lw/unit 75 - - -
HVAC17 Lw/unit 75 - - -
HVAC18 Lw/unit 75 - - -
HVAC19 Lw/unit 75 - - -
HVAC20 Lw/unit 75 - - -
HVAC21 Lw/unit 75 - - -
HVAC22 Lw/unit 75 - - -
HVAC23 Lw/unit 75 - - -
HVAC24 Lw/unit 75 - - -
HVAC25 Lw/unit 75 - - -
HVAC26 Lw/unit 75 - - -
HVAC27 Lw/unit 75 - - -
HVAC28 Lw/unit 75 - - -
HVAC29 Lw/unit 75 - - -
HVAC30 Lw/unit 75 - - -
HVAC31 Lw/unit 75 - - -
HVAC32 Lw/unit 75 - - -
HVAC33 Lw/unit 75 - - -
HVAC34 Lw/unit 75 - - -
HVAC35 Lw/unit 75 - - -
HVAC36 Lw/unit 75 - - -
HVAC37 Lw/unit 75 - - -
HVAC38 Lw/unit 75 - - -
HVAC39 Lw/unit 75 - - -
HVAC40 Lw/unit 75 - - -
HVAC41 Lw/unit 75 - - -
HVAC42 Lw/unit 75 - - -
HVAC43 Lw/unit 75 - - -
HVAC44 Lw/unit 75 - - -
HVAC45 Lw/unit 75 - - -
HVAC46 Lw/unit 75 - - -
HVAC47 Lw/unit 75 - - -
HVAC48 Lw/unit 75 - - -
HVAC49 Lw/unit 75 - - -
HVAC50 Lw/unit 75 - - -
HVAC51 Lw/unit 75 - - -
HVAC52 Lw/unit 75 - - -
Corrections
HVAC
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
Noise
No. X Y Height Level
m dB(A)
1 497352.13 3633214.73 107.36 30.6
2 497348.10 3633177.67 108.17 33.7
3 497339.51 3633130.66 108.80 33.4
4 497333.78 3633100.86 109.71 37.2
5 497333.96 3633075.08 110.72 35.1
6 497374.75 3633057.52 113.16 40.3
7 497418.12 3633049.90 113.11 48.3
8 497452.06 3633066.01 110.62 50.4
9 497460.05 3633103.76 108.00 46.4
10 497436.64 3633140.29 107.74 46.1
11 497418.64 3633160.98 106.35 42.5
12 497424.66 3633197.39 104.73 37.4
13 497499.27 3633166.19 105.15 32.0
14 497489.78 3633106.95 107.84 38.1
15 497481.51 3633061.26 111.14 37.4
Coordinates
(meters)
Receivers
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
Noise
Source name Level
dB(A)
1 1.Fl 30.6 0.0
HVAC1 16.8
HVAC2 17.6
HVAC3 10.7
HVAC4 11.1
HVAC5 21.2
HVAC6 12.7
HVAC7 20.2
HVAC8 18.1
HVAC9 19.4
HVAC10 15.9
HVAC11 9.3
HVAC12 8.9
HVAC13 23.2
HVAC14 17.4
HVAC15 9.8
HVAC16 8.6
HVAC17 21.3
HVAC18 11.5
HVAC19 14.2
HVAC20 7.5
HVAC21 9.0
HVAC22 7.6
HVAC23 7.8
HVAC24 5.9
HVAC25 6.2
HVAC26 5.7
HVAC27 5.2
HVAC28 3.6
HVAC29 4.9
HVAC30 2.8
HVAC31 3.3
HVAC32 3.1
HVAC33 4.4
HVAC34 4.3
HVAC35 4.3
HVAC36 3.8
HVAC37 6.8
HVAC38 4.0
HVAC39 6.3
HVAC40 3.4
HVAC41 7.0
HVAC42 5.2
HVAC43 5.9
HVAC44 3.3
HVAC45 3.4
HVAC46 0.5
HVAC47 2.3
HVAC48 2.3
HVAC49 3.1
HVAC50 1.5
HVAC51 3.5
HVAC52 -1.1
2 1.Fl 33.7 0.0
HVAC1 20.8
HVAC2 29.8
HVAC3 9.0
HVAC4 10.2
HVAC5 11.4
HVAC6 12.0
HVAC7 17.3
HVAC8 19.6
HVAC9 17.6
HVAC10 18.4
HVAC11 11.0
HVAC12 11.5
HVAC13 23.3
HVAC14 18.3
HVAC15 15.7
HVAC16 12.2
HVAC17 20.1
HVAC18 16.5
HVAC19 23.8
HVAC20 17.8
HVAC21 10.2
HVAC22 10.0
HVAC23 10.8
HVAC24 10.2
HVAC25 7.6
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC26 5.1
HVAC27 5.4
HVAC28 3.0
HVAC29 5.6
HVAC30 4.7
HVAC31 4.5
HVAC32 6.7
HVAC33 6.6
HVAC34 7.6
HVAC35 6.3
HVAC36 7.2
HVAC37 9.3
HVAC38 6.0
HVAC39 7.7
HVAC40 6.1
HVAC41 8.0
HVAC42 8.7
HVAC43 7.8
HVAC44 6.6
HVAC45 6.3
HVAC46 3.1
HVAC47 3.9
HVAC48 3.2
HVAC49 5.8
HVAC50 3.9
HVAC51 4.7
HVAC52 0.2
3 1.Fl 33.4 0.0
HVAC1 15.0
HVAC2 8.8
HVAC3 5.7
HVAC4 4.3
HVAC5 9.4
HVAC6 7.6
HVAC7 11.3
HVAC8 13.2
HVAC9 20.5
HVAC10 21.5
HVAC11 9.5
HVAC12 10.9
HVAC13 26.5
HVAC14 18.0
HVAC15 9.4
HVAC16 9.4
HVAC17 18.8
HVAC18 20.8
HVAC19 21.5
HVAC20 18.1
HVAC21 13.6
HVAC22 14.7
HVAC23 14.4
HVAC24 13.3
HVAC25 11.4
HVAC26 9.0
HVAC27 7.4
HVAC28 6.6
HVAC29 7.6
HVAC30 4.2
HVAC31 6.0
HVAC32 6.3
HVAC33 8.6
HVAC34 8.2
HVAC35 6.8
HVAC36 10.1
HVAC37 13.0
HVAC38 9.7
HVAC39 12.0
HVAC40 10.4
HVAC41 11.6
HVAC42 16.9
HVAC43 16.6
HVAC44 26.5
HVAC45 16.5
HVAC46 10.5
HVAC47 5.5
HVAC48 5.4
HVAC49 7.3
HVAC50 4.7
HVAC51 5.4
HVAC52 1.8
4 1.Fl 37.2 0.0
HVAC1 11.9
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC2 11.3
HVAC3 4.0
HVAC4 1.5
HVAC5 8.2
HVAC6 6.4
HVAC7 10.2
HVAC8 13.4
HVAC9 11.5
HVAC10 9.6
HVAC11 6.6
HVAC12 7.2
HVAC13 13.4
HVAC14 11.7
HVAC15 9.8
HVAC16 8.8
HVAC17 20.0
HVAC18 28.4
HVAC19 26.8
HVAC20 18.1
HVAC21 8.7
HVAC22 9.8
HVAC23 10.4
HVAC24 7.4
HVAC25 7.6
HVAC26 6.8
HVAC27 5.6
HVAC28 3.0
HVAC29 9.2
HVAC30 10.3
HVAC31 10.1
HVAC32 7.9
HVAC33 7.6
HVAC34 12.0
HVAC35 13.0
HVAC36 12.5
HVAC37 16.1
HVAC38 16.9
HVAC39 16.2
HVAC40 11.3
HVAC41 27.8
HVAC42 31.0
HVAC43 22.0
HVAC44 27.8
HVAC45 28.9
HVAC46 6.5
HVAC47 7.5
HVAC48 7.5
HVAC49 7.7
HVAC50 5.4
HVAC51 6.8
HVAC52 3.5
5 1.Fl 35.1 0.0
HVAC1 8.8
HVAC2 8.6
HVAC3 5.1
HVAC4 0.8
HVAC5 7.2
HVAC6 3.9
HVAC7 9.4
HVAC8 10.3
HVAC9 11.9
HVAC10 12.2
HVAC11 6.7
HVAC12 5.4
HVAC13 11.7
HVAC14 9.9
HVAC15 9.0
HVAC16 8.3
HVAC17 12.3
HVAC18 9.9
HVAC19 25.2
HVAC20 27.2
HVAC21 14.7
HVAC22 16.7
HVAC23 10.6
HVAC24 9.7
HVAC25 7.0
HVAC26 5.8
HVAC27 4.1
HVAC28 2.5
HVAC29 6.3
HVAC30 6.0
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC31 4.1
HVAC32 6.7
HVAC33 8.6
HVAC34 8.7
HVAC35 8.3
HVAC36 7.2
HVAC37 14.3
HVAC38 9.7
HVAC39 7.9
HVAC40 15.3
HVAC41 13.6
HVAC42 17.7
HVAC43 13.9
HVAC44 28.0
HVAC45 26.6
HVAC46 29.0
HVAC47 7.1
HVAC48 7.1
HVAC49 8.5
HVAC50 4.7
HVAC51 7.7
HVAC52 4.5
6 1.Fl 40.3 0.0
HVAC1 8.6
HVAC2 8.4
HVAC3 5.9
HVAC4 4.6
HVAC5 5.6
HVAC6 4.9
HVAC7 8.7
HVAC8 10.4
HVAC9 6.6
HVAC10 10.5
HVAC11 7.7
HVAC12 6.0
HVAC13 11.2
HVAC14 13.2
HVAC15 8.9
HVAC16 7.8
HVAC17 14.0
HVAC18 17.3
HVAC19 20.2
HVAC20 30.1
HVAC21 11.7
HVAC22 10.8
HVAC23 14.6
HVAC24 10.1
HVAC25 10.0
HVAC26 5.3
HVAC27 6.5
HVAC28 4.6
HVAC29 10.8
HVAC30 9.0
HVAC31 10.1
HVAC32 9.5
HVAC33 14.0
HVAC34 9.8
HVAC35 10.0
HVAC36 9.3
HVAC37 10.1
HVAC38 11.8
HVAC39 11.0
HVAC40 20.1
HVAC41 11.9
HVAC42 14.2
HVAC43 13.4
HVAC44 18.7
HVAC45 18.0
HVAC46 39.1
HVAC47 16.8
HVAC48 18.0
HVAC49 28.0
HVAC50 12.9
HVAC51 12.4
HVAC52 8.6
7 1.Fl 48.3 0.0
HVAC1 -0.6
HVAC2 1.8
HVAC3 0.6
HVAC4 1.6
HVAC5 3.3
HVAC6 5.1
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC7 4.6
HVAC8 2.4
HVAC9 4.2
HVAC10 5.7
HVAC11 3.2
HVAC12 3.3
HVAC13 5.2
HVAC14 5.3
HVAC15 7.0
HVAC16 7.5
HVAC17 6.3
HVAC18 8.5
HVAC19 7.1
HVAC20 7.7
HVAC21 8.8
HVAC22 11.2
HVAC23 8.4
HVAC24 13.1
HVAC25 10.8
HVAC26 12.7
HVAC27 12.5
HVAC28 7.3
HVAC29 11.7
HVAC30 12.2
HVAC31 12.4
HVAC32 13.1
HVAC33 16.4
HVAC34 12.9
HVAC35 12.8
HVAC36 11.5
HVAC37 11.2
HVAC38 12.2
HVAC39 11.3
HVAC40 13.1
HVAC41 9.6
HVAC42 11.0
HVAC43 12.4
HVAC44 11.8
HVAC45 13.1
HVAC46 32.3
HVAC47 41.8
HVAC48 44.5
HVAC49 39.3
HVAC50 40.5
HVAC51 33.5
HVAC52 19.0
8 1.Fl 50.4 0.0
HVAC1 1.8
HVAC2 3.6
HVAC3 2.8
HVAC4 3.9
HVAC5 3.1
HVAC6 2.9
HVAC7 3.7
HVAC8 2.5
HVAC9 3.4
HVAC10 4.4
HVAC11 4.3
HVAC12 6.1
HVAC13 4.0
HVAC14 4.5
HVAC15 5.4
HVAC16 5.7
HVAC17 4.9
HVAC18 5.6
HVAC19 5.9
HVAC20 6.6
HVAC21 5.6
HVAC22 5.7
HVAC23 8.2
HVAC24 8.2
HVAC25 8.6
HVAC26 13.3
HVAC27 11.3
HVAC28 28.4
HVAC29 16.1
HVAC30 20.5
HVAC31 18.4
HVAC32 22.5
HVAC33 15.2
HVAC34 14.9
HVAC35 14.4
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC36 13.6
HVAC37 11.1
HVAC38 13.3
HVAC39 13.7
HVAC40 15.0
HVAC41 9.1
HVAC42 9.2
HVAC43 9.1
HVAC44 26.3
HVAC45 26.7
HVAC46 17.8
HVAC47 16.7
HVAC48 16.1
HVAC49 18.2
HVAC50 22.0
HVAC51 24.1
HVAC52 50.3
9 1.Fl 46.4 0.0
HVAC1 5.4
HVAC2 5.4
HVAC3 6.4
HVAC4 10.0
HVAC5 6.9
HVAC6 7.5
HVAC7 5.6
HVAC8 5.6
HVAC9 6.3
HVAC10 6.5
HVAC11 8.4
HVAC12 9.1
HVAC13 7.0
HVAC14 5.9
HVAC15 9.6
HVAC16 9.5
HVAC17 6.6
HVAC18 7.2
HVAC19 7.2
HVAC20 7.3
HVAC21 10.4
HVAC22 8.3
HVAC23 12.1
HVAC24 13.0
HVAC25 17.9
HVAC26 34.1
HVAC27 20.0
HVAC28 43.4
HVAC29 41.9
HVAC30 27.7
HVAC31 25.9
HVAC32 20.7
HVAC33 20.4
HVAC34 22.4
HVAC35 17.2
HVAC36 26.1
HVAC37 19.8
HVAC38 16.9
HVAC39 18.9
HVAC40 12.6
HVAC41 17.3
HVAC42 12.0
HVAC43 12.6
HVAC44 9.8
HVAC45 11.3
HVAC46 7.3
HVAC47 10.2
HVAC48 10.1
HVAC49 8.9
HVAC50 12.5
HVAC51 11.6
HVAC52 29.5
10 1.Fl 46.1 0.0
HVAC1 9.5
HVAC2 11.3
HVAC3 16.7
HVAC4 22.7
HVAC5 15.4
HVAC6 18.6
HVAC7 10.7
HVAC8 9.9
HVAC9 12.2
HVAC10 15.4
HVAC11 16.7
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC12 21.9
HVAC13 10.9
HVAC14 11.5
HVAC15 17.0
HVAC16 17.6
HVAC17 11.7
HVAC18 11.8
HVAC19 9.9
HVAC20 9.4
HVAC21 17.3
HVAC22 16.8
HVAC23 18.6
HVAC24 21.8
HVAC25 27.7
HVAC26 41.4
HVAC27 44.0
HVAC28 19.5
HVAC29 13.8
HVAC30 12.8
HVAC31 12.8
HVAC32 10.9
HVAC33 11.8
HVAC34 13.8
HVAC35 13.4
HVAC36 16.7
HVAC37 14.0
HVAC38 13.4
HVAC39 13.3
HVAC40 11.6
HVAC41 12.6
HVAC42 9.4
HVAC43 9.5
HVAC44 7.8
HVAC45 9.1
HVAC46 6.4
HVAC47 8.3
HVAC48 8.2
HVAC49 7.0
HVAC50 11.1
HVAC51 11.7
HVAC52 6.7
11 1.Fl 42.5 0.0
HVAC1 10.7
HVAC2 11.8
HVAC3 15.6
HVAC4 21.0
HVAC5 22.7
HVAC6 27.5
HVAC7 13.5
HVAC8 13.5
HVAC9 15.5
HVAC10 18.0
HVAC11 25.6
HVAC12 29.3
HVAC13 17.6
HVAC14 15.9
HVAC15 39.2
HVAC16 26.3
HVAC17 12.5
HVAC18 12.2
HVAC19 9.9
HVAC20 11.0
HVAC21 16.6
HVAC22 15.9
HVAC23 28.6
HVAC24 34.4
HVAC25 33.5
HVAC26 17.8
HVAC27 21.1
HVAC28 12.9
HVAC29 11.5
HVAC30 10.4
HVAC31 11.0
HVAC32 11.2
HVAC33 9.1
HVAC34 11.6
HVAC35 11.6
HVAC36 13.2
HVAC37 13.4
HVAC38 11.6
HVAC39 12.4
HVAC40 9.9
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC41 12.7
HVAC42 10.3
HVAC43 12.3
HVAC44 9.7
HVAC45 13.0
HVAC46 4.8
HVAC47 18.7
HVAC48 18.6
HVAC49 19.0
HVAC50 7.3
HVAC51 9.7
HVAC52 4.9
12 1.Fl 37.4 0.0
HVAC1 13.2
HVAC2 18.0
HVAC3 25.6
HVAC4 29.4
HVAC5 29.1
HVAC6 27.2
HVAC7 23.5
HVAC8 15.7
HVAC9 12.1
HVAC10 11.5
HVAC11 16.8
HVAC12 16.5
HVAC13 9.5
HVAC14 10.0
HVAC15 15.2
HVAC16 18.9
HVAC17 8.7
HVAC18 8.8
HVAC19 4.2
HVAC20 6.6
HVAC21 10.2
HVAC22 14.3
HVAC23 26.2
HVAC24 27.4
HVAC25 26.0
HVAC26 24.8
HVAC27 26.2
HVAC28 12.6
HVAC29 6.9
HVAC30 7.3
HVAC31 5.3
HVAC32 5.6
HVAC33 6.7
HVAC34 7.5
HVAC35 7.9
HVAC36 8.5
HVAC37 8.7
HVAC38 7.1
HVAC39 7.8
HVAC40 6.5
HVAC41 7.7
HVAC42 6.4
HVAC43 7.5
HVAC44 4.3
HVAC45 5.9
HVAC46 2.7
HVAC47 15.0
HVAC48 14.9
HVAC49 14.5
HVAC50 3.1
HVAC51 6.1
HVAC52 3.3
13 1.Fl 32.0 0.0
HVAC1 5.8
HVAC2 9.1
HVAC3 8.6
HVAC4 11.5
HVAC5 8.6
HVAC6 8.5
HVAC7 6.9
HVAC8 5.1
HVAC9 5.4
HVAC10 5.5
HVAC11 8.7
HVAC12 9.1
HVAC13 7.0
HVAC14 5.9
HVAC15 10.0
HVAC16 9.6
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC17 4.0
HVAC18 4.6
HVAC19 5.1
HVAC20 3.4
HVAC21 6.6
HVAC22 6.7
HVAC23 9.2
HVAC24 9.2
HVAC25 10.1
HVAC26 22.2
HVAC27 13.5
HVAC28 29.8
HVAC29 9.5
HVAC30 9.4
HVAC31 8.7
HVAC32 7.8
HVAC33 5.9
HVAC34 7.4
HVAC35 6.7
HVAC36 7.3
HVAC37 5.3
HVAC38 4.2
HVAC39 4.1
HVAC40 2.7
HVAC41 4.7
HVAC42 3.7
HVAC43 3.8
HVAC44 1.5
HVAC45 2.1
HVAC46 -1.5
HVAC47 2.5
HVAC48 2.6
HVAC49 -0.4
HVAC50 8.7
HVAC51 5.5
HVAC52 23.2
14 1.Fl 38.1 0.0
HVAC1 2.2
HVAC2 6.0
HVAC3 7.6
HVAC4 20.6
HVAC5 6.2
HVAC6 8.3
HVAC7 3.9
HVAC8 3.0
HVAC9 3.9
HVAC10 4.0
HVAC11 7.2
HVAC12 11.7
HVAC13 4.2
HVAC14 4.4
HVAC15 4.3
HVAC16 4.4
HVAC17 4.9
HVAC18 8.0
HVAC19 6.8
HVAC20 6.2
HVAC21 6.1
HVAC22 6.3
HVAC23 9.7
HVAC24 10.7
HVAC25 11.8
HVAC26 16.4
HVAC27 12.8
HVAC28 34.8
HVAC29 30.0
HVAC30 29.4
HVAC31 21.5
HVAC32 17.7
HVAC33 13.3
HVAC34 17.1
HVAC35 12.7
HVAC36 17.6
HVAC37 12.6
HVAC38 12.1
HVAC39 13.1
HVAC40 9.6
HVAC41 11.9
HVAC42 8.5
HVAC43 10.0
HVAC44 7.3
HVAC45 8.0
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC46 4.8
HVAC47 9.0
HVAC48 7.7
HVAC49 10.1
HVAC50 14.9
HVAC51 15.7
HVAC52 28.2
15 1.Fl 37.4 0.0
HVAC1 2.2
HVAC2 2.4
HVAC3 6.0
HVAC4 10.0
HVAC5 3.0
HVAC6 2.1
HVAC7 1.8
HVAC8 1.8
HVAC9 2.0
HVAC10 4.0
HVAC11 3.4
HVAC12 5.8
HVAC13 2.4
HVAC14 2.6
HVAC15 3.9
HVAC16 3.9
HVAC17 3.3
HVAC18 5.9
HVAC19 3.6
HVAC20 4.0
HVAC21 3.4
HVAC22 3.5
HVAC23 7.1
HVAC24 7.1
HVAC25 8.6
HVAC26 10.6
HVAC27 12.4
HVAC28 29.4
HVAC29 16.4
HVAC30 29.5
HVAC31 17.4
HVAC32 29.3
HVAC33 14.0
HVAC34 12.5
HVAC35 12.9
HVAC36 13.3
HVAC37 8.6
HVAC38 13.0
HVAC39 11.3
HVAC40 10.4
HVAC41 9.8
HVAC42 9.8
HVAC43 7.3
HVAC44 22.8
HVAC45 23.0
HVAC46 14.0
HVAC47 10.7
HVAC48 10.3
HVAC49 11.8
HVAC50 13.1
HVAC51 14.3
HVAC52 33.1
Contributions

ATTACHMENT 2
SoundPLAN Data – Construction Noise
10174 Mission Gorge Condos
SoundPLAN Data - Construction
Noise
Source name Reference Level Cwall CI CT
dB(A) dB(A) dB(A) dB(A)
Construction Lw/unit 116.3 - - -
Corrections
Construction
10174 Mission Gorge Condos
SoundPLAN Data - Construction
Noise
No. X Y Height Level
(meters) dB(A)
1 497352.13 3633214.73 107.36 70.2
2 497348.10 3633177.67 108.17 72.3
3 497339.51 3633130.66 108.80 72.2
4 497333.78 3633100.86 109.71 71.3
5 497333.96 3633075.08 110.72 69.6
6 497374.75 3633057.52 113.16 73.4
7 497418.12 3633049.90 113.11 73.0
8 497452.06 3633066.01 110.62 72.5
9 497460.05 3633103.76 108.06 72.7
10 497436.64 3633140.29 106.85 74.4
11 497418.64 3633160.98 106.35 74.0
12 497424.66 3633197.39 105.43 72.6
13 497499.27 3633166.19 105.15 63.2
14 497489.78 3633106.95 107.84 65.9
15 497481.51 3633061.26 111.14 65.6
Coordinates
(meters)
Receivers

ATTACHMENT 3
SoundPLAN Data – Vehicle Traffic Noise
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
Traffic values Control Constr. Affect. Gradient
Station ADT Vehicles type Vehicle name day evening night Speed device Speed veh. Road surface Min / Max km Veh/24h Veh/h Veh/h Veh/h km/h km/h % %
Mission Gorge Road Traffic direction: In entry direction 0+000 16614 Total - 1066 554 240 - none - - Average (of DGAC and PCC) -3.75 0+000 16614 Automobiles - 1017 529 229 80 none - - Average (of DGAC and PCC) -3.75 0+000 16614 Medium trucks - 21 11 5 80 none - - Average (of DGAC and PCC) -3.75 0+000 16614 Heavy trucks - 6 3 1 80 none - - Average (of DGAC and PCC) -3.75 0+000 16614 Buses - 11 6 2 80 none - - Average (of DGAC and PCC) -3.75 0+000 16614 Motorcycles - 11 6 2 80 none - - Average (of DGAC and PCC) -3.75 0+000 16614 Auxiliary vehicle - - - - - none - - Average (of DGAC and PCC) -3.75 0+872 - - - - - -
SR-52 NW-bound Traffic direction: In entry direction
0+000 67182 Total - 4311 2240 970 - none - - Average (of DGAC and PCC) -1.533333333 0+000 67182 Automobiles - 4113 2137 925 105 none - - Average (of DGAC and PCC) -1.533333333 0+000 67182 Medium trucks - 86 45 19 105 none - - Average (of DGAC and PCC) -1.533333333 0+000 67182 Heavy trucks - 26 13 6 105 none - - Average (of DGAC and PCC) -1.533333333 0+000 67182 Buses - 43 22 10 105 none - - Average (of DGAC and PCC) -1.533333333 0+000 67182 Motorcycles - 43 22 10 105 none - - Average (of DGAC and PCC) -1.533333333 0+000 67182 Auxiliary vehicle - - - - - none - - Average (of DGAC and PCC) -1.533333333 1+004 - - - - - -
SR-52 SE-bound Traffic direction: In entry direction
0+000 67182 Total - 4311 2240 970 - none - - Average (of DGAC and PCC) -1.38 0+000 67182 Automobiles - 4113 2137 925 105 none - - Average (of DGAC and PCC) -1.38 0+000 67182 Medium trucks - 86 45 19 105 none - - Average (of DGAC and PCC) -1.38 0+000 67182 Heavy trucks - 26 13 6 105 none - - Average (of DGAC and PCC) -1.38 0+000 67182 Buses - 43 22 10 105 none - - Average (of DGAC and PCC) -1.38 0+000 67182 Motorcycles - 43 22 10 105 none - - Average (of DGAC and PCC) -1.38 0+000 67182 Auxiliary vehicle - - - - - none - - Average (of DGAC and PCC) -1.38 1+048 - - - - - -
Road
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
No. X Y Floor Height Day Evening Night Lden
(meters)
1 497388.09 3633214.76 1.Fl 105.96 64.8 62.0 58.3 66.7
1 497388.09 3633214.76 2.Fl 109.26 66.9 64.0 60.4 68.8
1 497388.09 3633214.76 3.Fl 112.56 67.1 64.3 60.7 69.0
2 497411.50 3633210.57 1.Fl 105.12 64.4 61.5 57.9 66.3
2 497411.50 3633210.57 2.Fl 108.42 66.5 63.6 60.0 68.4
2 497411.50 3633210.57 3.Fl 111.72 67.1 64.2 60.6 69.0
3 497409.89 3633191.03 1.Fl 106.35 58.6 55.8 52.1 60.5
3 497409.89 3633191.03 2.Fl 109.65 61.0 58.2 54.6 62.9
3 497409.89 3633191.03 3.Fl 112.95 62.7 59.8 56.2 64.6
4 497382.92 3633195.63 1.Fl 106.02 57.6 54.8 51.2 59.5
4 497382.92 3633195.63 2.Fl 109.32 60.8 57.9 54.3 62.7
4 497382.92 3633195.63 3.Fl 112.62 62.3 59.5 55.8 64.2
5 497379.85 3633179.40 1.Fl 106.40 50.1 47.2 43.6 52.0
5 497379.85 3633179.40 2.Fl 109.70 54.5 51.7 48.1 56.4
5 497379.85 3633179.40 3.Fl 113.00 56.9 54.1 50.4 58.8
6 497407.06 3633174.96 1.Fl 106.35 52.9 50.1 46.4 54.8
6 497407.06 3633174.96 2.Fl 109.65 56.3 53.5 49.8 58.2
6 497407.06 3633174.96 3.Fl 112.95 58.6 55.8 52.1 60.5
7 497403.35 3633157.04 1.Fl 106.35 50.4 47.6 43.9 52.3
7 497403.35 3633157.04 2.Fl 109.65 54.3 51.4 47.8 56.2
7 497403.35 3633157.04 3.Fl 112.95 57.0 54.1 50.5 58.9
8 497376.38 3633161.40 1.Fl 106.50 48.0 45.1 41.5 49.9
8 497376.38 3633161.40 2.Fl 109.80 52.5 49.7 46.0 54.4
8 497376.38 3633161.40 3.Fl 113.10 55.0 52.2 48.5 56.9
9 497373.96 3633145.49 1.Fl 106.85 44.1 41.3 37.6 46.0
9 497373.96 3633145.49 2.Fl 110.15 48.1 45.3 41.7 50.0
9 497373.96 3633145.49 3.Fl 113.45 51.0 48.2 44.5 52.9
10 497402.06 3633139.36 1.Fl 106.38 49.1 46.2 42.6 51.0 10 497402.06 3633139.36 2.Fl 109.68 53.0 50.2 46.5 54.9 10 497402.06 3633139.36 3.Fl 112.98 55.9 53.1 49.5 57.8 11 497416.91 3633136.77 1.Fl 107.89 55.8 53.0 49.3 57.7 11 497416.91 3633136.77 2.Fl 111.19 58.9 56.0 52.4 60.8 11 497416.91 3633136.77 3.Fl 114.49 60.4 57.6 54.0 62.3 12 497432.82 3633134.27 1.Fl 107.98 56.6 53.8 50.1 58.5 12 497432.82 3633134.27 2.Fl 111.28 59.4 56.5 52.9 61.3 12 497432.82 3633134.27 3.Fl 114.58 60.8 58.0 54.3 62.7 13 497448.56 3633131.12 1.Fl 108.36 57.1 54.3 50.6 59.0 13 497448.56 3633131.12 2.Fl 111.66 59.7 56.9 53.3 61.6 13 497448.56 3633131.12 3.Fl 114.96 61.1 58.3 54.6 63.0 14 497446.94 3633111.02 1.Fl 108.65 51.0 48.1 44.5 52.9 14 497446.94 3633111.02 2.Fl 111.95 54.9 52.1 48.5 56.8 Coordinates
(meters)
Noise Level
dB(A)
Receivers
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
14 497446.94 3633111.02 3.Fl 115.25 57.1 54.3 50.7 59.0 15 497427.33 3633114.41 1.Fl 108.41 45.1 42.3 38.7 47.0 15 497427.33 3633114.41 2.Fl 111.71 48.7 45.8 42.2 50.6 15 497427.33 3633114.41 3.Fl 115.01 50.6 47.8 44.2 52.5 16 497411.82 3633116.67 1.Fl 108.44 41.8 38.9 35.3 43.7 16 497411.82 3633116.67 2.Fl 111.74 45.7 42.9 39.2 47.6 16 497411.82 3633116.67 3.Fl 115.04 48.6 45.8 42.2 50.5 17 497391.96 3633120.47 1.Fl 106.54 40.9 38.0 34.4 42.8 17 497391.96 3633120.47 2.Fl 109.84 44.4 41.5 37.9 46.3 17 497391.96 3633120.47 3.Fl 113.14 45.9 43.1 39.5 47.8 18 497370.81 3633124.58 1.Fl 107.53 41.7 38.9 35.2 43.6 18 497370.81 3633124.58 2.Fl 110.83 45.4 42.5 38.9 47.3 18 497370.81 3633124.58 3.Fl 114.13 48.2 45.4 41.8 50.1 19 497414.25 3633073.07 1.Fl 108.96 37.4 34.5 30.9 39.3 19 497414.25 3633073.07 2.Fl 112.26 41.7 38.8 35.2 43.6 19 497414.25 3633073.07 3.Fl 115.56 44.6 41.7 38.1 46.5 20 497429.75 3633070.09 1.Fl 110.50 45.1 42.2 38.6 47.0 20 497429.75 3633070.09 2.Fl 113.80 49.2 46.3 42.7 51.1 20 497429.75 3633070.09 3.Fl 117.10 51.8 48.9 45.3 53.7 Receivers
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
Source name Day Evening Night CNEL
1 1.Fl 64.8 62.0 58.3 66.7 0.0 0.0 0.0 0.0
Mission Gorge Road 64.6 61.8 58.2 66.5
SR-52 NW-bound 46.6 43.8 40.1 48.5
SR-52 SE-bound 48.6 45.7 42.1 50.5
1 2.Fl 66.9 64.0 60.4 68.8 0.0 0.0 0.0 0.0
Mission Gorge Road 66.6 63.8 60.2 68.5
SR-52 NW-bound 49.6 46.7 43.1 51.5
SR-52 SE-bound 52.1 49.2 45.6 54.0
1 3.Fl 67.1 64.3 60.7 69.0 0.0 0.0 0.0 0.0
Mission Gorge Road 66.8 64.0 60.4 68.7
SR-52 NW-bound 51.1 48.3 44.6 53.0
SR-52 SE-bound 53.5 50.7 47.0 55.4
2 1.Fl 64.4 61.5 57.9 66.3 0.0 0.0 0.0 0.0
Mission Gorge Road 64.2 61.3 57.7 66.1
SR-52 NW-bound 45.7 42.9 39.3 47.6
SR-52 SE-bound 48.2 45.3 41.7 50.1
2 2.Fl 66.5 63.6 60.0 68.4 0.0 0.0 0.0 0.0
Mission Gorge Road 66.2 63.4 59.8 68.2
SR-52 NW-bound 49.6 46.8 43.1 51.5
SR-52 SE-bound 51.6 48.8 45.2 53.5
2 3.Fl 67.1 64.2 60.6 69.0 0.0 0.0 0.0 0.0
Mission Gorge Road 66.7 63.9 60.3 68.6
SR-52 NW-bound 51.0 48.2 44.6 52.9
SR-52 SE-bound 53.7 50.9 47.3 55.6
3 1.Fl 58.6 55.8 52.1 60.5 0.0 0.0 0.0 0.0
Mission Gorge Road 58.0 55.2 51.5 59.9
SR-52 NW-bound 46.0 43.2 39.5 47.9
SR-52 SE-bound 46.9 44.1 40.5 48.8
3 2.Fl 61.0 58.2 54.6 62.9 0.0 0.0 0.0 0.0
Mission Gorge Road 60.1 57.3 53.7 62.0
SR-52 NW-bound 50.1 47.2 43.6 52.0
SR-52 SE-bound 51.4 48.6 44.9 53.3
3 3.Fl 62.7 59.8 56.2 64.6 0.0 0.0 0.0 0.0
Mission Gorge Road 61.7 58.8 55.2 63.6
SR-52 NW-bound 52.0 49.1 45.5 53.9
SR-52 SE-bound 53.7 50.8 47.2 55.6
4 1.Fl 57.6 54.8 51.2 59.5 0.0 0.0 0.0 0.0
Mission Gorge Road 57.5 54.6 51.0 59.4
SR-52 NW-bound 38.1 35.3 31.6 40.0
SR-52 SE-bound 41.9 39.0 35.4 43.8
4 2.Fl 60.8 57.9 54.3 62.7 0.0 0.0 0.0 0.0
Mission Gorge Road 60.6 57.8 54.2 62.5
SR-52 NW-bound 39.4 36.6 32.9 41.3
SR-52 SE-bound 44.9 42.0 38.4 46.8
4 3.Fl 62.3 59.5 55.8 64.2 0.0 0.0 0.0 0.0
Mission Gorge Road 62.1 59.3 55.7 64.0
SR-52 NW-bound 41.8 39.0 35.4 43.7
SR-52 SE-bound 47.3 44.5 40.8 49.2
5 1.Fl 50.1 47.2 43.6 52.0 0.0 0.0 0.0 0.0
Mission Gorge Road 49.7 46.9 43.2 51.6
SR-52 NW-bound 30.2 27.3 23.7 32.1
SR-52 SE-bound 38.3 35.4 31.8 40.2
Level w/o NP
dB(A)
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
5 2.Fl 54.5 51.7 48.1 56.4 0.0 0.0 0.0 0.0
Mission Gorge Road 54.3 51.5 47.9 56.2
SR-52 NW-bound 33.8 31.0 27.3 35.7
SR-52 SE-bound 40.3 37.5 33.8 42.2
5 3.Fl 56.9 54.1 50.4 58.8 0.0 0.0 0.0 0.0
Mission Gorge Road 56.6 53.8 50.2 58.5
SR-52 NW-bound 38.4 35.6 31.9 40.3
SR-52 SE-bound 43.4 40.5 36.9 45.3
6 1.Fl 52.9 50.1 46.4 54.8 0.0 0.0 0.0 0.0
Mission Gorge Road 51.6 48.8 45.2 53.5
SR-52 NW-bound 42.1 39.3 35.6 44.0
SR-52 SE-bound 45.2 42.3 38.7 47.1
6 2.Fl 56.3 53.5 49.8 58.2 0.0 0.0 0.0 0.0
Mission Gorge Road 55.0 52.2 48.6 56.9
SR-52 NW-bound 46.0 43.2 39.5 47.9
SR-52 SE-bound 48.5 45.7 42.0 50.4
6 3.Fl 58.6 55.8 52.1 60.5 0.0 0.0 0.0 0.0
Mission Gorge Road 57.3 54.4 50.8 59.2
SR-52 NW-bound 49.0 46.2 42.6 50.9
SR-52 SE-bound 50.5 47.7 44.1 52.4
7 1.Fl 50.4 47.6 43.9 52.3 0.0 0.0 0.0 0.0
Mission Gorge Road 48.6 45.8 42.1 50.5
SR-52 NW-bound 41.9 39.1 35.4 43.8
SR-52 SE-bound 43.5 40.6 37.0 45.4
7 2.Fl 54.3 51.4 47.8 56.2 0.0 0.0 0.0 0.0
Mission Gorge Road 52.3 49.5 45.9 54.3
SR-52 NW-bound 46.0 43.2 39.5 47.9
SR-52 SE-bound 47.4 44.6 40.9 49.3
7 3.Fl 57.0 54.1 50.5 58.9 0.0 0.0 0.0 0.0
Mission Gorge Road 54.6 51.8 48.2 56.5
SR-52 NW-bound 49.5 46.7 43.1 51.5
SR-52 SE-bound 50.6 47.7 44.1 52.5
8 1.Fl 48.0 45.1 41.5 49.9 0.0 0.0 0.0 0.0
Mission Gorge Road 47.5 44.6 41.0 49.4
SR-52 NW-bound 27.7 24.8 21.2 29.6
SR-52 SE-bound 38.1 35.3 31.7 40.0
8 2.Fl 52.5 49.7 46.0 54.4 0.0 0.0 0.0 0.0
Mission Gorge Road 52.2 49.3 45.7 54.1
SR-52 NW-bound 30.2 27.4 23.8 32.1
SR-52 SE-bound 40.9 38.0 34.4 42.8
8 3.Fl 55.0 52.2 48.5 56.9 0.0 0.0 0.0 0.0
Mission Gorge Road 54.6 51.8 48.2 56.5
SR-52 NW-bound 35.9 33.1 29.4 37.8
SR-52 SE-bound 43.6 40.7 37.1 45.5
9 1.Fl 44.1 41.3 37.6 46.0 0.0 0.0 0.0 0.0
Mission Gorge Road 43.8 40.9 37.3 45.7
SR-52 NW-bound 26.5 23.7 20.0 28.4
SR-52 SE-bound 31.3 28.5 24.9 33.2
9 2.Fl 48.1 45.3 41.7 50.0 0.0 0.0 0.0 0.0
Mission Gorge Road 47.9 45.0 41.4 49.8
SR-52 NW-bound 29.3 26.5 22.8 31.2
SR-52 SE-bound 34.6 31.8 28.1 36.5
9 3.Fl 51.0 48.2 44.5 52.9 0.0 0.0 0.0 0.0
Mission Gorge Road 50.5 47.6 44.0 52.4
SR-52 NW-bound 35.5 32.6 29.0 37.4
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
SR-52 SE-bound 40.3 37.5 33.8 42.2
10 1.Fl 49.1 46.2 42.6 51.0 0.0 0.0 0.0 0.0
Mission Gorge Road 46.7 43.9 40.3 48.6
SR-52 NW-bound 40.6 37.8 34.1 42.5
SR-52 SE-bound 43.4 40.6 36.9 45.3
10 2.Fl 53.0 50.2 46.5 54.9 0.0 0.0 0.0 0.0
Mission Gorge Road 50.7 47.9 44.3 52.6
SR-52 NW-bound 45.4 42.5 38.9 47.3
SR-52 SE-bound 46.7 43.8 40.2 48.6
10 3.Fl 55.9 53.1 49.5 57.8 0.0 0.0 0.0 0.0
Mission Gorge Road 52.9 50.1 46.5 54.8
SR-52 NW-bound 49.7 46.9 43.3 51.6
SR-52 SE-bound 50.1 47.2 43.6 52.0
11 1.Fl 55.8 53.0 49.3 57.7 0.0 0.0 0.0 0.0
Mission Gorge Road 53.5 50.7 47.1 55.4
SR-52 NW-bound 47.5 44.7 41.0 49.4
SR-52 SE-bound 49.9 47.1 43.4 51.8
11 2.Fl 58.9 56.0 52.4 60.8 0.0 0.0 0.0 0.0
Mission Gorge Road 56.2 53.3 49.7 58.1
SR-52 NW-bound 51.5 48.7 45.1 53.4
SR-52 SE-bound 53.4 50.5 46.9 55.3
11 3.Fl 60.4 57.6 54.0 62.3 0.0 0.0 0.0 0.0
Mission Gorge Road 57.3 54.4 50.8 59.2
SR-52 NW-bound 53.6 50.7 47.1 55.5
SR-52 SE-bound 55.3 52.5 48.9 57.2
12 1.Fl 56.6 53.8 50.1 58.5 0.0 0.0 0.0 0.0
Mission Gorge Road 54.3 51.5 47.8 56.2
SR-52 NW-bound 49.1 46.2 42.6 51.0
SR-52 SE-bound 50.3 47.4 43.8 52.2
12 2.Fl 59.4 56.5 52.9 61.3 0.0 0.0 0.0 0.0
Mission Gorge Road 56.7 53.9 50.2 58.6
SR-52 NW-bound 52.2 49.4 45.7 54.1
SR-52 SE-bound 53.7 50.8 47.2 55.6
12 3.Fl 60.8 58.0 54.3 62.7 0.0 0.0 0.0 0.0
Mission Gorge Road 57.8 55.0 51.4 59.7
SR-52 NW-bound 53.8 50.9 47.3 55.7
SR-52 SE-bound 55.5 52.6 49.0 57.4
13 1.Fl 57.1 54.3 50.6 59.0 0.0 0.0 0.0 0.0
Mission Gorge Road 54.9 52.1 48.4 56.8
SR-52 NW-bound 49.3 46.4 42.8 51.2
SR-52 SE-bound 50.8 48.0 44.3 52.7
13 2.Fl 59.7 56.9 53.3 61.6 0.0 0.0 0.0 0.0
Mission Gorge Road 57.2 54.3 50.7 59.1
SR-52 NW-bound 52.2 49.4 45.8 54.1
SR-52 SE-bound 54.0 51.2 47.5 55.9
13 3.Fl 61.1 58.3 54.6 63.0 0.0 0.0 0.0 0.0
Mission Gorge Road 58.3 55.5 51.9 60.2
SR-52 NW-bound 53.9 51.0 47.4 55.8
SR-52 SE-bound 55.6 52.7 49.1 57.5
14 1.Fl 51.0 48.1 44.5 52.9 0.0 0.0 0.0 0.0
Mission Gorge Road 47.5 44.7 41.0 49.4
SR-52 NW-bound 45.0 42.1 38.5 46.9
SR-52 SE-bound 45.8 43.0 39.3 47.7
14 2.Fl 54.9 52.1 48.5 56.8 0.0 0.0 0.0 0.0
Mission Gorge Road 50.7 47.9 44.2 52.6
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
SR-52 NW-bound 49.0 46.1 42.5 50.9
SR-52 SE-bound 50.6 47.8 44.1 52.5
14 3.Fl 57.1 54.3 50.7 59.0 0.0 0.0 0.0 0.0
Mission Gorge Road 52.6 49.8 46.2 54.5
SR-52 NW-bound 51.1 48.3 44.7 53.0
SR-52 SE-bound 53.1 50.3 46.6 55.0
15 1.Fl 45.1 42.3 38.7 47.0 0.0 0.0 0.0 0.0
Mission Gorge Road 39.4 36.5 32.9 41.3
SR-52 NW-bound 38.5 35.6 32.0 40.4
SR-52 SE-bound 42.3 39.4 35.8 44.2
15 2.Fl 48.7 45.8 42.2 50.6 0.0 0.0 0.0 0.0
Mission Gorge Road 42.2 39.3 35.7 44.1
SR-52 NW-bound 41.0 38.2 34.5 42.9
SR-52 SE-bound 46.5 43.6 40.0 48.4
15 3.Fl 50.6 47.8 44.2 52.5 0.0 0.0 0.0 0.0
Mission Gorge Road 44.8 41.9 38.3 46.7
SR-52 NW-bound 42.9 40.1 36.5 44.8
SR-52 SE-bound 48.2 45.4 41.7 50.1
16 1.Fl 41.8 38.9 35.3 43.7 0.0 0.0 0.0 0.0
Mission Gorge Road 37.4 34.6 31.0 39.3
SR-52 NW-bound 36.9 34.0 30.4 38.8
SR-52 SE-bound 36.7 33.8 30.2 38.6
16 2.Fl 45.7 42.9 39.2 47.6 0.0 0.0 0.0 0.0
Mission Gorge Road 40.4 37.5 33.9 42.3
SR-52 NW-bound 41.0 38.1 34.5 42.9
SR-52 SE-bound 41.4 38.5 34.9 43.3
16 3.Fl 48.6 45.8 42.2 50.5 0.0 0.0 0.0 0.0
Mission Gorge Road 43.3 40.5 36.8 45.2
SR-52 NW-bound 43.2 40.4 36.7 45.1
SR-52 SE-bound 44.8 42.0 38.4 46.7
17 1.Fl 40.9 38.0 34.4 42.8 0.0 0.0 0.0 0.0
Mission Gorge Road 40.3 37.4 33.8 42.2
SR-52 NW-bound 28.4 25.5 21.9 30.3
SR-52 SE-bound 29.4 26.6 22.9 31.3
17 2.Fl 44.4 41.5 37.9 46.3 0.0 0.0 0.0 0.0
Mission Gorge Road 43.9 41.1 37.4 45.8
SR-52 NW-bound 30.6 27.8 24.2 32.5
SR-52 SE-bound 32.2 29.4 25.8 34.1
17 3.Fl 45.9 43.1 39.5 47.8 0.0 0.0 0.0 0.0
Mission Gorge Road 44.8 42.0 38.4 46.7
SR-52 NW-bound 35.8 32.9 29.3 37.7
SR-52 SE-bound 37.0 34.1 30.5 38.9
18 1.Fl 41.7 38.9 35.2 43.6 0.0 0.0 0.0 0.0
Mission Gorge Road 41.3 38.5 34.8 43.2
SR-52 NW-bound 25.8 23.0 19.4 27.8
SR-52 SE-bound 29.7 26.9 23.2 31.6
18 2.Fl 45.4 42.5 38.9 47.3 0.0 0.0 0.0 0.0
Mission Gorge Road 45.0 42.2 38.5 46.9
SR-52 NW-bound 28.8 26.0 22.3 30.7
SR-52 SE-bound 32.9 30.0 26.4 34.8
18 3.Fl 48.2 45.4 41.8 50.1 0.0 0.0 0.0 0.0
Mission Gorge Road 47.5 44.7 41.1 49.5
SR-52 NW-bound 35.3 32.5 28.8 37.2
SR-52 SE-bound 38.1 35.2 31.6 40.0
19 1.Fl 37.4 34.5 30.9 39.3 0.0 0.0 0.0 0.0
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - Traffic
Mission Gorge Road 34.6 31.7 28.1 36.5
SR-52 NW-bound 28.5 25.6 22.0 30.4
SR-52 SE-bound 32.8 30.0 26.4 34.7
19 2.Fl 41.7 38.8 35.2 43.6 0.0 0.0 0.0 0.0
Mission Gorge Road 39.3 36.5 32.8 41.2
SR-52 NW-bound 30.9 28.0 24.4 32.8
SR-52 SE-bound 36.9 34.0 30.4 38.8
19 3.Fl 44.6 41.7 38.1 46.5 0.0 0.0 0.0 0.0
Mission Gorge Road 41.0 38.2 34.5 42.9
SR-52 NW-bound 35.7 32.9 29.3 37.6
SR-52 SE-bound 40.9 38.0 34.4 42.8
20 1.Fl 45.1 42.2 38.6 47.0 0.0 0.0 0.0 0.0
Mission Gorge Road 39.0 36.1 32.5 40.9
SR-52 NW-bound 36.9 34.1 30.4 38.8
SR-52 SE-bound 42.8 40.0 36.4 44.7
20 2.Fl 49.2 46.3 42.7 51.1 0.0 0.0 0.0 0.0
Mission Gorge Road 43.1 40.2 36.6 45.0
SR-52 NW-bound 40.3 37.5 33.9 42.2
SR-52 SE-bound 47.1 44.3 40.6 49.0
20 3.Fl 51.8 48.9 45.3 53.7 0.0 0.0 0.0 0.0
Mission Gorge Road 45.1 42.3 38.7 47.0
SR-52 NW-bound 44.2 41.4 37.8 46.1
SR-52 SE-bound 49.6 46.8 43.1 51.5
Contributions
ATTACHMENT 4
SoundPLAN Data – HVAC Noise
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
Noise
Source name Reference Level Cwall CI CT
dB(A) dB(A) dB(A) dB(A)
HVAC1 Lw/unit 75 - - -
HVAC2 Lw/unit 75 - - -
HVAC3 Lw/unit 75 - - -
HVAC4 Lw/unit 75 - - -
HVAC5 Lw/unit 75 - - -
HVAC6 Lw/unit 75 - - -
HVAC7 Lw/unit 75 - - -
HVAC8 Lw/unit 75 - - -
HVAC9 Lw/unit 75 - - -
HVAC10 Lw/unit 75 - - -
HVAC11 Lw/unit 75 - - -
HVAC12 Lw/unit 75 - - -
HVAC13 Lw/unit 75 - - -
HVAC14 Lw/unit 75 - - -
HVAC15 Lw/unit 75 - - -
HVAC16 Lw/unit 75 - - -
HVAC17 Lw/unit 75 - - -
HVAC18 Lw/unit 75 - - -
HVAC19 Lw/unit 75 - - -
HVAC20 Lw/unit 75 - - -
HVAC21 Lw/unit 75 - - -
HVAC22 Lw/unit 75 - - -
HVAC23 Lw/unit 75 - - -
HVAC24 Lw/unit 75 - - -
HVAC25 Lw/unit 75 - - -
HVAC26 Lw/unit 75 - - -
HVAC27 Lw/unit 75 - - -
HVAC28 Lw/unit 75 - - -
HVAC29 Lw/unit 75 - - -
HVAC30 Lw/unit 75 - - -
HVAC31 Lw/unit 75 - - -
HVAC32 Lw/unit 75 - - -
HVAC33 Lw/unit 75 - - -
HVAC34 Lw/unit 75 - - -
HVAC35 Lw/unit 75 - - -
HVAC36 Lw/unit 75 - - -
HVAC37 Lw/unit 75 - - -
HVAC38 Lw/unit 75 - - -
HVAC39 Lw/unit 75 - - -
HVAC40 Lw/unit 75 - - -
HVAC41 Lw/unit 75 - - -
HVAC42 Lw/unit 75 - - -
HVAC43 Lw/unit 75 - - -
HVAC44 Lw/unit 75 - - -
HVAC45 Lw/unit 75 - - -
HVAC46 Lw/unit 75 - - -
HVAC47 Lw/unit 75 - - -
HVAC48 Lw/unit 75 - - -
HVAC49 Lw/unit 75 - - -
HVAC50 Lw/unit 75 - - -
HVAC51 Lw/unit 75 - - -
HVAC52 Lw/unit 75 - - -
Corrections
HVAC
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
Noise
No. X Y Height Level
m dB(A)
1 497352.13 3633214.73 107.36 43.5
2 497348.10 3633177.67 108.17 45.8
3 497339.51 3633130.66 108.80 44.9
4 497333.78 3633100.86 109.71 42.7
5 497333.96 3633075.08 110.72 40.9
6 497374.75 3633057.52 113.16 45.7
7 497418.12 3633049.90 113.11 51.0
8 497452.06 3633066.01 110.62 50.1
9 497460.05 3633103.76 108.00 50.9
10 497436.64 3633140.29 107.74 53.1
11 497418.64 3633160.98 106.35 50.9
12 497424.66 3633197.39 104.73 48.3
13 497499.27 3633166.19 105.15 39.4
14 497489.78 3633106.95 107.84 42.2
15 497481.51 3633061.26 111.14 41.8
Coordinates
(meters)
Receivers
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
Noise
Source name Level
dB(A)
1 1.Fl 43.5 0.0
HVAC1 37.0
HVAC2 33.8
HVAC3 28.3
HVAC4 17.5
HVAC5 25.0
HVAC6 28.3
HVAC7 30.7
HVAC8 33.6
HVAC9 32.2
HVAC10 29.5
HVAC11 27.6
HVAC12 24.7
HVAC13 27.1
HVAC14 26.2
HVAC15 25.1
HVAC16 23.9
HVAC17 26.2
HVAC18 25.2
HVAC19 24.5
HVAC20 23.4
HVAC21 23.3
HVAC22 22.3
HVAC23 22.1
HVAC24 21.2
HVAC25 21.1
HVAC26 20.1
HVAC27 19.1
HVAC28 19.0
HVAC29 18.4
HVAC30 18.0
HVAC31 17.2
HVAC32 17.6
HVAC33 17.7
HVAC34 18.1
HVAC35 18.2
HVAC36 18.6
HVAC37 19.1
HVAC38 19.4
HVAC39 20.0
HVAC40 19.6
HVAC41 20.4
HVAC42 20.5
HVAC43 20.9
HVAC44 20.9
HVAC45 19.4
HVAC46 20.4
HVAC47 20.5
HVAC48 21.6
HVAC49 21.7
HVAC50 22.6
HVAC51 22.7
HVAC52 22.9
2 1.Fl 45.8 0.0
HVAC1 30.1
HVAC2 29.3
HVAC3 26.5
HVAC4 16.7
HVAC5 25.6
HVAC6 29.3
HVAC7 32.4
HVAC8 37.1
HVAC9 39.2
HVAC10 32.8
HVAC11 29.7
HVAC12 25.9
HVAC13 34.8
HVAC14 31.3
HVAC15 28.8
HVAC16 26.5
HVAC17 33.2
HVAC18 30.2
HVAC19 28.2
HVAC20 26.3
HVAC21 26.0
HVAC22 24.4
HVAC23 24.2
HVAC24 22.8
HVAC25 22.7
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC26 21.3
HVAC27 20.6
HVAC28 20.6
HVAC29 20.1
HVAC30 19.7
HVAC31 18.8
HVAC32 19.5
HVAC33 19.5
HVAC34 20.2
HVAC35 20.2
HVAC36 20.9
HVAC37 21.3
HVAC38 21.7
HVAC39 22.4
HVAC40 21.9
HVAC41 22.7
HVAC42 22.8
HVAC43 23.5
HVAC44 23.4
HVAC45 22.1
HVAC46 23.4
HVAC47 23.6
HVAC48 24.9
HVAC49 25.1
HVAC50 26.3
HVAC51 26.9
HVAC52 27.4
3 1.Fl 44.9 0.0
HVAC1 23.3
HVAC2 23.2
HVAC3 22.3
HVAC4 14.5
HVAC5 23.0
HVAC6 24.9
HVAC7 25.9
HVAC8 26.8
HVAC9 27.9
HVAC10 26.9
HVAC11 25.7
HVAC12 23.7
HVAC13 33.1
HVAC14 30.2
HVAC15 28.1
HVAC16 26.1
HVAC17 35.3
HVAC18 31.2
HVAC19 28.3
HVAC20 26.7
HVAC21 26.5
HVAC22 24.6
HVAC23 24.4
HVAC24 22.9
HVAC25 22.8
HVAC26 21.4
HVAC27 21.6
HVAC28 21.6
HVAC29 21.3
HVAC30 21.2
HVAC31 20.5
HVAC32 21.5
HVAC33 21.6
HVAC34 22.7
HVAC35 22.8
HVAC36 23.9
HVAC37 23.5
HVAC38 24.3
HVAC39 24.8
HVAC40 23.9
HVAC41 24.4
HVAC42 24.5
HVAC43 25.5
HVAC44 25.4
HVAC45 25.3
HVAC46 27.9
HVAC47 28.1
HVAC48 29.3
HVAC49 29.4
HVAC50 29.6
HVAC51 34.0
HVAC52 37.3
4 1.Fl 42.7 0.0
HVAC1 20.7
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC2 20.6
HVAC3 20.1
HVAC4 13.3
HVAC5 20.9
HVAC6 22.2
HVAC7 22.8
HVAC8 23.2
HVAC9 23.9
HVAC10 23.5
HVAC11 22.9
HVAC12 21.7
HVAC13 27.2
HVAC14 26.2
HVAC15 25.1
HVAC16 24.0
HVAC17 28.5
HVAC18 27.2
HVAC19 25.6
HVAC20 24.8
HVAC21 24.7
HVAC22 23.3
HVAC23 23.1
HVAC24 21.9
HVAC25 21.8
HVAC26 20.7
HVAC27 21.3
HVAC28 21.3
HVAC29 21.4
HVAC30 21.5
HVAC31 20.9
HVAC32 21.9
HVAC33 22.0
HVAC34 23.2
HVAC35 23.3
HVAC36 24.8
HVAC37 23.9
HVAC38 24.7
HVAC39 25.0
HVAC40 24.1
HVAC41 23.9
HVAC42 23.9
HVAC43 24.8
HVAC44 24.8
HVAC45 26.8
HVAC46 28.5
HVAC47 28.5
HVAC48 29.2
HVAC49 29.1
HVAC50 27.7
HVAC51 32.0
HVAC52 34.3
5 1.Fl 40.9 0.0
HVAC1 19.0
HVAC2 19.0
HVAC3 18.7
HVAC4 12.8
HVAC5 19.6
HVAC6 20.5
HVAC7 20.8
HVAC8 21.1
HVAC9 21.7
HVAC10 21.5
HVAC11 21.1
HVAC12 20.3
HVAC13 24.2
HVAC14 23.6
HVAC15 23.1
HVAC16 22.4
HVAC17 25.1
HVAC18 24.4
HVAC19 23.5
HVAC20 23.2
HVAC21 23.1
HVAC22 22.1
HVAC23 21.9
HVAC24 21.0
HVAC25 20.9
HVAC26 19.9
HVAC27 21.0
HVAC28 21.0
HVAC29 21.2
HVAC30 21.3
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC31 21.2
HVAC32 22.4
HVAC33 22.5
HVAC34 24.0
HVAC35 24.1
HVAC36 25.0
HVAC37 23.6
HVAC38 24.4
HVAC39 24.4
HVAC40 23.5
HVAC41 23.2
HVAC42 23.1
HVAC43 23.7
HVAC44 23.8
HVAC45 27.7
HVAC46 28.2
HVAC47 28.1
HVAC48 26.9
HVAC49 26.7
HVAC50 25.3
HVAC51 28.3
HVAC52 29.2
6 1.Fl 45.7 0.0
HVAC1 18.7
HVAC2 18.8
HVAC3 18.9
HVAC4 17.0
HVAC5 20.6
HVAC6 20.8
HVAC7 20.8
HVAC8 20.6
HVAC9 21.1
HVAC10 21.4
HVAC11 21.4
HVAC12 21.2
HVAC13 23.4
HVAC14 23.8
HVAC15 23.8
HVAC16 23.6
HVAC17 24.1
HVAC18 24.7
HVAC19 24.4
HVAC20 24.8
HVAC21 24.7
HVAC22 24.0
HVAC23 23.9
HVAC24 23.3
HVAC25 23.2
HVAC26 22.3
HVAC27 24.5
HVAC28 24.6
HVAC29 25.7
HVAC30 26.3
HVAC31 26.2
HVAC32 28.1
HVAC33 28.2
HVAC34 30.9
HVAC35 31.3
HVAC36 34.4
HVAC37 30.2
HVAC38 31.6
HVAC39 30.1
HVAC40 29.1
HVAC41 27.2
HVAC42 27.0
HVAC43 27.6
HVAC44 27.9
HVAC45 38.8
HVAC46 35.1
HVAC47 34.5
HVAC48 30.5
HVAC49 30.2
HVAC50 26.3
HVAC51 28.2
HVAC52 27.4
7 1.Fl 51.0 0.0
HVAC1 18.0
HVAC2 18.2
HVAC3 18.6
HVAC4 18.5
HVAC5 20.4
HVAC6 20.3
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC7 20.0
HVAC8 19.6
HVAC9 20.0
HVAC10 20.6
HVAC11 20.9
HVAC12 20.9
HVAC13 21.8
HVAC14 22.5
HVAC15 23.0
HVAC16 22.6
HVAC17 22.2
HVAC18 23.2
HVAC19 23.5
HVAC20 24.4
HVAC21 24.5
HVAC22 24.9
HVAC23 24.9
HVAC24 24.9
HVAC25 25.0
HVAC26 24.5
HVAC27 28.3
HVAC28 28.6
HVAC29 31.5
HVAC30 33.7
HVAC31 37.0
HVAC32 43.1
HVAC33 43.6
HVAC34 43.7
HVAC35 43.2
HVAC36 36.0
HVAC37 36.2
HVAC38 35.2
HVAC39 32.3
HVAC40 32.9
HVAC41 29.5
HVAC42 29.2
HVAC43 28.9
HVAC44 29.2
HVAC45 30.7
HVAC46 29.7
HVAC47 29.5
HVAC48 27.7
HVAC49 27.5
HVAC50 24.4
HVAC51 25.2
HVAC52 24.3
8 1.Fl 50.1 0.0
HVAC1 17.9
HVAC2 18.3
HVAC3 19.0
HVAC4 18.9
HVAC5 20.6
HVAC6 20.4
HVAC7 19.9
HVAC8 19.3
HVAC9 19.6
HVAC10 20.4
HVAC11 20.9
HVAC12 21.1
HVAC13 21.0
HVAC14 21.8
HVAC15 22.5
HVAC16 22.9
HVAC17 21.2
HVAC18 22.3
HVAC19 22.6
HVAC20 24.4
HVAC21 24.6
HVAC22 25.7
HVAC23 25.7
HVAC24 26.7
HVAC25 26.8
HVAC26 27.3
HVAC27 33.0
HVAC28 33.4
HVAC29 39.1
HVAC30 44.5
HVAC31 44.8
HVAC32 38.3
HVAC33 37.5
HVAC34 32.5
HVAC35 32.1
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC36 28.9
HVAC37 32.8
HVAC38 30.9
HVAC39 30.1
HVAC40 31.8
HVAC41 29.8
HVAC42 29.5
HVAC43 28.5
HVAC44 28.7
HVAC45 26.0
HVAC46 25.8
HVAC47 25.8
HVAC48 25.2
HVAC49 25.2
HVAC50 23.5
HVAC51 23.1
HVAC52 22.3
9 1.Fl 50.9 0.0
HVAC1 19.4
HVAC2 19.9
HVAC3 21.0
HVAC4 21.0
HVAC5 23.1
HVAC6 22.4
HVAC7 21.6
HVAC8 20.7
HVAC9 20.9
HVAC10 22.0
HVAC11 22.8
HVAC12 23.7
HVAC13 21.9
HVAC14 23.1
HVAC15 24.2
HVAC16 25.7
HVAC17 22.0
HVAC18 23.3
HVAC19 24.5
HVAC20 26.9
HVAC21 27.2
HVAC22 29.6
HVAC23 29.8
HVAC24 33.2
HVAC25 33.6
HVAC26 37.4
HVAC27 46.3
HVAC28 45.8
HVAC29 38.9
HVAC30 34.7
HVAC31 28.2
HVAC32 28.4
HVAC33 28.2
HVAC34 27.0
HVAC35 26.8
HVAC36 25.4
HVAC37 29.6
HVAC38 28.3
HVAC39 29.1
HVAC40 30.7
HVAC41 31.7
HVAC42 31.8
HVAC43 30.0
HVAC44 29.9
HVAC45 23.9
HVAC46 24.6
HVAC47 24.7
HVAC48 25.0
HVAC49 25.1
HVAC50 24.6
HVAC51 23.2
HVAC52 22.2
10 1.Fl 53.1 0.0
HVAC1 23.2
HVAC2 24.1
HVAC3 26.0
HVAC4 25.8
HVAC5 30.2
HVAC6 28.7
HVAC7 27.0
HVAC8 25.2
HVAC9 25.3
HVAC10 27.6
HVAC11 29.7
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC12 30.8
HVAC13 26.3
HVAC14 28.7
HVAC15 31.5
HVAC16 36.0
HVAC17 26.1
HVAC18 28.6
HVAC19 31.6
HVAC20 35.8
HVAC21 36.5
HVAC22 44.0
HVAC23 44.9
HVAC24 47.4
HVAC25 46.6
HVAC26 38.1
HVAC27 31.3
HVAC28 30.9
HVAC29 28.2
HVAC30 26.8
HVAC31 24.2
HVAC32 24.5
HVAC33 24.5
HVAC34 24.5
HVAC35 24.5
HVAC36 24.1
HVAC37 27.1
HVAC38 26.9
HVAC39 28.4
HVAC40 28.7
HVAC41 31.9
HVAC42 32.4
HVAC43 31.8
HVAC44 31.4
HVAC45 23.8
HVAC46 25.3
HVAC47 25.4
HVAC48 27.1
HVAC49 27.3
HVAC50 27.8
HVAC51 26.1
HVAC52 24.9
11 1.Fl 50.9 0.0
HVAC1 26.0
HVAC2 27.4
HVAC3 30.1
HVAC4 29.5
HVAC5 39.9
HVAC6 36.1
HVAC7 32.2
HVAC8 29.0
HVAC9 29.1
HVAC10 33.2
HVAC11 38.4
HVAC12 45.0
HVAC13 29.1
HVAC14 32.4
HVAC15 36.5
HVAC16 41.7
HVAC17 28.3
HVAC18 31.2
HVAC19 35.0
HVAC20 37.3
HVAC21 37.4
HVAC22 36.6
HVAC23 36.3
HVAC24 33.0
HVAC25 32.6
HVAC26 29.4
HVAC27 26.0
HVAC28 25.8
HVAC29 24.4
HVAC30 23.6
HVAC31 21.8
HVAC32 22.2
HVAC33 22.2
HVAC34 22.4
HVAC35 22.4
HVAC36 22.4
HVAC37 24.5
HVAC38 24.5
HVAC39 25.9
HVAC40 25.7
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC41 27.8
HVAC42 28.2
HVAC43 28.6
HVAC44 28.3
HVAC45 23.1
HVAC46 24.8
HVAC47 25.0
HVAC48 26.9
HVAC49 27.2
HVAC50 29.1
HVAC51 26.7
HVAC52 25.6
12 1.Fl 48.3 0.0
HVAC1 28.4
HVAC2 30.2
HVAC3 37.6
HVAC4 45.4
HVAC5 37.0
HVAC6 34.0
HVAC7 30.6
HVAC8 27.9
HVAC9 27.2
HVAC10 29.6
HVAC11 32.1
HVAC12 34.4
HVAC13 25.0
HVAC14 26.3
HVAC15 27.3
HVAC16 27.9
HVAC17 24.2
HVAC18 25.3
HVAC19 26.6
HVAC20 27.1
HVAC21 27.1
HVAC22 27.0
HVAC23 26.9
HVAC24 26.4
HVAC25 26.2
HVAC26 25.2
HVAC27 22.2
HVAC28 22.1
HVAC29 21.0
HVAC30 20.3
HVAC31 19.0
HVAC32 19.2
HVAC33 19.2
HVAC34 19.4
HVAC35 19.4
HVAC36 19.4
HVAC37 20.8
HVAC38 20.8
HVAC39 21.6
HVAC40 21.6
HVAC41 23.0
HVAC42 23.2
HVAC43 23.3
HVAC44 23.2
HVAC45 20.0
HVAC46 21.2
HVAC47 21.3
HVAC48 22.5
HVAC49 22.7
HVAC50 23.6
HVAC51 22.5
HVAC52 21.9
13 1.Fl 39.4 0.0
HVAC1 19.8
HVAC2 20.7
HVAC3 22.9
HVAC4 23.1
HVAC5 23.9
HVAC6 22.7
HVAC7 21.5
HVAC8 20.3
HVAC9 20.1
HVAC10 21.5
HVAC11 22.6
HVAC12 23.6
HVAC13 19.9
HVAC14 21.0
HVAC15 22.0
HVAC16 23.0
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC17 19.7
HVAC18 20.7
HVAC19 21.7
HVAC20 23.0
HVAC21 23.2
HVAC22 24.6
HVAC23 24.7
HVAC24 26.4
HVAC25 26.5
HVAC26 28.0
HVAC27 24.7
HVAC28 24.5
HVAC29 23.0
HVAC30 22.2
HVAC31 20.1
HVAC32 20.0
HVAC33 19.9
HVAC34 19.4
HVAC35 19.4
HVAC36 18.9
HVAC37 20.6
HVAC38 20.3
HVAC39 20.8
HVAC40 21.2
HVAC41 22.2
HVAC42 22.3
HVAC43 21.8
HVAC44 21.7
HVAC45 18.4
HVAC46 19.0
HVAC47 19.1
HVAC48 19.7
HVAC49 19.8
HVAC50 20.2
HVAC51 19.1
HVAC52 18.6
14 1.Fl 42.2 0.0
HVAC1 18.4
HVAC2 19.0
HVAC3 20.4
HVAC4 20.4
HVAC5 21.9
HVAC6 21.1
HVAC7 20.0
HVAC8 19.1
HVAC9 19.1
HVAC10 20.2
HVAC11 21.0
HVAC12 22.1
HVAC13 19.8
HVAC14 20.8
HVAC15 21.7
HVAC16 23.0
HVAC17 19.8
HVAC18 20.9
HVAC19 21.9
HVAC20 23.5
HVAC21 23.8
HVAC22 25.7
HVAC23 25.7
HVAC24 28.5
HVAC25 28.8
HVAC26 32.0
HVAC27 31.9
HVAC28 31.7
HVAC29 30.0
HVAC30 28.8
HVAC31 25.1
HVAC32 24.4
HVAC33 24.3
HVAC34 23.5
HVAC35 23.4
HVAC36 22.3
HVAC37 25.1
HVAC38 24.3
HVAC39 24.7
HVAC40 25.6
HVAC41 26.0
HVAC42 26.0
HVAC43 25.1
HVAC44 25.1
HVAC45 21.2
Contributions
10174 Mission Gorge Condos
SoundPLAN Data - HVAC
HVAC46 21.7
HVAC47 21.7
HVAC48 21.9
HVAC49 21.9
HVAC50 21.7
HVAC51 20.6
HVAC52 19.8
15 1.Fl 41.8 0.0
HVAC1 16.9
HVAC2 17.3
HVAC3 18.2
HVAC4 18.2
HVAC5 19.4
HVAC6 19.2
HVAC7 18.6
HVAC8 18.0
HVAC9 18.2
HVAC10 19.0
HVAC11 19.6
HVAC12 19.7
HVAC13 19.2
HVAC14 20.0
HVAC15 20.5
HVAC16 21.1
HVAC17 19.3
HVAC18 20.3
HVAC19 20.7
HVAC20 22.2
HVAC21 22.4
HVAC22 23.5
HVAC23 23.6
HVAC24 24.9
HVAC25 25.0
HVAC26 26.1
HVAC27 29.5
HVAC28 29.6
HVAC29 31.1
HVAC30 30.3
HVAC31 30.3
HVAC32 27.9
HVAC33 27.6
HVAC34 26.2
HVAC35 26.1
HVAC36 24.3
HVAC37 26.3
HVAC38 25.5
HVAC39 25.2
HVAC40 25.9
HVAC41 25.6
HVAC42 25.6
HVAC43 24.7
HVAC44 24.8
HVAC45 22.5
HVAC46 22.4
HVAC47 22.4
HVAC48 22.1
HVAC49 22.1
HVAC50 21.1
HVAC51 20.6
HVAC52 19.9
Contributions
23811 Washington Ave, C110-333, Murrieta CA 92562 phone 760-473-1253 www.ldnconsulting.net fax 760-689-4943
12/17/24 24-43 Aubrey Glen Carwash Noise 1
December 17, 2024
Jesse Kleist
KB Home Coastal
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
SUBJECT: Operational Noise Evaluation of the adjacent Car Wash at the Aubrey Glen Residential Development – City of Santee
The firm of Ldn Consulting is pleased to submit the following noise impact analysis for the existing Car Wash adjacent to the proposed Aubrey Glen Residential Development in the City of Santee. The purpose of the survey is to determine the estimated noise levels from the existing and proposed operations of the car wash and recommend any mitigation measures, if needed, for compliance with the City of Santee Ordinance requirements for noise.

PROJECT LOCATION
The project consists of an existing car wash facility as part of an existing Shell gas station, located adjacent to the northern property line of the proposed Aubrey Glen residential development. The carwash is temporarily closed but would potentially be reopened after renovations. The existing car wash is located at 7751 Mission Gorge Road. The proposed Aubrey Glen Residential Development is located at 7737 Mission Gorge Road in the City of Santee, as can be seen in Figure 1.

PROJECT DESCRIPTION
The carwash facility was previously open Monday through Saturday, 8 am to 5 pm, and Sunday from 8 am to 4 pm. Previous and expected operations consist of stationary noise sources, including existing vacuum stations at the site that are supplied by a central vacuum system and a car wash tunnel. An existing 12-foot wall is located at the exit of the car wash and the proposed Aubrey Glen Residential Development is proposing a 6-foot perimeter wall located along the property line of the car wash. The project site configuration and noise producing equipment locations are provided in Figure 2.

Jesse Kleist
KB Home Coastal
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
23811 Washington Ave, C110-333
Murrieta CA 92562
phone 760-473-1253
12/17/24 24-43 Aubrey Glen Carwash Noise 2
Figure 1: Project Site Location
Project
Location
Jesse Kleist
KB Home Coastal
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
23811 Washington Ave, C110-333
Murrieta CA 92562
phone 760-473-1253
12/17/24 24-43 Aubrey Glen Carwash Noise 3
Figure 2: Project Site Configuration

Exit
Entrance
Vacuums
Proposed Aubrey
Glen Residential
Development
Carwash
Existing
12-Foot Wall
Proposed
6-Foot Wall
Vacuum
Equipment
Jesse Kleist
KB Home Coastal
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
23811 Washington Ave, C110-333
Murrieta CA 92562
phone 760-473-1253
12/17/24 24-43 Aubrey Glen Carwash Noise 4

NOISE STANDARDS
Impacts to sensitive receptors generated by activities at a given location are regulated by the City’s Municipal Code (Section 5.04.040). The municipal code states that” it is unlawful for any person to operate or allow the operation of any generator, air conditioning, refrigeration, or heating equipment in such manner as to create a noise disturbance on the premises of any other occupied property, or if a condominium, apartment house, duplex, or attached business, within any adjoining unit”. The municipal code does not specify numerical sound level limits for operational noise, therefore, in accordance with the Noise Element of the General Plan, the noise level threshold is 65 dBA Leq at the residential property lines. Additionally, the previous noise study by RECON Environmental used a property line threshold of 65 dBA Leq (Source:

Noise Analysis for the Aubrey Glen Project, RECON Number 10174-1).

ANALYSIS PROCEDURES
To examine the potential noise impacts associated with the operation of the proposed project, sound level measurements of the equipment were taken at a similar car wash. The noise measurements were taken at the existing Soapy Joe Car Wash in San Marcos in January 2019 using a Larson-Davis Model LxT Type 1 precision sound level meter, programmed, in "slow" mode, to record noise levels in "A" weighted form. The sound level meter was mounted on a tripod, five feet above the ground and equipped with a windscreen. The results of the noise measurements are shown in Table 1.

Table 1: Reference Noise Levels
Equipment Distance from
Source in Feet Noise Level (dBA) Quanity Cumulative Noise Level (dBA) Vacuums 5 70.2 4 76.2
Vacuum Equipment 3 81.8 1 81.8
Carwash Entrance 5 81.1 1 81.1
Carwash Exit 5 88.0 1 88.0
Jesse Kleist
KB Home Coastal
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
23811 Washington Ave, C110-333
Murrieta CA 92562
phone 760-473-1253
12/17/24 24-43 Aubrey Glen Carwash Noise 5

FINDINGS
Fixed or point sources radiate outward uniformly as sound travels away from the source.

Their sound levels attenuate or drop off at a rate of 6 dBA for each doubling of distance.

Using a point-source noise prediction model, calculations of the expected operational noise impacts were completed. The essential model input data for these performance equations include the source levels of each type of equipment, relative source to receiver horizontal and vertical separations, the amount of time the equipment is operating in a given day (also referred to as the duty-cycle) and any transmission loss from topography or barriers. It is important to note that the projected noise levels assume the worst-case noise environment with the all the noise producing equipment operating at the same time. In reality, these noise levels will vary throughout the day and not operate on a continuous basis. The anticipated hours of operation will only occur during the daytime hours as described previously.

The worst case potentially affected property lines are the residential uses to the west and to the south. The noise levels for each source, as shown in Table 1 above, are provided in Table

2. Additionally, reductions from the existing 12-foot wall at the car wash exit as well as the proposed 6-foot perimeter wall to be constructed as part of the Aubrey Glen Residential Development were factored into the resultant noise levels. The 6-foot barrier will block the line of sight to the vacuums and the carwash entrance, therefore, a minimum 5 dBA noise reduction was factored in. The Fresnel Barrier calculations have been provided as an attachment to this report.

Table 2: Operational Noise Levels
Source
Cumulative
Noise Level
(dBA)
Distance to
Property Line
(Feet)
Reduction Due
to Distance
(dBA)
Reduction Due
to Shielding
(dBA)
Cumulative
Noise Level
(dBA)
Vacuums 76.2 48 -19.6 -5.0* 51.6
Vacuum Equipment 81.8 8 -8.5 -11.6 61.7
Carwash Entrance 81.1 18 -11.1 -5.0* 65.0
Carwash Exit 88.0 18 -11.1 -18.2 58.7
*Minimum shielding due to the proposed 6-foot wall.

Jesse Kleist
KB Home Coastal
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
23811 Washington Ave, C110-333
Murrieta CA 92562
phone 760-473-1253
12/17/24 24-43 Aubrey Glen Carwash Noise 6
Based upon the property line noise levels determined, none of the proposed noise sources exceed the property line standards at the property lines. Therefore, the existing car wash operational noise levels comply with the noise standards at the property lines and no substantial permanent noise increase is anticipated. No impacts are anticipated and no mitigation is required. Additionally, it is unlikely that the equipment would be running continuously during any given hour. Therefore, noise levels are likely to be reduced below the levels shown in Table 2.

Sincerely Ldn Consulting,
Jeremy Louden, Principal
Attachment: Noise Barrier Reduction Calculations
Vacuum Equipment
Source to Receiver Horizontal Distance (ft) = 8.00
Source to Barrier Horizontal Distance (ft) = 3.00
Barrier to Receiver Horizontal Distance (ft) = 5.00
Source Height (ft) = 4.00
Receiver Height (ft) = 5.00
Barrier Height (ft) = 6.00
Distance Source to Receptor (ft) d = 8.06
Distance Source to Barrier top (ft) d1 = 3.61
Distance Barrier top to Receiver (ft) d2 = 5.10

Frequency (Hz) = 8000 Attenuation (db) = 20.0 Fresnel N = 9.119 Frequency (Hz) = 4000 Attenuation (db) = 19.5 Fresnel N = 4.559 Frequency (Hz) = 2000 Attenuation (db) = 16.5 Fresnel N = 2.280 Frequency (Hz) = 1000 Attenuation (db) = 13.8 Fresnel N = 1.140 Frequency (Hz) = 500 Attenuation (db) = 11.6 Fresnel N = 0.570 Frequency (Hz) = 250 Attenuation (db) = 9.8 Fresnel N = 0.285 Frequency (Hz) = 125 Attenuation (db) = 8.3 Fresnel N = 0.142 Frequency (Hz) = 63 Attenuation (db) = 7.1 Fresnel N = 0.071

Car Wash Exit
Source to Receiver Horizontal Distance (ft) = 23.00
Source to Barrier Horizontal Distance (ft) = 18.00
Barrier to Receiver Horizontal Distance (ft) = 5.00
Source Height (ft) = 8.00
Receiver Height (ft) = 5.00
Barrier Height (ft) = 12.00
Distance Source to Receptor (ft) d = 23.19
Distance Source to Barrier top (ft) d1 = 18.44
Distance Barrier top to Receiver (ft) d2 = 8.60

Frequency (Hz) = 8000 Attenuation (db) = 20.0 Fresnel N = 54.610 Frequency (Hz) = 4000 Attenuation (db) = 20.0 Fresnel N = 27.305 Frequency (Hz) = 2000 Attenuation (db) = 20.0 Fresnel N = 13.652 Frequency (Hz) = 1000 Attenuation (db) = 20.0 Fresnel N = 6.826 Frequency (Hz) = 500 Attenuation (db) = 18.2 Fresnel N = 3.413 Frequency (Hz) = 250 Attenuation (db) = 15.3 Fresnel N = 1.707 Frequency (Hz) = 125 Attenuation (db) = 12.9 Fresnel N = 0.853 Frequency (Hz) = 63 Attenuation (db) = 10.8 Fresnel N = 0.427

An Employee-Owned Company
3111 Camino del Rio North, Suite 600, San Diego, CA 92108-5726 | 619.308.9333 | reconenvironmental.com SAN DIEGO | OAKLAND | TUCSON
November 13, 2024
Mr. Troy Friedeck
KB Home Coastal, Inc.
9915 Mira Mesa Boulevard, Suite 100
San Diego, CA 92131
Reference: Air Quality Analysis for the Aubrey Glen Project (RECON Number 10174-1) Dear Mr. Friedeck:

The purpose of this report is to assess potential short-term local and regional air quality impacts resulting from development of the Aubrey Glen Project (project) located in the city of Santee, California. The analysis of impacts is based on state and federal Ambient Air Quality Standards (AAQS) and assessed in accordance with the regional guidelines, policies, and standards and the San Diego Air Pollution Control District (SDAPCD) and the City of Santee (City).

1.0 Project Description
The project site is located at 7737 Mission Gorge Road (Assessor’s Parcel Number 386-300-31-00) in the city of Santee, California. The project site is located east of Aubrey Glen Drive and south of Mission Gorge Road. The

USMC AIR

STATION

S A N D I E G O

C O U N T Y

USMC AIR

STATION

S A N D I E G O

C O U N T Y

ANGELES

ORANGE RIVERSIDE

SAN BERNARDINO

SAN DIEGO
MEXICO
kj Project Location
FIGURE 2
Project Location on Aerial Photograph

WEST HILLS PKY

MISSION GORGE RD

CYPRESS DR

VIA MONTISI

ARUBA LN

BU S HY HILL DR

TRINIDAD CT

CORAL RIDGE RD

VIA SOVANA

WREN ST

AUBREY GLEN

DOVE ST LA
U
REL H
EIG
H
T S
DR
BUSHY
H
LI L
DR

FATHER JUNIPERO SERRA TRL
C
A
R
R
BI E
A
N
W
AY

ROSEMOND LN

CLARE LN

DOVE ST

ROBINSON LN

HIGHRIDG
E
R
D

RANCHO FANITA DR

OLIVEH ILL R
D

S UNRIDGE
DR

WOODPECKER WAY

HISER LN

FERNRIDGE RD

STELLA CT

ORGANDY LN

CRESCENT RIDGE RD

LINEN DR

ARLY CT

WISTFUL VISTA

PINERIDG E
RD

SIMEON DR

ROLLING OAKS RD

STARPINE DR

RIDGECREST RD

BRITT PL
UV52

WEST HILLS PKY

MISSION GORGE RD

CYPRESS DR

VIA MONTISI

ARUBA LN

BU S HY HILL DR

TRINIDAD CT

CORAL RIDGE RD

VIA SOVANA

WREN ST

AUBREY GLEN

DOVE ST LA
U
REL H
EIG
H
T S
DR
BUSHY
H
LI L
DR

FATHER JUNIPERO SERRA TRL
C
A
R
R
BI E
A
N
W
AY

ROSEMOND LN

CLARE LN

DOVE ST

ROBINSON LN

HIGHRIDG
E
R
D

RANCHO FANITA DR

OLIVEH ILL R
D

S UNRIDGE
DR

WOODPECKER WAY

HISER LN

FERNRIDGE RD

STELLA CT

ORGANDY LN

CRESCENT RIDGE RD

LINEN DR

ARLY CT

WISTFUL VISTA

PINERIDG E
RD

SIMEON DR

ROLLING OAKS RD

STARPINE DR

RIDGECREST RD

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November 13, 2024
The following project conditions related to air quality would be required. These measures would be incorporated as Conditions of Approval for the entitlement of the site.

Standard Project Condition No. 1 – Air Quality:

7. The project shall comply with Chapters 9.02 and 9.04 of the City’s Municipal Code that pertain to solid waste management and demolition and construction debris recycling.

8. In conformance with SDAPCD Rule 67.0.1, Architectural Coatings, the project shall use low volatile organic compound (VOC) paints.

9. The project shall not include wood burning stoves or fireplaces.

2.0 Environmental Setting

2.1 Regulatory Setting

2.1.1 Federal Regulations
AAQS represent the maximum levels of background pollution considered safe, with an adequate margin of safety, to protect the public health and welfare. The federal Clean Air Act (CAA) was enacted in 1970 and amended in 1977 and 1990 (42 U.S. Code [U.S.C.] 7401) for the purposes of protecting and enhancing the quality of the nation’s air resources to benefit public health, welfare, and productivity. In 1971, in order to achieve the purposes of Section 109 of the CAA [42 U.S.C. 7409], the U.S. Environmental Protection Agency (U.S. EPA) developed primary and secondary National AAQS (NAAQS).

Mr. Troy Friedeck

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Six pollutants of primary concern were designated: ozone, carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), lead (Pb), particulate matter with a diameter of 10 microns and less (PM10), and particulate matter with a diameter of 2.5 microns and less (PM2.5). The primary NAAQS “in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health….” and the secondary standards “… protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air” [42 U.S.C. 7409(b)(2)]. The primary NAAQS were established, with a margin of safety, considering long-term exposure for the most sensitive groups in the general population (i.e., children, senior citizens, and people with breathing difficulties). The NAAQS are presented in Table 1 (California Air Resources Board [CARB] 2016).

If an air basin is not in either federal or state attainment for a particular pollutant, the basin is classified as non-attainment area for that pollutant. The San Diego Air Basin (SDAB) is currently classified as a federal non-attainment area for ozone.

2.1.2 State Regulations
Criteria Pollutants
The CARB has developed the California AAQS (CAAQS) and generally has set more stringent limits on the criteria pollutants than the NAAQS (see Table 1). In addition to the federal criteria pollutants, the CAAQS also specify standards for visibility-reducing particles, sulfates, hydrogen sulfide, and vinyl chloride.

Similar to the federal CAA, the state classifies either “attainment” or “non-attainment” areas for each pollutant based on the comparison of measured data with the CAAQS. The SDAB is a non-attainment area for the state ozone standards, the state PM10 standard, and the state PM2.5 standard. The California CAA, which became effective on January 1, 1989, requires all areas of the State to attain the CAAQS at the earliest practicable date. The California CAA has specific air quality management strategies that must be adopted by the agency responsible for the non-attainment area. In the case of the SDAB, the responsible agency is the SDAPCD.

Mr. Troy Friedeck

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Table 1
Ambient Air Quality Standards
Pollutant Averaging
Time
California Standards1 National Standards2
Concentration3 Method4 Primary3,5 Secondary3,6 Method7
Ozone8
1 Hour 0.09 ppm
(180 µg/m3) Ultraviolet
Photometry
– Same as
Primary
Standard
Ultraviolet
Photometry 8 Hour 0.07 ppm
(137 µg/m3)

0.070 ppm
(137 µg/m3)
Respirable
Particulate
Matter (PM10)
9 24 Hour 50 µg/m3
Gravimetric or Beta
Attenuation
150 µg/m3
Same as
Primary
Standard
Inertial Separation
and Gravimetric
Analysis
Annual
Arithmetic
Mean
20 µg/m3 –
Fine Particulate
Matter (PM2.5)
9 24 Hour No Separate State Standard 35 µg/m3
Same as
Primary
Standard Inertial Separation
and Gravimetric
Analysis Annual
Arithmetic
Mean
12 µg/m3 Gravimetric or Beta
Attenuation 12 µg/m3 15 µg/m3
Carbon
Monoxide (CO)
1 Hour 20 ppm
(23 mg/m3)
Non-dispersive
Infrared Photometry
35 ppm
(40 mg/m3) –
Non-dispersive
Infrared Photometry 8 Hour 9.0 ppm
(10 mg/m3)
9 ppm
(10 mg/m3) –
8 Hour
(Lake Tahoe)
6 ppm
(7 mg/m3) – –
Nitrogen
Dioxide (NO2)
10 1 Hour 0.18 ppm
(339 µg/m3) Gas Phase Chemiluminescence
100 ppb
(188 µg/m3) –
Gas Phase Chemiluminescence Annual
Arithmetic
Mean

0.030 ppm
(57 µg/m3
)

0.053 ppm
(100 µg/m3)
Same as
Primary
Standard
Sulfur Dioxide
(SO2)
11 1 Hour 0.25 ppm
(655 µg/m3)
Ultraviolet
Fluorescence
75 ppb
(196 µg/m3) –
Ultraviolet
Fluorescence;
Spectrophotometry
(Pararosaniline
Method)
3 Hour – – 0.5 ppm
(1,300 µg/m3)
24 Hour 0.04 ppm
(105 µg/m3)

0.14 ppm
(for certain areas)11 –
Annual
Arithmetic
Mean
– 0.030 ppm
(for certain areas)11 –
Lead12,13
30 Day
Average 1.5 µg/m3
Atomic Absorption
– –
High Volume
Sampler and Atomic
Absorption
Calendar
Quarter – 1.5 µg/m3 (for certain areas)12 Same as
Primary
Standard
Rolling
3-Month
Average
– 0.15 µg/m3
Visibility
Reducing
Particles14
8 Hour See footnote 14
Beta Attenuation
and Transmittance
through Filter Tape
No National Standards Sulfates 24 Hour 25 µg/m3 Ion Chromatography Hydrogen
Sulfide 1 Hour 0.03 ppm(42 µg/m3)
Ultraviolet
Fluorescence
Vinyl Chloride12 24 Hour 0.01 ppm
(26 µg/m3)
Gas Chromatography
Mr. Troy Friedeck

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November 13, 2024
Table 1
Ambient Air Quality Standards
NOTES:
ppm = parts per million; ppb = parts per billion; µg/m3 = micrograms per cubic meter; – = not applicable. 1 California standards for ozone, carbon monoxide (except 8-hour Lake Tahoe), sulfur dioxide (1 and 24 hour), nitrogen dioxide, particulate matter (PM10, PM2.5, and visibility reducing particles), are values that are not to be exceeded. All others are not to be equaled or exceeded. California ambient air quality standards are listed in the Table of Standards in Section 70200 of Title 17 of the California Code of Regulations. 2 National standards (other than ozone, particulate matter, and those based on annual arithmetic mean) are not to be exceeded more than once a year. The ozone standard is attained when the fourth highest 8-hour concentration measured at each site in a year, averaged over three years, is equal to or less than the standard. For PM10, the 24-hour standard is attained when the expected number of days per calendar year with a 24-hour average concentration above 150 µg/m3 is equal to or less than one. For PM2.5, the 24-hour standard is attained when 98 percent of the daily concentrations, averaged over three years, are equal to or less than the standard.

Contact the U.S. EPA for further clarification and current national policies. 3 Concentration expressed first in units in which it was promulgated. Equivalent units given in parentheses are based upon a reference temperature of 25°C and a reference pressure of 760 torr. Most measurements of air quality are to be corrected to a reference temperature of 25°C and a reference pressure of 760 torr; ppm in this table refers to ppm by volume, or micromoles of pollutant per mole of gas. 4 Any equivalent measurement method which can be shown to the satisfaction of the Air Resources Board to give equivalent results at or near the level of the air quality standard may be used. 5 National Primary Standards: The levels of air quality necessary, with an adequate margin of safety to protect the public health. 6 National Secondary Standards: The levels of air quality necessary to protect the public welfare from any known or anticipated adverse effects of a pollutant. 7 Reference method as described by the U.S. EPA. An “equivalent method” of measurement may be used but must have a “consistent relationship to the reference method” and must be approved by the U.S. EPA. 8 On October 1, 2015, the national 8-hour ozone primary and secondary standards were lowered from 0.075 to 0.070 ppm. 9 On December 14, 2012, the national annual PM2.5 primary standard was lowered from 15 µg/m3 to 12.0 µg/m3 . The existing national 24-
hour PM2.5 standards (primary and secondary) were retained at 35 µg/m3 , as was the annual secondary standards of 15 µg/m3. The existing 24-hour PM10 standards (primary and secondary) of 150 µg/m3 also were retained. The form of the annual primary and secondary standards is the annual mean, averaged over 3 years. 10 To attain the 1-hour national standard, the 3-year average of the annual 98th percentile of the 1-hour daily maximum concentrations at each site must not exceed 100 ppb. Note that the national standards are in units of parts per billion (ppb). California standards are in units of parts per million (ppm). To directly compare the national standards to the California standards the units can be converted from ppb to ppm. In this case, the national standard of 100 ppb is identical to 0.100 ppm. 11 On June 2, 2010, a new 1-hour SO2 standard was established and the existing 24-hour and annual primary standards were revoked. To attain the 1-hour national standard, the 3-year average of the annual 99th percentile of the 1-hour daily maximum concentrations at each site must not exceed 75 ppb. The 1971 SO2 national standards (24-hour and annual) remain in effect until one year after an area is designated for the 2010 standard, except that in areas designated nonattainment for the 1971 standards, the 1971 standards remain in effect until implementation plans to attain or maintain the 2010 standards are approved.

Note that the 1-hour national standard is in units of parts per billion (ppb). California standards are in units of parts per million (ppm). To directly compare the 1-hour national standard to the California standard the units can be converted to ppm. In this case, the national standard of 75 ppb is identical to 0.075 ppm. 12 The CARB has identified lead and vinyl chloride as ‘toxic air contaminants’ with no threshold level of exposure for adverse health effects determined. These actions allow for the implementation of control measures at levels below the ambient concentrations specified for these pollutants. 13 The national standard for lead was revised on October 15, 2008 to a rolling 3-month average. The 1978 lead standard (1.5 μg/m3 as a quarterly average) remains in effect until one year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978 standard, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are approved. 14 In 1989, the CARB converted both the general statewide 10-mile visibility standard and the Lake Tahoe 30-mile visibility standard to instrumental equivalents, which are “extinction of 0.23 per kilometer” and “extinction of 0.07 per kilometer” for the statewide and Lake Tahoe Air Basin standards, respectively.

SOURCE: CARB 2016.

Mr. Troy Friedeck

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Toxic Air Contaminants
The public’s exposure to toxic air contaminants (TACs) is a significant public health issue in California. Diesel particulate matter (DPM) emissions have been identified as TACs. In 1983, the California Legislature enacted a program to identify the health effects of TACs and to reduce exposure to these contaminants to protect the public health (Assembly Bill [AB] 1807: Health and Safety Code Sections 39650–39674). The California Legislature established a two-step process to address the potential health effects from TACs. The first step is the risk assessment (or identification) phase. The second step is the risk management (or control) phase of the process.

The goals of the Air Toxics “Hot Spots” Act are to collect emission data, to identify facilities having localized impacts, to ascertain health risks, to notify nearby residents of significant risks, and to reduce those significant risks to acceptable levels.

The Children’s Environmental Health Protection Act, California Senate Bill 25 (Chapter 731, Escutia, Statutes of 1999), focuses on children’s exposure to air pollutants. The act requires CARB to review its air quality standards from a children’s health perspective, evaluate the statewide air monitoring network, and develop any additional air toxic control measures needed to protect children’s health. Locally, toxic air pollutants are regulated through the SDAPCD Regulation XII. Of particular concern statewide are DPM emissions. DPM was established as a TAC in 1998, and is estimated to represent a majority of the cancer risk from TACs statewide (based on the statewide average). Diesel exhaust is a complex mixture of gases, vapors, and fine particles. This complexity makes the evaluation of health effects of diesel exhaust a complex scientific issue. Some of the chemicals in diesel exhaust, such as benzene and formaldehyde, have been previously identified as TACs by the CARB and are listed as carcinogens either under the state's Proposition 65 or under the federal Hazardous Air Pollutants program.

The California Air Toxics Program establishes the process for the identification and control of TACs and includes provisions to make the public aware of significant toxic exposures and for reducing risk. Additionally, the Air Toxics “Hot Spots” Information and Assessment Act (AB 2588, 1987, Connelly Bill) was enacted in 1987 and requires stationary sources to report the types and quantities of certain substances routinely released into the air.

Following the identification of DPM as a TAC in 1998, CARB has worked on developing strategies and regulations aimed at reducing the risk from DPM. The overall strategy for achieving these reductions is found in the Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-Fueled Engines and Vehicles (CARB 2000). A stated goal of the plan is to reduce the statewide cancer risk arising from exposure to DPM by 85 percent by 2020.

In April 2005, CARB published the Air Quality and Land Use Handbook: A Community Health Perspective (CARB 2005).

The handbook makes recommendations directed at protecting sensitive land uses from air pollutant emissions while balancing a myriad of other land use issues (e.g., housing, transportation needs, economics, etc.). Sensitive land uses include but are not limited to, schools, hospitals, residences, resident care facilities, and day-care centers. The handbook is not regulatory or binding on local agencies and recognizes that application takes a qualitative approach.

Therefore, the CARB has provided guidelines for the siting of land uses near heavily traveled roadways. Of pertinence to this study, the CARB guidelines indicate that siting new sensitive land uses within 500 feet of a freeway or urban roads with 100,000 or more vehicles/day should be avoided when possible.

As an ongoing process, CARB will continue to establish new programs and regulations for the control of DPM and other air-toxics emissions as appropriate. The continued development and implementation of these programs and policies will ensure that the public’s exposure to DPM and other TACs will continue to decline.

Mr. Troy Friedeck

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State Implementation Plan
The State Implementation Plan (SIP) is a collection of documents that set forth the state’s strategies for achieving the NAAQS. In California, the SIP is a compilation of new and previously submitted plans, programs (such as air quality management plans, monitoring, modeling, permitting, etc.), district rules, state regulations, and federal controls. The CARB is the lead agency for all purposes related to the SIP under state law. Local air districts and other agencies, such as the Department of Pesticide Regulation and the Bureau of Automotive Repair, prepare SIP elements and submit them to CARB for review and approval. The CARB then forwards SIP revisions to the U.S. EPA for approval and publication in the Federal Register. All of the items included in the California SIP are listed in the Code of Federal Regulations (CFR) at 40 CFR 52.220.

The SDAPCD is responsible for preparing and implementing the portion of the SIP applicable to the SDAB. The SIP plans for San Diego County specifically include the Redesignation Request and Maintenance Plan for the 1997 National Ozone Standard for San Diego County (2012), and the 2004 Revision to the California State Implementation Plan for Carbon Monoxide–Updated Maintenance Plan for Ten Federal Planning Areas.

California Environmental Quality Act
Section 15125(d) of the California Environmental Quality Act (CEQA) Guidelines requires discussion of any inconsistencies between the project and applicable general plans and regional plans, including the applicable air quality attainment or maintenance plan (or SIP).

2.1.3 Regional Air Quality Strategy
The SDAPCD prepared the original 1991/1992 Regional Air Quality Strategy (RAQS) in response to requirements set forth in the California CAA. The California CAA requires areas that are designated state non-attainment areas for ozone, CO, SO2, and NO2 prepare and implement plans to attain the standards by the earliest practicable date. The California CAA does not provide guidance on timing or requirements for attaining the state PM10 and PM2.5 standards. Attached as part of the RAQS are the Transportation Control Measures (TCMs) adopted by the San Diego Association of Governments (SANDAG). Updates of the RAQS and corresponding TCM are required every three years.

The RAQS and TCM set forth the steps needed to accomplish attainment of NAAQS and CAAQS. The most recent 2022 RAQS and TCM was adopted in 2023.

2.2 Existing Air Quality
The project is located in San Diego County, within the SDAB and approximately 15 miles east of the Pacific Ocean.

The SDAB is currently classified as a federal non-attainment area for ozone, and a state non-attainment area for ozone, PM10, and PM2.5. The eastern portion of the SDAB is surrounded by mountains to the north, east, and south.

These mountains tend to restrict airflow and concentrate pollutants in the valleys and low-lying areas.

2.2.1 Climate and Meteorology
The project area, like the rest of San Diego County, has a Mediterranean climate characterized by warm, dry summers and mild winters. The mean annual temperature for the project area is 65 degrees Fahrenheit (°F). The average annual precipitation is 12 inches, falling primarily from November to April. Winter low temperatures in the project area average about 43°F, and summer high temperatures average about 86°F. The average relative humidity is 69 percent and is based on the yearly average humidity at Lindbergh Field (Western Regional Climate Center 2022).

The dominant meteorological feature affecting the region is the Pacific High Pressure Zone, which produces the prevailing westerly to northwesterly winds. These winds tend to blow pollutants away from the coast toward the Mr. Troy Friedeck

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inland areas. Consequently, air quality near the coast is generally better than that which occurs at the base of the coastal mountain range.

Fluctuations in the strength and pattern of winds from the Pacific High Pressure Zone creates a temperature inversion layer (a layer in the atmosphere in which temperature increases with height) that acts as a lid to the vertical dispersion of air pollutants in the SDAB. Beneath the inversion layer pollutants become “trapped” as their ability to disperse diminishes. Sunlight reacts with air pollutants (reactive organic gas [ROG] and oxides of nitrogen [NOX]) to create ozone (O3). Thus, poorly dispersed pollutants along with strong sunlight results in the creation of ozone at this surface layer.

The prevailing wind pattern in the western portion of the SDAB includes a daytime onshore flow (i.e., sea breeze) and nighttime offshore flow (i.e., land breeze), which leads to pollutants being blown out to sea at night and returning to land the following day. The prevailing westerly wind pattern is sometimes interrupted by regional “Santa Ana” conditions. A Santa Ana occurs when a strong high pressure develops over the NevadaUtah area and overcomes the prevailing westerly coastal winds, sending strong, steady, hot, dry northeasterly winds over the mountains and out to sea.

Strong Santa Ana winds tend to blow pollutants out over the ocean, producing clear days. However, at the onset or during breakdown of these conditions, or if the Santa Ana is weak, local air quality may be adversely affected. In these cases, emissions from the South Coast Air Basin to the north are blown out over the ocean, and low pressure over Baja California, Mexico, draws this pollutant-laden air mass southward. As the high pressure weakens, prevailing northwesterly winds reassert themselves and send this cloud of contamination ashore in the SDAB. When this event does occur, the combination of transported and locally produced contaminants results in air quality conditions worse than normal.

2.2.2 Background Air Quality
Air quality at a particular location is a function of the kinds, amounts, and dispersal rates of pollutants being emitted into the air locally and throughout the basin. The major factors affecting pollutant dispersion are wind speed and direction, the vertical dispersion of pollutants (which is affected by inversions), and the local topography.

Air quality is commonly expressed as the number of days in which air pollution levels exceed state standards set by the CARB or federal standards set by the U.S. EPA. The SDAPCD maintains 11 air quality monitoring stations located throughout the greater San Diego metropolitan region. Air pollutant concentrations and meteorological information are continuously recorded at these stations. Measurements are then used by scientists to help forecast daily air pollution levels.

The San Diego – Kearny Villa Road monitoring station located at 6125 Kearny Villa Road, approximately 5.6 miles west of the project site, is the closest station to the project site. The second closest station with measurement data is the El Cajon – Lexington Elementary School monitoring station located at 533 South First Street, approximately 6 miles southeast of the project site. Both monitoring stations measure ozone, NOX, PM10 and PM2.5. Table 2 provides a summary of the measurements collected at the San Diego – Kearny Villa Road and El Cajon – Lexington Elementary School monitoring stations for the years 2018 through 2022.

Mr. Troy Friedeck

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Table 2
Summary of Air Quality Measurements Recorded at the
El Cajon-Lexington Elementary School and San Diego – Kearny Villa Road Air Quality Monitoring Stations Pollutant/Standard 2018 2019 2020 2021 2022
El Cajon – Lexington Elementary School
Ozone
Federal Max 8-hr (ppm) 0.079 0.074 0.083 0.076 0.088
Days 2015 Federal 8-hour Standard Exceeded (0.07 ppm) 2 2 14 3 2 Days 2008 Federal 8-hour Standard Exceeded (0.075 ppm) 2 0 5 2 1 State Max 8-hr (ppm) 0.079 0.075 0.083 0.077 0.088
Days State 8-hour Standard Exceeded (0.07 ppm) 2 2 14 3 2 Max. 1-hr (ppm) 0.087 0.094 0.094 0.088 0.100
Days State 1-hour Standard Exceeded (0.09 ppm) 0 0 0 0 1 Nitrogen Dioxide
Max 1-hr (ppm) 0.045 0.039 0.044 0.038 0.0365
Days State 1-hour Standard Exceeded (0.18 ppm) 0 0 0 0 0 Days Federal 1-hour Standard Exceeded (0.100 ppm) 0 0 0 0 0 Annual Average (ppm) 0.008 0.008 0.008 0.006 0.008
PM10*
Federal Max. Daily (µg/m3) 43.0 38.7 -- -- --
Measured Days Federal 24-hour Standard Exceeded (150 µg/m3) 0 0 0 -- -- Calculated Days Federal 24-hour Standard Exceeded (150 µg/m3) 0.0 0.0 -- -- -- Federal Annual Average (µg/m3) 22.6 20.1 -- -- --
State Max. Daily (µg/m3) 44.7 37.4 -- -- --
Measured Days State 24-hour Standard Exceeded (50 µg/m3) 0 0 0 -- -- Calculated Days State 24-hour Standard Exceeded (50 µg/m3) 0.0 -- -- -- -- State Annual Average (µg/m3) 23.0 -- -- -- --
PM2.5*
Federal Max. Daily (µg/m3) 36.2 23.8 38.2 30.2 26.4
Measured Days Federal 24-hour Standard Exceeded (35 µg/m3) 1 0 2 0 0 Calculated Days Federal 24-hour Standard Exceeded (35 µg/m3) 1.0 0.0 2.2 0.0 0.0 Federal Annual Average (µg/m3) 9.6 8.5 10.3 9.7 8.9
State Max. Daily (µg/m3) 42.0 25.7 41.6 31.5 27.3
State Annual Average (µg/m3) 10.5 -- 11.6 10.4 --
San Diego – Kearny Villa Road
Ozone
Federal Max 8-hr (ppm) 0.077 0.075 0.102 0.071 0.083
Days 2015 Federal 8-hour Standard Exceeded (0.07 ppm) 5 1 10 1 2 Days 2008 Federal 8-hour Standard Exceeded (0.075 ppm) 1 0 6 0 1 State Max 8-hr (ppm) 0.077 0.076 0.102 0.072 0.083
Days State 8-hour Standard Exceeded (0.07 ppm) 5 1 12 2 2 Max. 1-hr (ppm) 0.102 0.083 0.123 0.095 0.095
Days State 1-hour Standard Exceeded (0.09 ppm) 1 0 2 1 1 Nitrogen Dioxide
Max 1-hr (ppm) 0.045 0.046 0.052 0.060 0.0512
Days State 1-hour Standard Exceeded (0.18 ppm) 0 0 0 0 0 Days Federal 1-hour Standard Exceeded (0.100 ppm) 0 0 0 0 0 Annual Average (ppm) 0.008 0.008 0.007 0.007 0.008
Mr. Troy Friedeck

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November 13, 2024
Table 2
Summary of Air Quality Measurements Recorded at the
El Cajon-Lexington Elementary School and San Diego – Kearny Villa Road Air Quality Monitoring Stations Pollutant/Standard 2018 2019 2020 2021 2022
PM10*
Federal Max. Daily (µg/m3) 38.0 -- -- -- --
Measured Days Federal 24-hour Standard Exceeded (150 µg/m3) 0 0 0 -- -- Calculated Days Federal 24-hour Standard Exceeded (150 µg/m3) 0.0 -- -- -- -- Federal Annual Average (µg/m3) 18.4 -- -- -- --
State Max. Daily (µg/m3) 38.0 -- -- -- --
Measured Days State 24-hour Standard Exceeded (50 µg/m3) 0 0 0 -- -- Calculated Days State 24-hour Standard Exceeded (50 µg/m3) 0.0 -- -- -- -- State Annual Average (µg/m3) 18.4 -- -- -- --
PM2.5*
Federal Max. Daily (µg/m3) 32.2 16.2 47.5 20.9 13.9
Measured Days Federal 24-hour Standard Exceeded (35 µg/m3) 0 0 2 0 0 Calculated Days Federal 24-hour Standard Exceeded (35 µg/m3) 0.0 0.0 5.8 0.0 0.0 Federal Annual Average (µg/m3) 8.3 7.0 8.7 7.6 6.8
State Max. Daily (µg/m3) 32.2 15.0 -- -- --
State Annual Average (µg/m3) 8.3 -- -- -- --
SOURCE: CARB 2024.
ppm = parts per million; µg/m3 = micrograms per cubic meter; -- = Not available. * Calculated days value. Calculated days are the estimated number of days that a measurement would have been greater than the level of the standard had measurements been collected every day. The number of days above the standard is not necessarily the number of violations of the standard for the year.

3.0 Thresholds of Significance
Thresholds used to evaluate potential impacts to air quality are based on applicable criteria in the CEQA Guidelines Appendix G. The project would have a significant air quality impact if it would:

1. Obstruct or conflict with the implementation of the RAQS.

2. Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard.

3. Expose sensitive receptors to substantial pollutant concentrations.

4. Result in other emissions such as those leading to odors adversely affecting a substantial number of people.

The City has not adopted air quality significance thresholds. The SDAPCD also does not provide specific numeric thresholds for determining the significance of air quality impacts under CEQA. However, the SDAPCD does specify Air Quality Impact Analysis trigger levels for new or modified stationary sources (SDAPCD Rules 20.1, 20.2, and 20.3). The SDAPCD does not consider these trigger levels to represent adverse air quality impacts; rather, if these trigger levels are exceeded by a project, the SDAPCD requires an air quality analysis to determine if a significant air quality impact would occur. While these trigger levels do not generally apply to mobile sources or general land development projects, for comparative purposes these levels are used to evaluate the increased emissions that would be discharged to the SDAB if the project were approved. The air quality impact screening levels used in this analysis are shown in Table 3.

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Table 3
Air Quality Impact Screening Levels
Pollutant
Emission Rate
Pounds/Hour Pounds/Day Tons/Year
NOX 25 250 40
SOX 25 250 40
CO 100 550 100
PM10 -- 100 15
Lead -- 3.2 0.6
VOC, ROG1 -- 250 --
PM2.5 -- 67 10
SOURCE: SDAPCD, Rules 20.1, 20.2, 20.3. 1
ROG threshold based on federal General Conformity de minimus levels for ozone precursors.

4.0 Emission Calculations
Air emissions were calculated using California Emissions Estimator Model (CalEEMod) 2022.1 (California Air Pollution Control Officers Association 2022). CalEEMod is a tool used to estimate air emissions resulting from land development projects in the state of California. The model generates air quality emission estimates from construction activities and breaks down operational criteria pollutant emissions into three categories: mobile sources (e.g., traffic), area sources (e.g., landscaping equipment, consumer projects, and architectural coatings), and energy sources (e.g., natural gas heating). CalEEMod provides emission estimates of NOX, CO, SOX, PM10, PM2.5, and ROG.

Inputs to CalEEMod include such items as the air basin containing the project, land uses, trip generation rates, trip lengths, as well as other parameters. The complete CalEEMod model outputs are included in Attachment 1.

4.1 Construction Emissions
Construction-related activities are temporary, short-term sources of air emissions. Sources of construction-related air emissions include the following:
• Fugitive dust from grading activities;
• Construction equipment exhaust;
• Construction-related trips by workers, delivery trucks, and material-hauling trucks; and • Construction-related power consumption.

Construction-related pollutants result from dust raised during demolition and grading, emissions from construction vehicles, and chemicals used during construction. Fugitive dust emissions vary greatly during construction and are dependent on the amount and type of activity, silt content of the soil, and the weather. Vehicles moving over paved and unpaved surfaces, demolition, excavation, earth movement, grading, and wind erosion from exposed surfaces are all sources of fugitive dust. Construction operations are subject to the requirements established in Regulation 4, Rules 52, 54, and 55, of the SDAPCD’s rules and regulations.

Heavy-duty construction equipment is usually diesel powered. In general, emissions from diesel-powered equipment contain more NOX, SOX, and particulate matter than gasoline-powered engines. However, diesel-powered engines generally produce less CO and less ROG than do gasoline-powered engines. Standard construction equipment Mr. Troy Friedeck

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includes tractors/loaders/backhoes, rubber-tired dozers, excavators, graders, cranes, forklifts, rollers, paving equipment, generator sets, welders, cement and mortar mixers, and air compressors. Due to the small size of the project site, only a minimal amount of heavy construction equipment would be used. However, as a conservative analysis, default CalEEMod construction equipment types and amounts were modeled.

Primary inputs are the numbers of each piece of equipment and the length of each construction stage. Specific construction phasing and equipment parameters are not available at this time. However, CalEEMod can estimate the required construction equipment when project-specific information is unavailable. The estimates are based on surveys, performed by the South Coast Air Quality Management District and the Sacramento Metropolitan Air Quality Management District, of typical construction projects which provide a basis for scaling equipment needs and schedule with a project’s size. Air emission estimates in CalEEMod are based on the duration of construction phases; construction equipment type, quantity, and usage; grading area; season; and ambient temperature, among other parameters. Construction emissions were modeled assuming construction would begin in January 2025 and last for approximately 14 months. Assuming construction would begin in January 2025 is conservative, as continued implementation of regulations for off-road equipment, the primary construction emission source, would reduce emissions from these sources over time. Construction emissions were modeled using CalEEMod default equipment and phase duration. Table 4 summarizes the modeled construction parameters.

Table 4
Construction Parameters
Construction Phase
Phase Duration
(Days) Equipment Amount Hours per Day
Demolition 20
Concrete/Industrial Saw 1 8
Excavators 3 8
Rubber Tired Dozers 2 8
Site Preparation 5 Rubber Tired Dozers 3 8
Tractors/Loaders/Backhoes 4 8
Grading 8
Excavator 1 8
Grader 1 8
Rubber Tired Dozer 1 8
Tractors/Loaders/Backhoes 3 8
Building Construction 230
Crane 1 7
Forklifts 3 8
Generator Set 1 8
Tractors/Loaders/Backhoes 3 7
Welder 1 8
Paving 18
Cement and Mortar Mixers 2 6
Paver 1 8
Paving Equipment 2 6
Rollers 2 6
Tractor/Loader/Backhoe 1 8
Architectural Coatings 18 Air Compressor 1 6
SOURCE: California Emissions Estimator Model version 2022.1, Attachment 1.

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Table 5 shows the total projected construction maximum daily emission levels for each criteria pollutant. The CalEEMod output files for construction emissions are contained in Attachment 1.

Table 5
Summary of Worst-case Construction Emissions
(pounds per day)
Construction
Pollutant
ROG NOX CO SOX PM10 PM2.5
Demolition 2 23 21 <1 2 1
Site Preparation 3 32 31 <1 9 5
Grading 2 16 19 <1 4 2
Building Construction 1 11 15 <1 1 <1
Paving 1 6 10 <1 <1 <1
Architectural Coatings 35 1 1 <1 <1 <1
Maximum Daily Emissions 35 32 31 <1 9 5
Significance Threshold 250 250 550 250 100 67
For assessing the significance of the air quality emissions resulting during construction of the project, the construction emissions were compared to the screening thresholds. As shown in Table 5, maximum daily construction emissions associated with the project are projected to be less than the applicable thresholds for all criteria pollutants. These thresholds are designed to provide limits below which project emissions would not significantly change regional air quality. In addition, the project would be subject to Standard Project Condition No. 1 – Air Quality, items 1 through 3, 7, and 8 (refer to Section 1.0). The project applicant would implement standard construction measures compliant with mandatory SDAPCD rules and regulations (Rules 50, 51, 52, 54, and 55) for controlling emissions from fugitive dust and fumes:
• Water the grading areas a minimum of twice daily to minimize fugitive dust. • Provide sufficient erosion control to prevent washout of silty material onto public roads. • Cover haul trucks or maintain at least 12 inches of freeboard to reduce blow-off during hauling. • Periodically sweep up dirt and debris spilled onto paved surfaces to reduce resuspension of particulate matter caused by vehicle movement. Clean approach routes to construction sites of construction-related dirt.

Further, all construction equipment is subject to the CARB In-Use Off-Road Diesel-Fueled Fleets Regulation. This regulation, which applies to all off-road diesel vehicles 25 horsepower or greater, limits unnecessary idling to five minutes, requires all construction fleets to be labeled and report to CARB, bans Tier 0 equipment and phases out Tier 1 and 2 equipment (thereby replacing fleets with cleaner equipment), and requires that fleets comply with Best Available Control Technology (BACT) requirements.

Because it would not exceed the applicable thresholds for all criteria pollutants and would implement standard construction measures compliant with mandatory SDAPCD rules and regulations and CARB’s In-Use Off-Road Diesel-Fueled Fleets Regulation, project construction emissions would not result in regional emissions that would exceed the NAAQS or CAAQS or contribute to existing violations. Therefore, project construction would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment, and impacts would be less than significant.

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4.2 Operational Emissions

4.2.1 Mobile Emissions
Mobile emissions are calculated based on the vehicle type and the trip rate. Mobile-source emissions were modeled using the default CalEEMod trip generation rates which are based on the Institute of Transportation (ITE) Trip Generation Manual, 11th Edition. Based on the ITE Trip Generation Manual, 11th Edition, the project would generate

7.20 weekday trips per unit for a total of 374 daily weekday trips (Linscott, Law & Greenspan, Engineers 2024).

Weekend trip generation rates were calculated by proportionately adjusting the default CalEEMod trip rates.

CalEEMod default trip lengths and vehicle emission factors based on CARB’s 2021 Emissions Factor model were modeled for the soonest operational year of 2026.

4.2.2 Area Source Emissions
Area source emissions associated with the project include consumer products, architectural coatings, and landscaping equipment. Consumer products are chemically formulated products used by household and institutional consumers, including but not limited to detergents, cleaning compounds, polishes, floor finishes, disinfectants, sanitizers, and aerosol paints but do not include other paint products, furniture coatings, or architectural coatings.

For architectural coatings, emissions result from evaporation of solvents contained in surface coatings such as in paints and primers. Emission estimates are based on the building square footage and parking lot surface area, architectural coating emission factors, and a reapplication rate of 10 percent of area per year. Architectural coatings would comply with SDAPCD Rule 67.0.1, which limits the VOC content of paints sold within the county.

Landscaping maintenance includes fuel combustion emission from equipment such as lawn mowers, rototillers, shredders/grinders, blowers, trimmers, chain saws, and hedge trimmers as well as air compressors, generators, and pumps. Emission calculations take into account building area, equipment emission factors, and the number of operational days (summer days).

4.2.3 Energy Source Emissions
Energy source emissions associated with the project include natural gas used in space and water heating.

Combustion of any type of fuel, including natural gas, emits criteria pollutants directly into the atmosphere. When this occurs within buildings, it is considered a direct emission source associated with that building. CalEEMod uses the California Commercial End Use Survey (CEUS) database to develop energy intensity values (electricity and natural gas usage per square foot per year) for non-residential buildings. Energy source emissions were modeled using CalEEMod default values.

4.2.4 Total Operational Emissions
Using the parameters discussed above, operational project emissions were calculated. Daily operational emissions are summarized in Table 6. The CalEEMod output files are contained in Attachment 1.

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Table 6
Summary of Project Operational Emissions
(pounds per day)
Pollutant
ROG NOX CO SOX PM10 PM2.5
Mobile Sources 2 1 12 <1 3 1
Area Sources 3 <1 3 <1 <1 <1
Energy Sources <1 <1 <1 <1 <1 <1
Total 5 2 15 <1 3 1
Significance Threshold 250 250 550 250 100 67
As shown in Table 6, maximum daily operational emissions associated with the project are projected to be less than the applicable thresholds for all criteria pollutants. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, items 4 through 9 (refer to Section 1.1). Therefore, operational emissions would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment, impacts would be less than significant.

5.0 Air Quality Impact Analysis

1. Would the project conflict with or obstruct the implementation of the RAQS and/or applicable portions of the SIP? Project consistency is based on whether the project would conflict with or obstruct implementation of the RAQS and/or applicable portions of the SIP, which would lead to increases in the frequency or severity of existing air quality violations.

The RAQS is the applicable regional air quality plan that sets forth the SDAPCD’s strategies for achieving the NAAQS and CAAQS. The SDAB is designated a non-attainment area for the federal and state ozone standard. Accordingly, the RAQS was developed to identify feasible emission control measures and provide expeditious progress toward attaining the standards for ozone. The two pollutants addressed in the RAQS are ROG and NOX, which are precursors to the formation of ozone. Projected increases in motor vehicle usage, population, and growth create challenges in controlling emissions and, by extension, to maintaining and improving air quality. The most recent 2022 RAQS and TCM was adopted in 2023. (SDAPCD 2022).

The growth projections used by the SDAPCD to develop the RAQS emissions budgets are based on the population, vehicle trends, and land use plans developed in general plans and used by SANDAG in the development of the regional transportation plans and sustainable communities strategy. As such, projects that propose development that is consistent with the growth anticipated by SANDAG’s growth projections and/or the General Plan would not conflict with the RAQS. In the event that a project would propose development that is less dense than anticipated by the growth projections, the project would likewise be consistent with the RAQS. In the event a project proposes development that is greater than anticipated in the growth projections, further analysis would be warranted to determine if the project would exceed the growth projections used in the RAQS for the specific subregional area.

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of 0.2 for commercial development in the City, the 3.34-acre site could have been developed with approximately 29,000 square feet of commercial uses. The SANDAG trip generation rate for a neighborhood shopping center use is 120 trips per 1,000 square feet and the SANDAG trip generation rate for a standard commercial office is 20 trips per 1,000 square feet (SANDAG 2002). Using these rates, a hypothetical retail project would have generated 3,480 daily trips and a hypothetical office project would have generated 580 daily trips. As discussed in Section 4.2.1 above, the project would generate 236 daily trips, which would be less than the trips generated by the hypothetical retail and office projects described above. Therefore, the project would generate fewer emissions than what is accounted for in the RAQS and would not exceed the growth assumptions used in the RAQS. Furthermore, as shown in Table 6 above, project emissions would not exceed the applicable significance thresholds for any criteria pollutants. Therefore, the project would not obstruct or conflict with implementation of the RAQS, and impacts would be less than significant.

2. Would the project result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard (PM10, PM2.5, or exceed quantitative thresholds for ozone precursors: NOx and ROG)? The region is classified as an attainment area for all criterion pollutants except ozone, PM10, and PM2.5. The SDAB is a non-attainment area for the 8-hour federal and state ozone standards. Ozone is not emitted directly but is a result of atmospheric activity on precursors. NOX and ROG are known as the chief “precursors” of ozone. These compounds react in the presence of sunlight to produce ozone. PM2.5 includes fine particles that are found in smoke and haze and are emitted from all types of combustion activities (motor vehicles, power plants, wood burning, etc.) and certain industrial processes. PM10 includes both fine and coarse dust particles, and sources include crushing or grinding operations and dust from paved or unpaved roads.

As shown in Table 5 above, project construction would not exceed the applicable regional emissions thresholds, which are designed to provide limits below which project emissions would not significantly change regional air quality. Additionally, the project would implement standard construction measures compliant with mandatory SDAPCD rules and regulations and CARB’s In-Use Off-Road Diesel-Fueled Fleets Regulation, which would further reduce construction emissions. Therefore, project construction would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard, and impacts would be less than significant.

Long-term emissions of regional air pollutants occur from operational sources. As shown in Table 6 above, the project’s daily operational emissions would not exceed the applicable regional emissions thresholds for any pollutant.

These thresholds align with attainment of the NAAQS which were developed to protect the public health, specifically the health of “sensitive” populations, including asthmatics, children, and the elderly. Consequently, project operation would not impact any sensitive populations. Therefore, project operation would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard, and impacts would be less than significant.

3. Would the project expose sensitive receptors (including, but not limited to, schools, hospitals, resident care facilities, day-care centers and project residents) to substantial pollutant concentrations? Sensitive land uses include schools and schoolyards, parks and playgrounds, day care centers, nursing homes, hospitals, and residential communities. The nearest sensitive receptors include residential uses adjacent to as close as 40 feet from the western project boundary, 40 feet from the southern project boundary, and 135 feet from the eastern project boundary.

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Carbon Monoxide Hot Spots
Localized CO concentration is a direct function of motor vehicle activity at signalized intersections (e.g., idling time and traffic flow conditions), particularly during peak commute hours and meteorological conditions. The SDAB is a CO maintenance area under the federal CAA. This means that SDAB was previously a non-attainment area and is currently implementing a 10-year plan for continuing to meet and maintain air quality standards.

Due to increased requirements for cleaner vehicles, equipment, and fuels, CO levels in the state have dropped substantially. All air basins are attainment or maintenance areas for CO. Therefore, more recent screening procedures based on more current methodologies have been developed. The Bay Area Air Quality Management District (BAAQMD) developed a screening threshold in their 2022 CEQA Guidelines (BAAQMD 2022). These screening criteria are considered applicable in the SDAB because the San Francisco Bay Air Basin and the SDAB have the same CO maintenance designations. If the following screening criteria are met, operation of a project would result in less than significant impacts related to CO:
• The project would be consistent with an applicable congestion management program established by the County congestion management agency for designated roads or highways, the regional transportation plan, and local congestion management agency plans.
• Project-generated traffic would not increase traffic volumes at affected intersections to more than 44,000 vehicles per hour.
• Project-generated traffic would not increase traffic volumes at affected intersections to more than 24,000 vehicles per hour where vertical and/or horizontal mixing is substantially limited (e.g., tunnel, parking garage, bridge underpass, natural or urban street canyon, below-grade roadway).

Based on SANDAG daily roadway segment traffic projections (SANDAG 2022) and a peak hour volume equal to approximately 10 percent of the daily roadway segment volume, roadways in the vicinity of the project carry significantly less than both the 44,000 vehicles per hour and 24,000 vehicles per hour screening levels identified above. Therefore, the project’s traffic contribution of 374 would not generate a CO hot spot that could expose sensitive receptors to substantial pollutant concentration, and impacts would be less than significant.

Diesel Particulate Matter – Construction
Construction of the project and associated infrastructure would result in short-term diesel exhaust emissions from on-site heavy-duty equipment. Construction of the project would result in the generation of diesel-exhaust DPM emissions from the use of off-road diesel equipment required for site grading and excavation, paving, and other construction activities and on-road diesel equipment used to bring materials to and from the project site.

Generation of DPM from construction projects typically occurs in a single area for a short period. Construction is anticipated to last for approximately 14 months based on default CalEEMod phase durations. The dose to which the receptors are exposed is the primary factor used to determine health risk. Dose is a function of the concentration of a substance or substances in the environment and the extent of exposure that person has with the substance. Dose is positively correlated with time, meaning that a longer exposure period would result in a higher exposure level for the Maximally Exposed Individual. The risks estimated for a Maximally Exposed Individual are higher if a fixed exposure occurs over a longer period of time. According to the Office of Environmental Health Hazard Assessment (OEHHA), health risk assessments, which determine the exposure of sensitive receptors to toxic emissions, should be based on a 30-year exposure period; however, such assessments should be limited to the period/duration of activities associated with the project (OEHHA 2015). Thus, if the duration of proposed construction activities near any specific sensitive Mr. Troy Friedeck

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receptor were 14 months, the exposure would be less than 4 percent of the total 30-year exposure period (1.17 years divided by 30 years) used for health risk calculation. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, item 1 which would reduce construction equipment DPM emissions (refer to Section 1.1).

Because construction of the project would be short term (14 months) and the amount of heavy equipment required would be minimal, project construction would not expose nearby residents to substantial pollutant concentrations, and impacts would be less than significant.

Diesel Particulate Matter – Operation
As discussed in Section 2.1.2 above, the CARB handbook indicates that siting new sensitive land uses within 500 feet of a freeway or urban roads with 100,000 or more vehicles per day should be avoided when possible. The roadways within 500 feet of the project site include Aubrey Glen Drive and Mission Gorge Road. Based on SANDAG daily roadway traffic projections, volumes on these roadways are projected to be well less than 100,000 vehicles per day (SANDAG 2022). Therefore, the project would not expose sensitive receptors to substantial pollutant concentrations associated with diesel particulate matter during operation, and impacts would be less than significant.

4. Would the project result in other emissions (such as those leading to odors) adversely affecting a substantial number of people?
The potential for an odor impact is dependent on a number of variables, including the nature of the odor source, distance between the receptor and odor source, and local meteorological conditions. During construction, construction equipment may generate some nuisance odors. Sensitive receptors near the project site include residential uses; however, exposure to odors associated with project construction would be short term and temporary in nature (14 months), and only a minimal amount of construction equipment would be required. Therefore, project construction would not generate other emissions (such as those leading to odors) adversely affecting a substantial number of people, and impacts would be less than significant.

The following list provides some common types of facilities that are known producers of objectionable odors (Bay Area Air Quality Management District 2022). This list of facilities is not meant to be all-inclusive. • Wastewater Treatment Plant
• Wastewater Pumping Facilities
• Sanitary Landfill
• Transfer Station
• Composting Facility
• Petroleum Refinery
• Asphalt Batch Plant
• Chemical Manufacturing
• Fiberglass Manufacturing
• Painting/Coating Operations
• Rendering Plant
• Coffee Roaster
• Food Processing Facility
• Confined Animal Facility/Feed Lot/Dairy
• Green Waste and Recycling Operations
• Metal Smelting Plants
The project does not include any of these uses that are typically associated with odor complaints. The project does not propose any uses or activities that would result in potentially significant operational-source odor impacts.

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Therefore, project operation would not generate other emissions (such as those leading to odors) adversely affecting a substantial number of people, and impacts would be less than significant.

6.0 Conclusions
The primary goal of the RAQS is to reduce ozone precursor emissions. The project site was previously designated as General Commercial (GC) and was rezoned to High Density Residential R-22 (22 to 30 dwelling units per acre) as a part of the City’s Housing Element Rezone Program (City of Santee 2022). The Housing Element Rezone Program was developed prior to updates to the 2022 RAQS. Therefore, growth forecasting in the 2022 RAQS update utilized the previous land use designation. However, emissions generated by the project would be less than those that would be generated by a commercial project that would have been consistent with the land use designation and growth projections assumed in the RAQS update. Furthermore, as shown in Table 6 above, project emissions would not exceed the applicable significance thresholds for any criteria pollutants. Therefore, the project would not obstruct or conflict with the implementation of the RAQS, and impacts would be less than significant.

As shown in Table 5 above, project construction emissions would not exceed the applicable regional emissions thresholds, which are designed to provide limits below which project emissions would not significantly change regional air quality. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, items 1 through 3, 7, and 8 (refer to Section 1.1). The project would implement standard construction measures compliant with mandatory SDAPCD rules and regulations and CARB’s In-Use Off-Road Diesel-Fueled Fleets Regulation, which would further reduce construction emissions. Therefore, project construction would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard, and impacts would be less than significant. Additionally, construction emissions would be temporary, intermittent, and would cease at the end of project construction.

Long-term emissions of regional air pollutants occur from operational sources. As shown in Table 6 above, project operational emissions would not exceed the applicable regional emissions thresholds. Additionally, the project would be subject to Standard Project Condition No. 1 – Air Quality, items 4 through 9 (refer to Section 1.1). Therefore, project operation would not result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard, and impacts would be less than significant.

Sensitive land uses include schools and schoolyards, parks and playgrounds, daycare centers, nursing homes, hospitals, and residential communities. Residential uses are located adjacent to the project site. The project is not anticipated to result in a CO hot spot at project area intersections. Construction of the project and associated infrastructure would result in short-term diesel exhaust emissions from on-site heavy-duty equipment. However, because construction of the project would be short term (14 months) and the project would be subject to Standard Project Condition No. 1 – Air Quality, item 1, project construction is not anticipated to result in the exposure of nearby residents to substantial pollutant concentrations. Additionally, the project site is not located within 500 feet of a heavily travelled roadway. Therefore, the project would not expose sensitive receptors to substantial pollutant concentrations during construction or operation, and impacts would be less than significant.

The project does not include heavy industrial or agricultural uses that are typically associated with objectionable odors. The project would involve the use of diesel-powered construction equipment. Diesel exhaust may be noticeable temporarily at adjacent properties; however, construction activities would be temporary and only a minimal amount of construction equipment would be required. Therefore, the project would not generate other emissions (such as those leading to odors) adversely affecting a substantial number of people, and impacts would be less than significant.

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If you have any questions about the results of this analysis, please contact me at [email protected] or (619) 308-9333 extension 177.

Sincerely,
Jessica Fleming
Senior Air Quality Specialist
JLF:sh:jg
Attachment

7.0 References Cited
Bay Area Air Quality Management District (BAAQMD)
2022 California Environmental Quality Act Air Quality Guidelines. Adopted April 20, 2022.

California Air Pollution Control Officers Association
2022 California Emissions Estimator Model (CalEEMod). Version 2022.1.

California Air Resources Board (CARB)
2000 Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-Fueled Engines and Vehicles.

California Air Resources Board. Stationary Source Division, Mobile Source Control Division. October. 2005 Air Quality and Land Use Handbook: A Community Health Perspective. California Air Resources Board.

April.
2016 Ambient Air Quality Standards. May 4.
2024 California Air Quality Data Statistics. Available at http://www.arb.ca.gov/adam/welcome.html. Top 4 Summary and Hourly Listing. Accessed on July 12, 2024.

Linscott, Law & Greenspan Engineers (LLG)
2024 Traffic Analysis Intake Form. LLG Ref. 3-24-3939.

Office of Environmental Health Hazard Assessment (OEHHA) 2015 Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments (Guidance Manual), February.

San Diego Air Pollution Control District (SDAPCD)
2022 2022 Revision of the Regional Air Quality Strategy for San Diego County.

San Diego Association of Governments (SANDAG)
2002 (Not So) Brief Guide of Vehicular Traffic Generation Rates for the San Diego Region. April.

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2022 Transportation Forecast Information Center. Years 2025, 2035, and 2050 Series 14 traffic volumes.

Accessed at https://tfic.sandag.org/map.html. October 10.

Santee, City of
2020 Santee General Plan. https://www.cityofsanteeca.gov/government/planning-and-building/land-usecode/general-plan. 2022 City of Santee Housing Element Sixth Cycle 2021-2029. May 11. https://www.cityofsanteeca.gov/home/showpublisheddocument/8551/638066250344200000.

Western Regional Climate Center (WRCC)
2022 Cooperative Climatological Data Summaries. Accessed at https://wrcc.dri.edu/Climate/west_coop_summaries.php. October 17.

ATTACHMENT 1
CalEEMod Output
Aubrey Glen Detailed Report, 7/12/2024
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Aubrey Glen Detailed Report
Table of Contents

1. Basic Project Information

1.1. Basic Project Information

1.2. Land Use Types

1.3. User-Selected Emission Reduction Measures by Emissions Sector

2. Emissions Summary

2.1. Construction Emissions Compared Against Thresholds

2.2. Construction Emissions by Year, Unmitigated

2.4. Operations Emissions Compared Against Thresholds

2.5. Operations Emissions by Sector, Unmitigated

3. Construction Emissions Details

3.1. Demolition (2025) - Unmitigated

3.3. Site Preparation (2025) - Unmitigated

3.5. Grading (2025) - Unmitigated

3.7. Building Construction (2025) - Unmitigated

3.9. Building Construction (2026) - Unmitigated
Aubrey Glen Detailed Report, 7/12/2024
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3.11. Paving (2026) - Unmitigated

3.13. Architectural Coating (2026) - Unmitigated

4. Operations Emissions Details

4.1. Mobile Emissions by Land Use

4.1.1. Unmitigated

4.2. Energy

4.2.1. Electricity Emissions By Land Use - Unmitigated

4.2.3. Natural Gas Emissions By Land Use - Unmitigated

4.3. Area Emissions by Source

4.3.1. Unmitigated

4.4. Water Emissions by Land Use

4.4.1. Unmitigated

4.5. Waste Emissions by Land Use

4.5.1. Unmitigated

4.6. Refrigerant Emissions by Land Use

4.6.1. Unmitigated

4.7. Offroad Emissions By Equipment Type

4.7.1. Unmitigated
Aubrey Glen Detailed Report, 7/12/2024
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4.8. Stationary Emissions By Equipment Type

4.8.1. Unmitigated

4.9. User Defined Emissions By Equipment Type

4.9.1. Unmitigated

4.10. Soil Carbon Accumulation By Vegetation Type

4.10.1. Soil Carbon Accumulation By Vegetation Type - Unmitigated

4.10.2. Above and Belowground Carbon Accumulation by Land Use Type - Unmitigated

4.10.3. Avoided and Sequestered Emissions by Species - Unmitigated

5. Activity Data

5.1. Construction Schedule

5.2. Off-Road Equipment

5.2.1. Unmitigated

5.3. Construction Vehicles

5.3.1. Unmitigated

5.4. Vehicles

5.4.1. Construction Vehicle Control Strategies

5.5. Architectural Coatings

5.6. Dust Mitigation
Aubrey Glen Detailed Report, 7/12/2024
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5.6.1. Construction Earthmoving Activities

5.6.2. Construction Earthmoving Control Strategies

5.7. Construction Paving

5.8. Construction Electricity Consumption and Emissions Factors

5.9. Operational Mobile Sources

5.9.1. Unmitigated

5.10. Operational Area Sources

5.10.1. Hearths

5.10.1.1. Unmitigated

5.10.2. Architectural Coatings

5.10.3. Landscape Equipment

5.11. Operational Energy Consumption

5.11.1. Unmitigated

5.12. Operational Water and Wastewater Consumption

5.12.1. Unmitigated

5.13. Operational Waste Generation

5.13.1. Unmitigated

5.14. Operational Refrigeration and Air Conditioning Equipment Aubrey Glen Detailed Report, 7/12/2024
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5.14.1. Unmitigated

5.15. Operational Off-Road Equipment

5.15.1. Unmitigated

5.16. Stationary Sources

5.16.1. Emergency Generators and Fire Pumps

5.16.2. Process Boilers

5.17. User Defined

5.18. Vegetation

5.18.1. Land Use Change

5.18.1.1. Unmitigated

5.18.1. Biomass Cover Type

5.18.1.1. Unmitigated

5.18.2. Sequestration

5.18.2.1. Unmitigated

6. Climate Risk Detailed Report

6.1. Climate Risk Summary

6.2. Initial Climate Risk Scores

6.3. Adjusted Climate Risk Scores
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6.4. Climate Risk Reduction Measures

7. Health and Equity Details

7.1. CalEnviroScreen 4.0 Scores

7.2. Healthy Places Index Scores

7.3. Overall Health & Equity Scores

7.4. Health & Equity Measures

7.5. Evaluation Scorecard

7.6. Health & Equity Custom Measures

8. User Changes to Default Data
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1. Basic Project Information

1.1. Basic Project Information
Data Field Value
Project Name Aubrey Glen
Construction Start Date 1/1/2025
Operational Year 2026
Lead Agency City of Santee
Land Use Scale Project/site
Analysis Level for Defaults County
Windspeed (m/s) 2.60
Precipitation (days) 7.60
Location 32.836292138754175, -117.02807879137637
County San Diego
City Santee
Air District San Diego County APCD
Air Basin San Diego
TAZ 6524
EDFZ 12
Electric Utility San Diego Gas & Electric
Gas Utility San Diego Gas & Electric
App Version 2022.1.1.26

1.2. Land Use Types
Land Use Subtype Size Unit Lot Acreage Building Area (sq ft) Landscape Area (sq ft)
Special Landscape
Area (sq ft)
Population Description
Condo/Townhouse 52.0 Dwelling Unit 3.34 99,375 50,861 0.00 145 — Aubrey Glen Detailed Report, 7/12/2024
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1.3. User-Selected Emission Reduction Measures by Emissions Sector No measures selected

2. Emissions Summary

2.1. Construction Emissions Compared Against Thresholds Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Un/Mit. TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 1.52 1.28 10.7 14.9 0.02 0.43 0.35 0.79 0.40 0.08 0.48 — 2,892 2,892 0.12 0.05 1.69 2,912 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 34.7 34.7 31.7 30.9 0.05 1.37 7.81 9.18 1.26 3.97 5.23 — 5,452 5,452 0.22 0.11 0.04 5,472 Average
Daily
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 1.78 1.77 8.70 11.0 0.02 0.35 0.43 0.79 0.33 0.14 0.47 — 2,142 2,142 0.09 0.04 0.50 2,157 Annual
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 0.33 0.32 1.59 2.01 < 0.005 0.06 0.08 0.14 0.06 0.03 0.09 — 355 355 0.01 0.01 0.08 357 Exceeds
(Daily
Max)
— — — — — — — — — — — — — — — — — —
Threshol
d
— 250 250 550 250 — — 100 — — 67.0 — — — — — — —
Unmit. — No No No No — — No — — No — — — — — — —
Exceeds
(Average
Daily)
— — — — — — — — — — — — — — — — — —
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Threshol — 250 250 550 250 — — 100 — — 67.0 — — — — — — — d
Unmit. — No No No No — — No — — No — — — — — — —

2.2. Construction Emissions by Year, Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Year TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily -
Summer
(Max)
— — — — — — — — — — — — — — — — — —
2025 1.52 1.28 10.7 14.9 0.02 0.43 0.35 0.79 0.40 0.08 0.48 — 2,892 2,892 0.12 0.05 1.69 2,912 Daily -
Winter
(Max)
— — — — — — — — — — — — — — — — — —
2025 4.02 3.38 31.7 30.9 0.05 1.37 7.81 9.18 1.26 3.97 5.23 — 5,452 5,452 0.22 0.11 0.04 5,472 2026 34.7 34.7 10.2 14.5 0.02 0.38 0.35 0.73 0.35 0.08 0.43 — 2,863 2,863 0.12 0.05 0.04 2,881 Average
Daily
— — — — — — — — — — — — — — — — — —
2025 1.20 1.01 8.70 11.0 0.02 0.35 0.43 0.79 0.33 0.14 0.47 — 2,142 2,142 0.09 0.04 0.50 2,157 2026 1.78 1.77 0.49 0.74 < 0.005 0.02 0.02 0.04 0.02 < 0.005 0.02 — 124 124 0.01 < 0.005 0.03 125 Annual — — — — — — — — — — — — — — — — — —
2025 0.22 0.18 1.59 2.01 < 0.005 0.06 0.08 0.14 0.06 0.03 0.09 — 355 355 0.01 0.01 0.08 357 2026 0.33 0.32 0.09 0.14 < 0.005 < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 — 20.6 20.6 < 0.005 < 0.005 < 0.005 20.7

2.4. Operations Emissions Compared Against Thresholds
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Un/Mit. TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 3.75 3.63 1.03 10.6 0.02 0.04 1.58 1.61 0.04 0.40 0.44 24.2 2,227 2,251 2.57 0.08 6.90 2,347 Aubrey Glen Detailed Report, 7/12/2024
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Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 3.45 3.34 1.07 7.27 0.02 0.04 1.58 1.61 0.03 0.40 0.43 24.2 2,137 2,161 2.57 0.09 0.87 2,252 Average
Daily
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 3.46 3.35 0.99 7.96 0.02 0.04 1.40 1.44 0.03 0.36 0.39 24.2 1,967 1,991 2.56 0.08 3.10 2,081 Annual
(Max)
— — — — — — — — — — — — — — — — — —
Unmit. 0.63 0.61 0.18 1.45 < 0.005 0.01 0.26 0.26 0.01 0.06 0.07 4.01 326 330 0.42 0.01 0.51 345 Exceeds
(Daily
Max)
— — — — — — — — — — — — — — — — — —
Threshol
d
— 250 250 550 250 — — 100 — — 67.0 — — — — — — —
Unmit. — No No No No — — No — — No — — — — — — —
Exceeds
(Average
Daily)
— — — — — — — — — — — — — — — — — —
Threshol
d
— 250 250 550 250 — — 100 — — 67.0 — — — — — — —
Unmit. — No No No No — — No — — No — — — — — — —

2.5. Operations Emissions by Sector, Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Sector TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Mobile 1.15 1.05 0.73 7.57 0.02 0.01 1.58 1.59 0.01 0.40 0.41 — 1,848 1,848 0.09 0.07 6.19 1,877 Area 2.57 2.56 0.03 2.95 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 0.00 7.89 7.89 < 0.005 < 0.005 — 7.92 Energy 0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 369 369 0.05 < 0.005 — 371 Aubrey Glen Detailed Report, 7/12/2024
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Water — — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3 Waste — — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5 Refrig. — — — — — — — — — — — — — — — — 0.71 0.71
Total 3.75 3.63 1.03 10.6 0.02 0.04 1.58 1.61 0.04 0.40 0.44 24.2 2,227 2,251 2.57 0.08 6.90 2,347 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Mobile 1.12 1.03 0.80 7.16 0.02 0.01 1.58 1.59 0.01 0.40 0.41 — 1,766 1,766 0.09 0.07 0.16 1,790 Area 2.30 2.30 0.00 0.00 0.00 0.00 — 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 Energy 0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 369 369 0.05 < 0.005 — 371 Water — — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3 Waste — — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5 Refrig. — — — — — — — — — — — — — — — — 0.71 0.71
Total 3.45 3.34 1.07 7.27 0.02 0.04 1.58 1.61 0.03 0.40 0.43 24.2 2,137 2,161 2.57 0.09 0.87 2,252 Average
Daily
— — — — — — — — — — — — — — — — — —
Mobile 0.99 0.91 0.71 6.39 0.02 0.01 1.40 1.42 0.01 0.36 0.37 — 1,591 1,591 0.08 0.07 2.39 1,616 Area 2.43 2.43 0.01 1.45 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 0.00 3.89 3.89 < 0.005 < 0.005 — 3.90 Energy 0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 369 369 0.05 < 0.005 — 371 Water — — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3 Waste — — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5 Refrig. — — — — — — — — — — — — — — — — 0.71 0.71
Total 3.46 3.35 0.99 7.96 0.02 0.04 1.40 1.44 0.03 0.36 0.39 24.2 1,967 1,991 2.56 0.08 3.10 2,081 Annual — — — — — — — — — — — — — — — — — —
Mobile 0.18 0.17 0.13 1.17 < 0.005 < 0.005 0.26 0.26 < 0.005 0.06 0.07 — 263 263 0.01 0.01 0.40 267 Area 0.44 0.44 < 0.005 0.27 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 0.00 0.64 0.64 < 0.005 < 0.005 — 0.65 Energy 0.01 < 0.005 0.05 0.02 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 61.1 61.1 0.01 < 0.005 — 61.5 Water — — — — — — — — — — — 0.58 0.36 0.93 0.06 < 0.005 — 2.86 Waste — — — — — — — — — — — 3.43 0.00 3.43 0.34 0.00 — 12.0 Aubrey Glen Detailed Report, 7/12/2024
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Refrig. — — — — — — — — — — — — — — — — 0.12 0.12
Total 0.63 0.61 0.18 1.45 < 0.005 0.01 0.26 0.26 0.01 0.06 0.07 4.01 326 330 0.42 0.01 0.51 345

3. Construction Emissions Details

3.1. Demolition (2025) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

2.86 2.40 22.2 19.9 0.03 0.92 — 0.92 0.84 — 0.84 — 3,425 3,425 0.14 0.03 — 3,437 Demoliti
on
— — — — — — 0.58 0.58 — 0.09 0.09 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.16 0.13 1.22 1.09 < 0.005 0.05 — 0.05 0.05 — 0.05 — 188 188 0.01 < 0.005 — 188 Demoliti
on
— — — — — — 0.03 0.03 — < 0.005 < 0.005 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
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Off-Roa
Equipment

0.03 0.02 0.22 0.20 < 0.005 0.01 — 0.01 0.01 — 0.01 — 31.1 31.1 < 0.005 < 0.005 — 31.2 Demoliti
on
— — — — — — 0.01 0.01 — < 0.005 < 0.005 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.06 0.06 0.05 0.61 0.00 0.00 0.13 0.13 0.00 0.03 0.03 — 134 134 0.01 0.01 0.01 136 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.04 0.01 0.66 0.24 < 0.005 0.01 0.13 0.13 0.01 0.03 0.04 — 485 485 0.03 0.08 0.03 509 Average
Daily
— — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.03 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 7.43 7.43 < 0.005 < 0.005 0.01 7.54 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling < 0.005 < 0.005 0.04 0.01 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 — 26.6 26.6 < 0.005 < 0.005 0.02 27.9 Annual — — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 1.23 1.23 < 0.005 < 0.005 < 0.005 1.25 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 4.40 4.40 < 0.005 < 0.005 < 0.005 4.62

3.3. Site Preparation (2025) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
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Daily, — — — — — — — — — — — — — — — — — —
Summer
(Max)
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

3.94 3.31 31.6 30.2 0.05 1.37 — 1.37 1.26 — 1.26 — 5,295 5,295 0.21 0.04 — 5,314 Dust
From
Material
Movement
— — — — — — 7.67 7.67 — 3.94 3.94 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.05 0.05 0.43 0.41 < 0.005 0.02 — 0.02 0.02 — 0.02 — 72.5 72.5 < 0.005 < 0.005 — 72.8 Dust
From
Material
Movement
— — — — — — 0.11 0.11 — 0.05 0.05 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.01 0.01 0.08 0.08 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 12.0 12.0 < 0.005 < 0.005 — 12.1 Dust
From
Material
Movement
— — — — — — 0.02 0.02 — 0.01 0.01 — — — — — — —
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Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.08 0.07 0.06 0.71 0.00 0.00 0.15 0.15 0.00 0.03 0.03 — 157 157 0.01 0.01 0.02 159 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 2.17 2.17 < 0.005 < 0.005 < 0.005 2.20 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 < 0.005 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 0.36 0.36 < 0.005 < 0.005 < 0.005 0.36 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00

3.5. Grading (2025) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
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Off-Roa
Equipment

2.07 1.74 16.3 17.9 0.03 0.72 — 0.72 0.66 — 0.66 — 2,959 2,959 0.12 0.02 — 2,970 Dust
From
Material
Movement
— — — — — — 2.76 2.76 — 1.34 1.34 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.05 0.04 0.36 0.39 < 0.005 0.02 — 0.02 0.01 — 0.01 — 64.9 64.9 < 0.005 < 0.005 — 65.1 Dust
From
Material
Movement
— — — — — — 0.06 0.06 — 0.03 0.03 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.01 0.01 0.07 0.07 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 10.7 10.7 < 0.005 < 0.005 — 10.8 Dust
From
Material
Movement
— — — — — — 0.01 0.01 — 0.01 0.01 — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
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Daily, — — — — — — — — — — — — — — — — — —
Winter
(Max)
Worker 0.06 0.06 0.05 0.61 0.00 0.00 0.13 0.13 0.00 0.03 0.03 — 134 134 0.01 0.01 0.01 136 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 2.97 2.97 < 0.005 < 0.005 0.01 3.02 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 < 0.005 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 0.49 0.49 < 0.005 < 0.005 < 0.005 0.50 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00

3.7. Building Construction (2025) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

1.35 1.13 10.4 13.0 0.02 0.43 — 0.43 0.40 — 0.40 — 2,398 2,398 0.10 0.02 — 2,406 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
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Off-Roa
Equipment

1.35 1.13 10.4 13.0 0.02 0.43 — 0.43 0.40 — 0.40 — 2,398 2,398 0.10 0.02 — 2,406 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.83 0.70 6.46 8.06 0.01 0.27 — 0.27 0.25 — 0.25 — 1,483 1,483 0.06 0.01 — 1,488 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.15 0.13 1.18 1.47 < 0.005 0.05 — 0.05 0.04 — 0.04 — 245 245 0.01 < 0.005 — 246 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.16 0.15 0.11 1.73 0.00 0.00 0.32 0.32 0.00 0.07 0.07 — 355 355 0.02 0.01 1.33 361 Vendor 0.01 0.01 0.19 0.09 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 — 139 139 0.01 0.02 0.36 145 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.16 0.15 0.13 1.52 0.00 0.00 0.32 0.32 0.00 0.07 0.07 — 335 335 0.02 0.01 0.03 340 Vendor 0.01 0.01 0.19 0.09 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 — 139 139 0.01 0.02 0.01 145 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
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Worker 0.10 0.09 0.08 0.95 0.00 0.00 0.19 0.19 0.00 0.05 0.05 — 209 209 0.01 0.01 0.36 212 Vendor 0.01 < 0.005 0.12 0.05 < 0.005 < 0.005 0.02 0.02 < 0.005 0.01 0.01 — 86.1 86.1 < 0.005 0.01 0.10 89.9 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Worker 0.02 0.02 0.01 0.17 0.00 0.00 0.04 0.04 0.00 0.01 0.01 — 34.6 34.6 < 0.005 < 0.005 0.06 35.2 Vendor < 0.005 < 0.005 0.02 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 14.2 14.2 < 0.005 < 0.005 0.02 14.9 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00

3.9. Building Construction (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

1.28 1.07 9.85 13.0 0.02 0.38 — 0.38 0.35 — 0.35 — 2,397 2,397 0.10 0.02 — 2,405 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.02 0.01 0.13 0.18 < 0.005 0.01 — 0.01 < 0.005 — < 0.005 — 32.8 32.8 < 0.005 < 0.005 — 33.0 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
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Off-Roa
Equipment
< 0.005 < 0.005 0.02 0.03 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 5.44 5.44 < 0.005 < 0.005 — 5.46 Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.15 0.13 0.12 1.43 0.00 0.00 0.32 0.32 0.00 0.07 0.07 — 329 329 0.02 0.01 0.03 333 Vendor 0.01 < 0.005 0.18 0.08 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 — 137 137 0.01 0.02 0.01 143 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.02 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 4.54 4.54 < 0.005 < 0.005 0.01 4.61 Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 1.87 1.87 < 0.005 < 0.005 < 0.005 1.96 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 < 0.005 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 0.75 0.75 < 0.005 < 0.005 < 0.005 0.76 Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 0.31 0.31 < 0.005 < 0.005 < 0.005 0.32 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00

3.11. Paving (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
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Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.81 0.68 6.23 8.81 0.01 0.26 — 0.26 0.24 — 0.24 — 1,350 1,350 0.05 0.01 — 1,355 Paving 0.10 0.10 — — — — — — — — — — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.04 0.03 0.31 0.43 < 0.005 0.01 — 0.01 0.01 — 0.01 — 66.6 66.6 < 0.005 < 0.005 — 66.8 Paving 0.01 0.01 — — — — — — — — — — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.01 0.01 0.06 0.08 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 11.0 11.0 < 0.005 < 0.005 — 11.1 Paving < 0.005 < 0.005 — — — — — — — — — — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.08 0.07 0.06 0.76 0.00 0.00 0.17 0.17 0.00 0.04 0.04 — 176 176 0.01 0.01 0.02 178 Aubrey Glen Detailed Report, 7/12/2024
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Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.04 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 8.74 8.74 < 0.005 < 0.005 0.01 8.86 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 1.45 1.45 < 0.005 < 0.005 < 0.005 1.47 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00

3.13. Architectural Coating (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Onsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.15 0.12 0.86 1.13 < 0.005 0.02 — 0.02 0.02 — 0.02 — 134 134 0.01 < 0.005 — 134 Architect
ural
Coating
s

34.6 34.6 — — — — — — — — — — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Aubrey Glen Detailed Report, 7/12/2024
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Average
Daily
— — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent

0.01 0.01 0.04 0.06 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 6.58 6.58 < 0.005 < 0.005 — 6.61 Architect
ural
Coating
s

1.70 1.70 — — — — — — — — — — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Off-Roa
d
Equipm
ent
< 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 1.09 1.09 < 0.005 < 0.005 — 1.09 Architect
ural
Coating
s

0.31 0.31 — — — — — — — — — — — — — — — —
Onsite
truck

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Offsite — — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Worker 0.03 0.03 0.02 0.29 0.00 0.00 0.06 0.06 0.00 0.01 0.01 — 65.7 65.7 < 0.005 < 0.005 0.01 66.6 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
— — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 0.01 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 3.27 3.27 < 0.005 < 0.005 0.01 3.32 Aubrey Glen Detailed Report, 7/12/2024
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Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Annual — — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 < 0.005 < 0.005 0.00 0.00 < 0.005 < 0.005 0.00 < 0.005 < 0.005 — 0.54 0.54 < 0.005 < 0.005 < 0.005 0.55 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00

4. Operations Emissions Details

4.1. Mobile Emissions by Land Use

4.1.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se

1.15 1.05 0.73 7.57 0.02 0.01 1.58 1.59 0.01 0.40 0.41 — 1,848 1,848 0.09 0.07 6.19 1,877 Total 1.15 1.05 0.73 7.57 0.02 0.01 1.58 1.59 0.01 0.40 0.41 — 1,848 1,848 0.09 0.07 6.19 1,877 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se

1.12 1.03 0.80 7.16 0.02 0.01 1.58 1.59 0.01 0.40 0.41 — 1,766 1,766 0.09 0.07 0.16 1,790 Total 1.12 1.03 0.80 7.16 0.02 0.01 1.58 1.59 0.01 0.40 0.41 — 1,766 1,766 0.09 0.07 0.16 1,790 Annual — — — — — — — — — — — — — — — — — —
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Condo/T 0.18 0.17 0.13 1.17 < 0.005 < 0.005 0.26 0.26 < 0.005 0.06 0.07 — 263 263 0.01 0.01 0.40 267 ownhou
se
Total 0.18 0.17 0.13 1.17 < 0.005 < 0.005 0.26 0.26 < 0.005 0.06 0.07 — 263 263 0.01 0.01 0.40 267

4.2. Energy

4.2.1. Electricity Emissions By Land Use - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — — 26.5 26.5 0.02 < 0.005 — 27.7
Total — — — — — — — — — — — — 26.5 26.5 0.02 < 0.005 — 27.7 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — — 26.5 26.5 0.02 < 0.005 — 27.7
Total — — — — — — — — — — — — 26.5 26.5 0.02 < 0.005 — 27.7 Annual — — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — — 4.39 4.39 < 0.005 < 0.005 — 4.59 Total — — — — — — — — — — — — 4.39 4.39 < 0.005 < 0.005 — 4.59

4.2.3. Natural Gas Emissions By Land Use - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Aubrey Glen Detailed Report, 7/12/2024
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Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se

0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 343 343 0.03 < 0.005 — 344 Total 0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 343 343 0.03 < 0.005 — 344 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se

0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 343 343 0.03 < 0.005 — 344 Total 0.03 0.02 0.27 0.11 < 0.005 0.02 — 0.02 0.02 — 0.02 — 343 343 0.03 < 0.005 — 344 Annual — — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se

0.01 < 0.005 0.05 0.02 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 56.7 56.7 0.01 < 0.005 — 56.9 Total 0.01 < 0.005 0.05 0.02 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 56.7 56.7 0.01 < 0.005 — 56.9

4.3. Area Emissions by Source

4.3.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Source TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Hearths 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 Aubrey Glen Detailed Report, 7/12/2024
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Consum 2.13 2.13 — — — — — — — — — — — — — — — —
er
Product
s
Architect
ural
Coating
s

0.17 0.17 — — — — — — — — — — — — — — — —
Landsca
pe
Equipm
ent

0.28 0.26 0.03 2.95 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 7.89 7.89 < 0.005 < 0.005 — 7.92 Total 2.57 2.56 0.03 2.95 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 0.00 7.89 7.89 < 0.005 < 0.005 — 7.92 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Hearths 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 Consum
er
Product
s

2.13 2.13 — — — — — — — — — — — — — — — —
Architect
ural
Coating
s

0.17 0.17 — — — — — — — — — — — — — — — —
Total 2.30 2.30 0.00 0.00 0.00 0.00 — 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 Annual — — — — — — — — — — — — — — — — — —
Hearths 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 0.00 — 0.00 0.00 0.00 0.00 0.00 0.00 — 0.00 Consum
er
Product
s

0.39 0.39 — — — — — — — — — — — — — — — —
Architect
ural
Coating
s

0.03 0.03 — — — — — — — — — — — — — — — —
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Landsca 0.02 0.02 < 0.005 0.27 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 — 0.64 0.64 < 0.005 < 0.005 — 0.65 pe
Total 0.44 0.44 < 0.005 0.27 < 0.005 < 0.005 — < 0.005 < 0.005 — < 0.005 0.00 0.64 0.64 < 0.005 < 0.005 — 0.65

4.4. Water Emissions by Land Use

4.4.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3
Total — — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3
Total — — — — — — — — — — — 3.50 2.15 5.65 0.36 0.01 — 17.3 Annual — — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — 0.58 0.36 0.93 0.06 < 0.005 — 2.86 Total — — — — — — — — — — — 0.58 0.36 0.93 0.06 < 0.005 — 2.86

4.5. Waste Emissions by Land Use

4.5.1. Unmitigated
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Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5
Total — — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5
Total — — — — — — — — — — — 20.7 0.00 20.7 2.07 0.00 — 72.5 Annual — — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — 3.43 0.00 3.43 0.34 0.00 — 12.0
Total — — — — — — — — — — — 3.43 0.00 3.43 0.34 0.00 — 12.0

4.6. Refrigerant Emissions by Land Use

4.6.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
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Condo/T — — — — — — — — — — — — — — — — 0.71 0.71
ownhou
se
Total — — — — — — — — — — — — — — — — 0.71 0.71
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — — — — — — 0.71 0.71
Total — — — — — — — — — — — — — — — — 0.71 0.71
Annual — — — — — — — — — — — — — — — — — —
Condo/T
ownhou
se
— — — — — — — — — — — — — — — — 0.12 0.12
Total — — — — — — — — — — — — — — — — 0.12 0.12

4.7. Offroad Emissions By Equipment Type

4.7.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Equipm
ent
Type
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Annual — — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
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4.8. Stationary Emissions By Equipment Type

4.8.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Equipm
ent
Type
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Annual — — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —

4.9. User Defined Emissions By Equipment Type

4.9.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Equipm
ent
Type
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
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Annual — — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —

4.10. Soil Carbon Accumulation By Vegetation Type

4.10.1. Soil Carbon Accumulation By Vegetation Type - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Vegetati
on
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Annual — — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —

4.10.2. Above and Belowground Carbon Accumulation by Land Use Type - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Land
Use
TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —
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Annual — — — — — — — — — — — — — — — — — —
Total — — — — — — — — — — — — — — — — — —

4.10.3. Avoided and Sequestered Emissions by Species - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Species TOG ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — — —
Avoided — — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
Sequest
ered
— — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
Remove
d
— — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
— — — — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — — —
Avoided — — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
Sequest
ered
— — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
Remove
d
— — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
— — — — — — — — — — — — — — — — — — —
Annual — — — — — — — — — — — — — — — — — —
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Avoided — — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
Sequest
ered
— — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
Remove
d
— — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — — —
— — — — — — — — — — — — — — — — — — —

5. Activity Data

5.1. Construction Schedule
Phase Name Phase Type Start Date End Date Days Per Week Work Days per Phase Phase Description Demolition Demolition 1/1/2025 1/29/2025 5.00 20.0 —
Site Preparation Site Preparation 1/30/2025 2/6/2025 5.00 5.00 — Grading Grading 2/7/2025 2/18/2025 5.00 8.00 —
Building Construction Building Construction 2/19/2025 1/7/2026 5.00 230 — Paving Paving 1/8/2026 2/2/2026 5.00 18.0 —
Architectural Coating Architectural Coating 2/3/2026 2/28/2026 5.00 18.0 —

5.2. Off-Road Equipment

5.2.1. Unmitigated
Phase Name Equipment Type Fuel Type Engine Tier Number per Day Hours Per Day Horsepower Load Factor Demolition Concrete/Industrial
Saws
Diesel Average 1.00 8.00 33.0 0.73
Demolition Excavators Diesel Average 3.00 8.00 36.0 0.38 Demolition Rubber Tired Dozers Diesel Average 2.00 8.00 367 0.40 Aubrey Glen Detailed Report, 7/12/2024
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Site Preparation Rubber Tired Dozers Diesel Average 3.00 8.00 367 0.40 Site Preparation Tractors/Loaders/Back
hoes
Diesel Average 4.00 8.00 84.0 0.37
Grading Excavators Diesel Average 1.00 8.00 36.0 0.38
Grading Graders Diesel Average 1.00 8.00 148 0.41
Grading Rubber Tired Dozers Diesel Average 1.00 8.00 367 0.40 Grading Tractors/Loaders/Back
hoes
Diesel Average 3.00 8.00 84.0 0.37
Building Construction Cranes Diesel Average 1.00 7.00 367 0.29 Building Construction Forklifts Diesel Average 3.00 8.00 82.0 0.20 Building Construction Generator Sets Diesel Average 1.00 8.00 14.0 0.74 Building Construction Tractors/Loaders/Back
hoes
Diesel Average 3.00 7.00 84.0 0.37
Building Construction Welders Diesel Average 1.00 8.00 46.0 0.45 Paving Cement and Mortar
Mixers
Diesel Average 2.00 6.00 10.0 0.56
Paving Pavers Diesel Average 1.00 8.00 81.0 0.42
Paving Paving Equipment Diesel Average 2.00 6.00 89.0 0.36 Paving Rollers Diesel Average 2.00 6.00 36.0 0.38
Paving Tractors/Loaders/Back
hoes
Diesel Average 1.00 8.00 84.0 0.37
Architectural Coating Air Compressors Diesel Average 1.00 6.00 37.0 0.48

5.3. Construction Vehicles

5.3.1. Unmitigated
Phase Name Trip Type One-Way Trips per Day Miles per Trip Vehicle Mix Demolition — — — —
Demolition Worker 15.0 12.0 LDA,LDT1,LDT2
Demolition Vendor — 7.63 HHDT,MHDT
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Demolition Hauling 6.75 20.0 HHDT
Demolition Onsite truck—— HHDT
Site Preparation————
Site Preparation Worker 17.5 12.0 LDA,LDT1,LDT2
Site Preparation Vendor— 7.63 HHDT,MHDT
Site Preparation Hauling 0.00 20.0 HHDT
Site Preparation Onsite truck—— HHDT
Grading————
Grading Worker 15.0 12.0 LDA,LDT1,LDT2
Grading Vendor— 7.63 HHDT,MHDT
Grading Hauling 0.00 20.0 HHDT
Grading Onsite truck—— HHDT
Building Construction————
Building Construction Worker 37.4 12.0 LDA,LDT1,LDT2
Building Construction Vendor 5.56 7.63 HHDT,MHDT
Building Construction Hauling 0.00 20.0 HHDT
Building Construction Onsite truck—— HHDT
Paving————
Paving Worker 20.0 12.0 LDA,LDT1,LDT2
Paving Vendor— 7.63 HHDT,MHDT
Paving Hauling 0.00 20.0 HHDT
Paving Onsite truck—— HHDT
Architectural Coating————
Architectural Coating Worker 7.49 12.0 LDA,LDT1,LDT2
Architectural Coating Vendor— 7.63 HHDT,MHDT
Architectural Coating Hauling 0.00 20.0 HHDT
Architectural Coating Onsite truck—— HHDT
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5.4. Vehicles

5.4.1. Construction Vehicle Control Strategies
Non-applicable. No control strategies activated by user.

5.5. Architectural Coatings
Phase Name Residential Interior Area
Coated (sq ft)
Residential Exterior Area
Coated (sq ft)
Non-Residential Interior Area
Coated (sq ft)
Non-Residential Exterior Area
Coated (sq ft)
Parking Area Coated (sq ft)
Architectural Coating 201,234 67,078 0.00 0.00 —

5.6. Dust Mitigation

5.6.1. Construction Earthmoving Activities
Phase Name Material Imported (cy) Material Exported (cy) Acres Graded (acres) Material Demolished (Building Square Footage)
Acres Paved (acres)
Demolition 0.00 0.00 0.00 11,700 —
Site Preparation — — 7.50 0.00 —
Grading — — 8.00 0.00 —
Paving 0.00 0.00 0.00 0.00 0.70

5.6.2. Construction Earthmoving Control Strategies
Control Strategies Applied Frequency (per day) PM10 Reduction PM2.5 Reduction Water Exposed Area 2 61% 61%

5.7. Construction Paving
Land Use Area Paved (acres) % Asphalt
Condo/Townhouse 0.70 100%
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5.8. Construction Electricity Consumption and Emissions Factors kWh per Year and Emission Factor (lb/MWh)
Year kWh per Year CO2 CH4 N2O
2025 0.00 589 0.03 < 0.005
2026 0.00 589 0.03 < 0.005

5.9. Operational Mobile Sources

5.9.1. Unmitigated
Land Use Type Trips/Weekday Trips/Saturday Trips/Sunday Trips/Year VMT/Weekday VMT/Saturday VMT/Sunday VMT/Year Condo/Townhouse 236 263 202 85,790 2,007 2,233 1,720 729,440

5.10. Operational Area Sources

5.10.1. Hearths

5.10.1.1. Unmitigated
Hearth Type Unmitigated (number)
Condo/Townhouse —
Wood Fireplaces 0
Gas Fireplaces 0
Propane Fireplaces 0
Electric Fireplaces 0
No Fireplaces 52
Conventional Wood Stoves 0
Catalytic Wood Stoves 0
Non-Catalytic Wood Stoves 0
Pellet Wood Stoves 0
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5.10.2. Architectural Coatings
Residential Interior Area Coated (sq
ft)
Residential Exterior Area Coated (sq
ft)
Non-Residential Interior Area Coated
(sq ft)
Non-Residential Exterior Area
Coated (sq ft)
Parking Area Coated (sq ft)
201234.375 67,078 0.00 0.00 —

5.10.3. Landscape Equipment
Season Unit Value
Snow Days day/yr 0.00
Summer Days day/yr 180

5.11. Operational Energy Consumption

5.11.1. Unmitigated
Electricity (kWh/yr) and CO2 and CH4 and N2O and Natural Gas (kBTU/yr) Land Use Electricity (kWh/yr) CO2 CH4 N2O Natural Gas (kBTU/yr) Condo/Townhouse 214,726 45.1 0.0330 0.0040 1,069,366

5.12. Operational Water and Wastewater Consumption

5.12.1. Unmitigated
Land Use Indoor Water (gal/year) Outdoor Water (gal/year) Condo/Townhouse 1,826,920 928,981

5.13. Operational Waste Generation

5.13.1. Unmitigated
Land Use Waste (ton/year) Cogeneration (kWh/year)
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Condo/Townhouse 38.4 —

5.14. Operational Refrigeration and Air Conditioning Equipment

5.14.1. Unmitigated
Land Use Type Equipment Type Refrigerant GWP Quantity (kg) Operations Leak Rate Service Leak Rate Times Serviced Condo/Townhouse Average room A/C &
Other residential A/C
and heat pumps
R-410A 2,088 < 0.005 2.50 2.50 10.0
Condo/Townhouse Household
refrigerators and/or
freezers
R-134a 1,430 0.12 0.60 0.00 1.00

5.15. Operational Off-Road Equipment

5.15.1. Unmitigated
Equipment Type Fuel Type Engine Tier Number per Day Hours Per Day Horsepower Load Factor

5.16. Stationary Sources

5.16.1. Emergency Generators and Fire Pumps
Equipment Type Fuel Type Number per Day Hours per Day Hours per Year Horsepower Load Factor

5.16.2. Process Boilers
Equipment Type Fuel Type Number Boiler Rating (MMBtu/hr) Daily Heat Input (MMBtu/day) Annual Heat Input (MMBtu/yr)

5.17. User Defined
Equipment Type Fuel Type
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5.18. Vegetation

5.18.1. Land Use Change

5.18.1.1. Unmitigated
Vegetation Land Use Type Vegetation Soil Type Initial Acres Final Acres

5.18.1. Biomass Cover Type

5.18.1.1. Unmitigated
Biomass Cover Type Initial Acres Final Acres

5.18.2. Sequestration

5.18.2.1. Unmitigated
Tree Type Number Electricity Saved (kWh/year) Natural Gas Saved (btu/year)

6. Climate Risk Detailed Report

6.1. Climate Risk Summary
Cal-Adapt midcentury 2040–2059 average projections for four hazards are reported below for your project location. These are under Representation Concentration Pathway (RCP) 8.5 which assumes GHG emissions will continue to rise strongly through 2050 and then plateau around 2100.

Climate Hazard Result for Project Location Unit
Temperature and Extreme Heat 12.1 annual days of extreme heat Extreme Precipitation 3.85 annual days with precipitation above 20 mm Sea Level Rise — meters of inundation depth
Wildfire 21.8 annual hectares burned
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Temperature and Extreme Heat data are for grid cell in which your project are located. The projection is based on the 98th historical percentile of daily maximum/minimum temperatures from observed historical data (32 climate model ensemble from Cal-Adapt, 2040–2059 average under RCP 8.5). Each grid cell is 6 kilometers (km) by 6 km, or 3.7 miles (mi) by 3.7 mi.

Extreme Precipitation data are for the grid cell in which your project are located. The threshold of 20 mm is equivalent to about ¾ an inch of rain, which would be light to moderate rainfall if received over a full day or heavy rain if received over a period of 2 to 4 hours. Each grid cell is 6 kilometers (km) by 6 km, or 3.7 miles (mi) by 3.7 mi.

Sea Level Rise data are for the grid cell in which your project are located. The projections are from Radke et al. (2017), as reported in Cal-Adapt (Radke et al., 2017, CEC-500-2017-008), and consider inundation location and depth for the San Francisco Bay, the Sacramento-San Joaquin River Delta and California coast resulting different increments of sea level rise coupled with extreme storm events. Users may select from four scenarios to view the range in potential inundation depth for the grid cell. The four scenarios are: No rise, 0.5 meter, 1.0 meter, 1.41 meters Wildfire data are for the grid cell in which your project are located. The projections are from UC Davis, as reported in Cal-Adapt (2040–2059 average under RCP 8.5), and consider historical data of climate, vegetation, population density, and large (> 400 ha) fire history. Users may select from four model simulations to view the range in potential wildfire probabilities for the grid cell. The four simulations make different assumptions about expected rainfall and temperature are: Warmer/drier (HadGEM2-ES), Cooler/wetter (CNRM-CM5), Average conditions (CanESM2), Range of different rainfall and temperature possibilities (MIROC5). Each grid cell is 6 kilometers (km) by 6 km, or 3.7 miles (mi) by 3.7 mi.

6.2. Initial Climate Risk Scores
Climate Hazard Exposure Score Sensitivity Score Adaptive Capacity Score Vulnerability Score Temperature and Extreme Heat N/A N/A N/A N/A
Extreme Precipitation N/A N/A N/A N/A
Sea Level Rise 1 0 0 N/A
Wildfire 1 0 0 N/A
Flooding 0 0 0 N/A
Drought N/A N/A N/A N/A
Snowpack Reduction N/A N/A N/A N/A
Air Quality Degradation N/A N/A N/A N/A
The sensitivity score reflects the extent to which a project would be adversely affected by exposure to a climate hazard. Exposure is rated on a scale of 1 to 5, with a score of 5 representing the greatest exposure.

The adaptive capacity of a project refers to its ability to manage and reduce vulnerabilities from projected climate hazards. Adaptive capacity is rated on a scale of 1 to 5, with a score of 5 representing the greatest ability to adapt.

The overall vulnerability scores are calculated based on the potential impacts and adaptive capacity assessments for each hazard. Scores do not include implementation of climate risk reduction measures.

6.3. Adjusted Climate Risk Scores
Climate Hazard Exposure Score Sensitivity Score Adaptive Capacity Score Vulnerability Score Temperature and Extreme Heat N/A N/A N/A N/A
Extreme Precipitation N/A N/A N/A N/A
Sea Level Rise 1 1 1 2
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Wildfire 1 1 1 2
Flooding 1 1 1 2
Drought N/A N/A N/A N/A
Snowpack Reduction N/A N/A N/A N/A
Air Quality Degradation N/A N/A N/A N/A
The sensitivity score reflects the extent to which a project would be adversely affected by exposure to a climate hazard. Exposure is rated on a scale of 1 to 5, with a score of 5 representing the greatest exposure.

The overall vulnerability scores are calculated based on the potential impacts and adaptive capacity assessments for each hazard. Scores include implementation of climate risk reduction measures.

6.4. Climate Risk Reduction Measures

7. Health and Equity Details

7.1. CalEnviroScreen 4.0 Scores
The maximum CalEnviroScreen score is 100. A high score (i.e., greater than 50) reflects a higher pollution burden compared to other census tracts in the state.

Indicator Result for Project Census Tract
Exposure Indicators —
AQ-Ozone 57.1
AQ-PM 43.8
AQ-DPM 45.9
Drinking Water 11.0
Lead Risk Housing 19.9
Pesticides 0.00
Toxic Releases 25.1
Traffic 49.0
Effect Indicators —
CleanUp Sites 0.00
Groundwater 0.00
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Haz Waste Facilities/Generators 26.7
Impaired Water Bodies 77.3
Solid Waste 35.7
Sensitive Population —
Asthma 22.1
Cardio-vascular 11.8
Low Birth Weights 28.4
Socioeconomic Factor Indicators —
Education 16.8
Housing 25.3
Linguistic 17.3
Poverty 36.4
Unemployment 58.4

7.2. Healthy Places Index Scores
The maximum Health Places Index score is 100. A high score (i.e., greater than 50) reflects healthier community conditions compared to other census tracts in the state.

Indicator Result for Project Census Tract
Economic —
Above Poverty 77.85191839
Employed 55.33170794
Median HI 53.2144232
Education —
Bachelor's or higher 49.60862312
High school enrollment 100
Preschool enrollment 51.87989221
Transportation —
Auto Access 70.20402926
Active commuting 12.35724368
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Social —
2-parent households 13.26831772
Voting 82.90773771
Neighborhood —
Alcohol availability 70.62748621
Park access 62.68446041
Retail density 64.45528038
Supermarket access 10.67624791
Tree canopy 40.39522649
Housing —
Homeownership 71.88502502
Housing habitability 87.19363531
Low-inc homeowner severe housing cost burden 65.7128192 Low-inc renter severe housing cost burden 80.803285
Uncrowded housing 71.88502502
Health Outcomes —
Insured adults 78.05723085
Arthritis 0.0
Asthma ER Admissions 75.6
High Blood Pressure 0.0
Cancer (excluding skin) 0.0
Asthma 0.0
Coronary Heart Disease 0.0
Chronic Obstructive Pulmonary Disease 0.0
Diagnosed Diabetes 0.0
Life Expectancy at Birth 40.6
Cognitively Disabled 24.2
Physically Disabled 42.3
Aubrey Glen Detailed Report, 7/12/2024
46 / 47
Heart Attack ER Admissions 77.2
Mental Health Not Good 0.0
Chronic Kidney Disease 0.0
Obesity 0.0
Pedestrian Injuries 59.8
Physical Health Not Good 0.0
Stroke 0.0
Health Risk Behaviors—
Binge Drinking 0.0
Current Smoker 0.0
No Leisure Time for Physical Activity 0.0
Climate Change Exposures—
Wildfire Risk 56.9
SLR Inundation Area 0.0
Children 67.0
Elderly 16.8
English Speaking 87.3
Foreign-born 8.0
Outdoor Workers 57.9
Climate Change Adaptive Capacity—
Impervious Surface Cover 47.9
Traffic Density 57.7
Traffic Access 23.0
Other Indices—
Hardship 34.9
Other Decision Support—
2016 Voting 81.8
Aubrey Glen Detailed Report, 7/12/2024
47 / 47

7.3. Overall Health & Equity Scores
Metric Result for Project Census Tract
CalEnviroScreen 4.0 Score for Project Location (a) 13.0 Healthy Places Index Score for Project Location (b) 62.0 Project Located in a Designated Disadvantaged Community (Senate Bill 535) No Project Located in a Low-Income Community (Assembly Bill 1550) No Project Located in a Community Air Protection Program Community (Assembly Bill 617) No a: The maximum CalEnviroScreen score is 100. A high score (i.e., greater than 50) reflects a higher pollution burden compared to other census tracts in the state. b: The maximum Health Places Index score is 100. A high score (i.e., greater than 50) reflects healthier community conditions compared to other census tracts in the state.

7.4. Health & Equity Measures
No Health & Equity Measures selected.

7.5. Evaluation Scorecard
Health & Equity Evaluation Scorecard not completed.

7.6. Health & Equity Custom Measures
No Health & Equity Custom Measures created.

8. User Changes to Default Data
Screen Justification
Land Use 52 units, 3.34 acres, 50,861 sf open space
Construction: Paving 0.7 acres paved
Operations: Vehicle Data 4.54 weekday trips/unit
Weekend trip rates adjusted proportionately
Operations: Hearths No fireplaces or wood stoves
Drainage Study
For
Townsend Multi-Family
Preliminary Engineering
RICK Job No.19964
August 30, 2024
November 7, 2024
January 29, 2025
Revised March 21, 2025

DRAINAGE STUDY
FOR

TOWNSEND MULTI-FAMILY
Preliminary Engineering
RICK Job Number 19964
___________________________________
Shavger Rekani, PE
PE #90893, Exp. 03/26
Prepared For:

KB Homes Coastal
9915 Mira Mesa Boulevard, Suite 600
San Diego, California 90025
Prepared By:

RICK
Water Resources Department
5620 Friars Road
San Diego, California 92110-2596
(619) 291-0707
August 30, 2024
November 7, 2024
January 29, 2025
Revised March 21, 2025
Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
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Revised: 3-21-25

TABLE OF CONTENTS
REVISION PAGE DATED NOVEMBER 7, 2024…………………...……...…………..……………...i

1.0 INTRODUCTION ............................................................................................................ 1

2.0 HYDROLOGY ................................................................................................................. 3

3.0 HYDRAULICS ................................................................................................................ 7

4.0 DETENTION ANALYSES ............................................................................................... 9

5.0 CONCLUSION ............................................................................................................... 9 Figures:

Figure 1: Vicinity Map ................................................................................................................. 3 Tables:

Table 1: Subarea Hydrologic Processes (Codes) ........................................................................ 4 Table 2.1: Summary of Hydrologic Conditions............................................................................ 6 Appendices:

Appendix A: Modified Rational Method Output [Pre-project] Appendix B: Modified Rational Method Output [Post-project] Appendix C: Backup for Weighted Runoff Coefficients
Appendix D: Inlet Sizing
Appendix E: Storm Drain Sizing Calculations
Appendix F: Emergency Overflow Calculations
Map Pockets:

Map Pocket 1: Drainage Study Map for Townsend Multi-Family [Pre-Project] Map Pocket 2: Drainage Study Map for Townsend Multi-Family [Post-Project] Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25

DECLARATION OF RESPONSIBLE CHARGE

I HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THE DRAINAGE

REPORT FOR THIS PROJECT, THAT I HAVE EXERCISED RESPONSIBLE CHARGE OVER THIS DRAINAGE REPORT AS DEFINED IN SECTION 6703 OF THE BUSINESS

AND PROFESSIONALS CODE, AND OPINE THAT THE DRAINAGE REPORT IS CONSISTENT WITH CURRENT STANDARDS.

I UNDERSTAND THAT THE CHECK OF THE DRAINAGE REPORT BY THE CITY OF

SANTEE IS CONFINED TO A REVIEW ONLY AND DOES NOT RELIEVE ME, AS THE

ENGINEER OF WORK FOR THE DRAINAGE REPORT, OF ANY RESPONSIBILITIES FOR THE DRAINAGE REPORT.

Shavger Rekani P.E. #90893 Exp. 03/26 DATE:
3/21/2025
Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
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Revised: 3-21-25
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DRAINAGE STUDY FOR

AUBREY GLEN
Revision Page
March 21, 2025
This Drainage Study presents a revision to January 29, 2025, report pursuant to the City of Santee plan check comments received March 14, 2025. The following text identifies the plan check comments along with the responses in bold.

Drainage Study Review Comments (3rd Submittal) – Dr. Luis A. Parra & William O’Gorman (Dated 3/14/2025)
I. Drainage Study Review

1. EOW needs to sign and stamp report prior to approval. Change “County of San Diego” to “City of Santee” in Declaration of Responsible Charge. There are only minor corrections pending and it is anticipated that the drainage study will be approved next submittal.

Noted; signature and stamp has been provided. Declaration of Responsible Charge has been updated to note the City of Santee.

2. The Type ‘F’ catch basin is located behind a 10 ft retaining wall on off-site property. Who will be responsible for the maintenance of this inlet? If it is the developer, provide a letter of permission from the Laurel Heights HOA and an adequate access easement for maintenance (to be granted prior to tentative map approval). a. Second & Third Review: EOW has stated the developer is in progress obtaining a letter of permission and easement from the Laurel Heights HOA. Comment will remain open until permission is granted.

Noted.

3. PDF page 37 [Now page 39]: there is an error in the user-specified runoff coefficient: a value of 0.06 was used (see end of page). Change to 0.69 (as in 50 and 100 year storm events, see pages PDF 54 and PDF 71).
a. Third Review: EOW has stated that this sub-basin C-Value has been corrected, but this is not apparent in the report. The AES run is from November 2024. Please ensure that these pages have been swapped out and update any results on the summary tables or drainage exhibits if necessary.

Latest AES run for the 10-year event has been included in this submittal with the appropriate runoff coefficient of 0.69.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25
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4. PDF page 38 [now page 40]: Subarea (acres) = 0.10 is different than subarea (acres) =

0.06 of pdf page 55 [now page 57] and pdf page 72[now page 74]. Please reconcile. a. Third Review: EOW has stated that this sub-basin area has been corrected, but this is not apparent in the report (page 40 shows 0.10 acres again). The AES run is from November 2024. Please ensure that these pages have been swapped out and update any results on the summary tables or drainage exhibits if necessary.

Latest AES run for the 10-year event has been included in this submittal with the appropriate area of 0.06 acres.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25
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DRAINAGE STUDY FOR

AUBREY GLEN
Revision Page
January 29, 2025
This Drainage Study presents a revision to the November 7, 2024, report pursuant to the City of Santee plan check comments received December 19, 2024. The following text identifies the plan check comments along with the responses in bold.

Drainage Study Review Comments (2nd Submittal) – Dr. Luis A. Parra & William O’Gorman (Dated 12/19/2024)
I. Drainage Study Review
i.1. Main Document

1. EOW needs to sign and stamp the report prior to approval.

Noted; signature and stamp to be provided in later submittal prior to approval.

5. Section 2.2: Table 2.1 and text below are in contradiction: (SECOND REVIEW) – The text does not appear to be changed.

Text has been updated accordingly.

23. Map Pocket, Pre-Development: (SECOND REVIEW) – The water-path does not appear to be added.

Additional water path has been added to exhibit.
ii.1. Drainage Study & Tentative Map Comments

29. (SECOND REVIEW) – EOW has stated the developer is in progress obtaining a letter of permission and easement from the Laurel Heights HOA. Comment will remain open until permission is granted.

Noted.

31. (SECOND REVIEW) – Please show pipe elevations of the existing sewer main and water main in Mission Gorge Road.

Existing sewer main IEs provided within Mission Gorge Road. Additional call-out at crossing has been provided. Existing water main depth to be field verified for construction drawings.

38. (SECOND REVIEW) – Confirm if “swale” in Section D-D on sheet 2 should be “Browditch”.

Section D-D has been updated to reflect "brow ditch".

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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New 2nd Round Comments

39. Section 1.2, Post-Project Condition, first paragraph: It says: “… and a portion Basin 200 that drains…” It should say: “… an on a portion of Basin 200 that drains …” or the description narrative should change to make sense grammatically.

Paragraph has been updated accordingly to state “Offsite flows are found in Basin 100 and on a portion Basin 200 that drains the existing Laurel Heights development”.

40. PDF page 37: there is an error in the user-specified runoff coefficient: a value of 0.06 was used (see end of page). Change to 0.69 (as in 50- and 100-year storm events, see pages PDF 54 and PDF 71).

Use-specified runoff coefficient has been updated from 0.06 to 0.69.

41. PDF page 38: Subarea (acres) = 0.10 is different than subarea (acres) = 0.06 of pdf page 55 and pdf page 72. Please reconcile.

Subarea has been updated from 0.10 acres to 0.06 acres.

42. It caught REC attention than in previous version of the Drainage Report, Q10-post, Q50- post and Q100-post were, respectively, 23.4 cfs, 32.1 cfs and 33.8 cfs (Table 2.1), while in the new version those values are 31.47 cfs, 33.55 cfs and 33.90 cfs. We cannot review the assumptions of the AES software that were made before for 10 and 50 years in postdevelopment as the report was incomplete, so we do not know why Q10 increased so much, Q50 increased over 1.4 cfs, and Q100 remained almost identical. However, we suspect that the problem is related with the USER-SPECIFIED VALUES in AES as they are all identical regardless of the return period (for undetained node 230 Q = 20 cfs, and node 270 = 10.97 regardless of return period). Please revise all user specified hydrology information conditions at node 230 and 270 for all conditions. Note: for the previous August version, user-specified values at node 230 were 14.10 cfs, 19.08 cfs, and 20.00 cfs for 10- year, 50 year and 100-year return period respectively. Also, at node 270, the values were

7.39 cfs, 10.40 cfs, and 10.97 cfs for 10, 50 and 100 years respectively. For the new version the value 20.00 cfs and the value 10.97 cfs were used regardless of return period, which seems to indicate that the real 50- and 10-year values were not used and the AES models need to be updated.

The differences between the 10-, 50-, and 100-year AES post values stem from the user-specified values (Code 7) used in the AES post-project analysis. These userspecified values, which reference the Q100 values at Nodes 230 and 270, are derived from the Drainage Study for Laurel Heights, dated July 19, 2021, by RICK Engineering (TM 2020-02, DR 2020-04). Since Q10 and Q50 values were not required for the Laurel Heights project, a conservative approach was taken by using a ratio of P6 between the 10-year/100-year and 50-year/100-year flows (i.e., P6,Q10/P6,Q100 & P6,Q50/P6,Q100) to approximate flowrate values. This method resulted in approximately 70% of the Q100 value for the 10-year storm, and about 95% of the Q100 value for the 50-year storm. Based on this analysis, the user-specified flow Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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rates at Node 230 were 14.10 cfs, 19.08 cfs, and 20.00 cfs for the 10-, 50-, and 100- year return periods, respectively. At Node 270, the values were 7.39 cfs, 10.40 cfs, and 10.97 cfs for the 10-, 50-, and 100-year return periods, respectively. These values were provided in the previous August report and will be incorporated into the updated AES analysis.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
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Revised: 3-21-25
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DRAINAGE STUDY FOR

AUBREY GLEN
Revision Page
November 7, 2024
This Drainage Study presents a revision to the August 30, 2024 report pursuant to the City of Santee plan check comments received October 24, 2024. The following text identifies the plan check comments along with the responses in bold.

Drainage Study Review Comments – Dr. Luis A. Parra & William O’Gorman (Dated 10/21/2024) I. Drainage Study Review
i.1. Main Document

1. EOW needs to sign and stamp the report prior to approval. Also, a declaration of responsible charge is needed in the report.

Noted; signature and stamp to be provided in later submittal prior to approval.

Declaration of responsible charge added to beginning of report.

2. Correct the following sentence from Section 1.2, Pre-Project Conditions: “Offsite flows adjacent to the project site are represented by Basin 100.” It turns out that some offsite area is also in Basin 200.

Sentence from Section 1.2 pre-project has been corrected as requested.

3. Correct the following sentence from Section 1.2, Post-Project Conditions or expand explanation: “… with offsite flows in Basin 100.” Some offsite area is also in Basin 200.

Sentence from Section 1.2 post-project has been corrected as requested.

4. The conditions of the emergency overflow are not clear. The document only mentions that “drainage from the project site will overtop the frontage of the site and drain onto Mission Gorge Road.” No details are provided, nor design calculations. Please include.

A detail has been provided in Appendix F for the emergency overflow calculations.

5. Section 2.2: Table 2.1 and text below are in contradiction: per Table 2.1, the Tributary Area has not changed, but per the text below, tributary areas have decreased. Correct the text below Table 2.1.

The text following Table 2.1 has been revised, the tributary area has not changed.

6. Section 2.2: Minor corrections in the long paragraph below Table 2.1: It says “… results in a decrease of runoff.” It should say “… results in a decrease of runoff peak flow.” At the end, it says “… it can be decided that detention is not required for this project.” Probably makes more sense as “… it can be concluded that detention is not required for this project.”
Comment noted, this sentence has been updated.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25
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7. Section 3.1.2: Type B inlet in a Sump equation: This is not the typical inlet in a sump equation, as it does not depend on the depth (meaning that there is an assumption about the depth that is not explained there). Please explain or correct.

The equation in Section 3.1.2 has been removed and instead Section 3.1.2 of the report references equations 2-8 and 2-9 from the County of San Diego Hydraulic Design Manual.

8. Appendix A: Calculations should be performed with areas (in acres) using 2 decimal places. Many areas that are clearly different in the exhibits have the same value (0.1 acres comes to mind), which might lead to a significant error (for example, 0.05 to 0.149 acres = 0.1 even if the latter value is almost 3 times the former). Please update.

Areas associated with the project site location have been updated to use two decimal places. Other areas associated with offsite development to the south of the project site remain the same as the previously approved report titled, “Drainage Study for Laurel Heights” dated July 19, 2021.

9. Appendix A: User-specified runoff coefficient of 0.33 (Node 205 to 207) does not correspond with the value in Appendix C. Make appropriate adjustments in either A or C for all return periods.

The runoff coefficient in Appendix C has been revised to match that in Appendix A for Node 205 to 207.

10. Appendix A: Manning’s coefficient used is 0.013, while Section 3.1.1 uses 0.015.

Reconcile or explain the difference.

Section 3.1.1 of the report has been revised to state 0.013.

11. Appendix B: Hydraulic Analysis Report: Please provide a brief explanation at each subsection. It is difficult to follow what was done in terms of calculations. Also, ensure that the equations used are properly described in Section 3.1.2, and that there is a correspondence between equations in 3.1.2 and Appendix B equations.

These calculations have been moved to Appendix D and represent the inlet sizing for the specified Node number in the analysis.

12. Appendix B: Manning’s coefficient shown in calculations is 0.013, while Section 3.1.1 uses

0.015. Reconcile or explain the difference.

Section 3.1.1 of the report has been revised to state 0.013.

13. Percentage clogging for gutter analysis and curb opening is 0%, while it is 50% for grated inlets. REC agrees with the second but suggests a modification to the first assumption.

While curb openings have a tendency to clog less than grated inlets, assume at least a 25% clogging or justify a reference for 0% clog.

Based on the County of San Diego Hydraulic Design manual Section 2.2.2.3 for standard curb-openings the County states that they “tend to resist clogging”.

Furthermore, Tables 2-1 and 2-2 include footers for grate inlets to acknowledge weir length and opening area be reduced by 50%, but these footers are not used for Curb Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Openings. Assuming no clogging for standard inlets is then consistent with these equations.

14. Appendix C: “Basin 200/POC 2” (pre-project) – There is no POC 2. Post-project “Basin 1/POC” is mislabeled.

Appendix C has been updated and any reference to POC 2 has been removed.

15. Appendix C: Back-up for weighted C coefficient: A pervious C coefficient of 0.35 or 0.33 should not be used anywhere because there are no soils type D in the area analyzed.

Please change to 0.30 (the use of C other than 0.3 contradicts the exhibit provided in Appendix C regarding soil group). Correct all C coefficients impacted.

In the pre-project condition to the south of the project type-D soils are present. An updated hydrologic soil group map has been included to show the extents of the offsite area and the location of type-D soils.

16. Appendix C: Impervious and pervious tributary areas will change in C tables when areas are corrected to 2 decimal places.

17. Appendix C: Please correct the 0.14 value at the end of the Post-Project Table. It can also be removed, as it is not used in the model calculating peak flows.

This value has been removed.

18. Appendix C: Provide a brief explanation about the 5.6-acre area in the post-project C table, as it is not specified in the exhibits: add a note saying that it is the total of predevelopment areas x + y + …. that do not change with the development. Similarly with Area 6.3 acres.

A note has been added to Appendix C. These areas represent offsite areas that will remain the same in both the pre and the post project conditions.

19. Appendix D: Inlet Sizing Calculations: Identify Le and Ae used in the tables to verify the capacity. Also, check parenthesis in Q100 line for some of the tables (regarding Node 145). Calculations will change when areas are provided with 1 decimal place.

Ae and Le are associated with the typical sizes of the grate inlets minus the width of the bars times a debris factor of 50%. These values are now shown in the calculation in Appendix D.

20. Appendix E: Preliminary Storm Drain Size (pdf page 134): It is not clear if the full flow capacity was used for minimum pipe calculation or the maximum channel capacity was used (the former is some 7.5% smaller than the latter). Please add an explanation. Also, provide a pipe number in the table and an overall scheme of the pipes in this section for identification purposes. Identify the nodes for the pipes as well.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25
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The Q100 with sizing factor is the Q that is used for storm drain sizing. A column has been added to correlate the table to the storm drain numbers on the plans sheets. The plan sheets have also been included.

21. Appendix E: Preliminary Storm Drain Size (pdf page 134): Inconsistencies in the design are discovered for large pipes: for example, for Q = 20. The pipe is 30” for 1% but 24” for 2%. Which one was used? Also, for Q = 28 cfs the pipe selected is not sufficient for the minimum size calculation provided. Please correct this issue.

This table has been clarified. Wherever possible, the design of the system has tried to incorporate the unmitigated flows (20cfs) from the upstream Laurel Heights project. However, the release of unmitigated flows from the Laurel Heights project would be in an emergency overflow condition. In the typical case, it is anticipated that the mitigated flows (6.9 cfs) from Laurel Heights will be tributary to our site. Per Comment 26 below, using the mitigated flows we find the proposed system has adequate conveyance.

The bypass storm drain has been designed to convey unmitigated flows (20 cfs) in a 24-in storm drain flowing at 2%. The system ties into an existing 24-in storm drain within Mission Gorge Road and to avoid telescoping, it cannot be upsized. Based on a meeting with the City Engineer at the outset of the project (7/22/2024), it was agreed upon that offsite storm drain would not need to be upsized. In the case that the downstream system does not have capacity, flows will pond up in the proposed biofiltration basin and eventually overtop into Mission Gorge Road. Detailed overflow calculations are provided in Appendix F.

22. Map Pocket, Pre-Development: Add delineation of area at Node 230 so that pre and postdevelopment areas there are in agreement (in other words, a magenta line along the southerly property line is missing).

A delineation line has been added to the pre-project map. Pre-project and Postproject delineations are now consistent.

23. Map Pocket, Pre-Development: Include the longest water-path in the map for upstream Basin 100.

Flow paths have been included in the exhibit.

24. Map Pocket, Pre-Development: At nodes 230 & 290, clarify what “Pre-Mitigated” means in relation to this development or revise. No mitigation is proposed for this development and the Q is lower than the post-project condition.

The upstream project site, south of the project area has both undetained and detained (mitigated) flows. For the design of Aubrey Glen, the undetained flows have been used as a conservative measure and the mitigated flows previously shown on the pre-project exhibit have been removed as it is not used as part of the proposed design.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25
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ii.2. Drainage Study & Tentative Map Comments

25. The proposed 24” pipe within Mission Gorge Road is proposed to be pressurized (between nodes 266 to 290). Per section 4.F. of Drainage Design Criteria within The City of Santee Public Works Standards, public storm drain pipes cannot be pressurized.

Based on the comment below, we find that using the mitigated flow (6.9 cfs) from the Laurel Heights project that the capacity of the system from node 266 to 290 is sufficient and will not be pressurized.

However, in an emergency flow condition, it is anticipated that the storm drain from node 266 to 290 will be pressurized. In the City of Santee’s Public Works Standards Section 4.F states that conduits “should be designed to flow fee of pressure heads”, however, it also acknowledges there are cases where “it is necessary to design for a pressure head in a system and it is approved, pressure pipe and appurtenance shall be used.” Given the existing storm drain is 24-inches, it is anticipated that this will be a case where it will be necessary to design for pressure head for the emergency condition.

26. Utilizing the unmitigated Q100 may be overly conservative and show flooding onsite. To demonstrate the storm drain pipe wouldn’t be pressurized, HGL Calculations may be performed using the mitigated peak 100-year flowrates from Laurel Heights if needed, however, ensure there is a path for emergency overflow to Mission Gorge Road.

Wherever possible, we have designed for unmitigated flows (20cfs) from Laurel Heights, however it is anticipated that this will only occur in emergency overflow conditions. Using the mitigated flow from Laurel Heights we find free-flow conditions in the existing storm drain. This is consistent with the City of Santee Master Drainage Study, showing the existing storm drains have sufficient capacity for existing flows, which, based on our analysis are not increasing in the postproject condition. See a snip of the Master Drainage Study below:

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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27. Provide calculations for the Type ‘F’ catch basin demonstrating that:
o (a) It can capture the entire unmitigated peak 100-year flowrate from Laurel Heights without overtopping the retaining wall (no clogging). o (b) It can capture the entire mitigated peak 100-year flowrate with a 50% clogging factor, whilst providing adequate freeboard. The “offsite storm drain detail” on sheet 3 of the TM shows rim elevation above the wall. Revise if necessary.

Appendix F has been added to show emergency conveyance on the upstream side of the project where the undetained Q100 (20.0 cfs) can be conveyed without clogging and without over topping the wall. Additionally, another Type-F has been added to the west of the upstream project’s outfall in case clogging occurs. The brow-ditch has been sized to convey 50% of the Q100 (10cfs).

28. There is an inadequate path for runoff at the Type ‘F’ catch basin to be safely conveyed from the site in the event the inlet is clogged. As designed, it would overtop the 10’ wall and flow into the development. Consider either the brow ditch to Laurel Heights as an emergency path, or an additional pipe to the east or to the west of the development. In other words, demonstrate there is a path for overflow in the event the Type ‘F’ inlet becomes partially clogged. Can the brow ditch flow line high points be lowered to convey flow west in an emergency condition? Revise the plans (including the detail on sheet 3) as necessary and provide a discussion within the Drainage Study.

See response to the comment above and refer to Appendix F.

29. The Type ‘F’ catch basin is located behind a 10 ft retaining wall on off-site property. Who will be responsible for the maintenance of this inlet? If it is the developer, provide a letter of permission from the Laurel Heights HOA and an adequate access easement for maintenance (to be granted prior to tentative map approval).

This inlet will be maintained by the HOA. A permission letter and access easement are currently being coordinated with the property to the south.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
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Revised: 3-21-25
1 1.0 INTRODUCTION

1.1 Project Description
This drainage study presents hydrologic and hydraulic analyses for the proposed Townsend MultiFamily Project (herein referred to as the “project”). The project is located within the City of Santee, approximately 230 feet south of the intersection of Mission Gorge Road and Aubrey Glen. (See Figure 1, Vicinity Map). The proposed project is a new development project that proposes the construction of 52 three-story townhomes with a 5,000 SF common area. The project’s existing condition currently consists of a concrete parking lot with an existing building, which will be demolished for construction.

1.2 Drainage Characteristics
Pre-Project Condition
The pre-project site drains generally in the north direction to a single point of comparison (POC1) located on the northeast side of the property along Mission Gorge Road. The project site is situated in one major basin boundary, Basin 200. Offsite flows adjacent to the project site are represented by Basin 100 and a portion of Basin 200 that drains the existing Laurel Heights development. Basin 100 begins south of the project site and drains north to a cobble lined swale.

Flows from the swale discharge through a curb opening onto Aubrey Glen Drive, then are collected by a v-gutter and conveyed north to an existing curb inlet on Mission Gorge Road. Basin 200 also begins on the south of the site and drains north to a detention vault and then to a water quality basin. Flows are discharged from the basin onto the Townsend Multi-Family project site, then collected by an existing brow ditch and conveyed to Mission Gorge Road. Flows from Basin 100 and Basin 200 confluence on Mission Gorge Road prior to entering the existing storm drain system and ultimately discharging into the San Diego River.

Post-Project Condition
Drainage patterns for the proposed condition will remain similar to drainage patterns in the preproject condition. In the post-project condition, the project area is also found in Basin 200. Offsite flows are found in Basin 100 and on a portion Basin 200 that drains the existing Laurel Heights development. No improvements are proposed in Basin 100; therefore Basin 100 will remain in the same condition as the pre-project. Regarding Basin 200, flows from the adjacent sites south of the project are collected by a proposed clean water line storm drain system and conveyed north Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
2 to the edge of the property boundary. The clean water line is intended to route offsite flows through the site which are already treated via the water quality basin south of the project. To ensure appropriate sizing, the clean water line is sized and designed for the unmitigated 100-year storm event rather than the mitigated 100-year storm event. Flows from the south are captured in a proposed type-F catch basin on the south property edge of the site and routed to the clean water line that flows north to the property frontage.

Drainage onsite of the Townsend Multi-Family project will be collected by curb inlets and grate inlets and conveyed by a proposed dirty water storm drain system to the northern edge of the property boundary. The dirty water line is treated via proposed modular wetland system (MWS), then confluenced with the clean water line prior to discharge from the site. Additional drainage along the northern portion of the Townsend Multi-Family site is collected by a grate inlet and treated by a biofiltration basin, then joined with flows discharging the site to Mission Gorge Road.

Flows from Basin 100 and Basin 200 confluence in a proposed cleanout on Mission Gorge Road prior to ultimately discharging to the San Diego River. In the event of an emergency overflow, drainage from the project site will overtop the frontage of the site and drain onto Mission Gorge Road.

1.3 Hydrology, Hydraulics, and Detention
Hydrology, hydraulics, and detention are discussed in Sections 2.0, 3.0, and 4.0 respectively of this report.

1.4 Water Quality
Post-project storm water runoff will be managed via a combination of a biofiltration basin and a modular wetland system, designed pursuant to the guidelines from the City of Santee BMP Design Manual, dated February 2016. The PDP SWQMP specific to the Townsend Multi-Family project is dated August 30, 2024 (or any revision made thereafter) and prepared by RICK.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
3 Figure 1: Vicinity Map
Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
4 2.0 HYDROLOGY
The hydrologic conditions were analyzed in accordance with the June 2003 San Diego County Hydrology Manual.

2.1 Methodology
To determine the peak flows at the point of comparison (POC) identified on the provided drainage study exhibits, Advance Engineering Software (AES) 2014 Rational Method computer software version 21.0 was used. The hydrologic model was developed by first dividing each major drainage basin into several subareas. The delineation of each subarea was determined so that area within each subarea is comprised of similar hydrologic features, including topography, land use, and storm drain conveyance system (e.g., urban open channel, pipe, natural open channel, etc.).

Nodes were identified at the upstream and downstream extents of each subarea, and subarea hydrologic data was determined, such as the land use(s) and drainage facility geometry, elevations, and lengths. Hydrologic backup information is included in Appendix C and AES output is provided in Appendix A and B for pre and post-project conditions respectively.

Next, the hydrologic data describing each subarea were incorporated into the AES software in order to create a node-link model for each watershed. For each subarea the AES software performs calculations for the specific hydrologic process occurring in the subarea. There are 15 different hydrologic processes programmed into the software, and each process is assigned a code number that is presented on the model results. The AES Rational Method computer software hydrologic processes code numbers are described in Table 1.

Table 1: Subarea Hydrologic Processes (Codes)
Code Subarea Type
Code 1 Confluence analysis at a node
Code 2 Initial subarea analysis
Code 3 Pipe flow travel time (computer-estimated pipe sizes) Code 4 Pipe flow travel time (user-specified pipe size) Code 5 Trapezoidal channel travel time
Code 6 Street flow analysis through a subarea
Code 7 User-specified information at a node
Code 8 Addition of the subarea runoff to mainline
Code 9 V-Gutter flow through subarea
Code 10 Copy mainstream data onto a memory bank
Code 11 Confluence a memory bank with the mainstream memory Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
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Revised: 3-21-25
5 Table 1: Subarea Hydrologic Processes (Codes)
Code Subarea Type
Code 12 Clear a memory bank
Code 13 Clear the mainstream memory
Code 14 Copy a memory bank onto the mainstream memory
Code 15 Hydrologic data bank storage functions
The hydrologic conditions were analyzed in accordance with the County of San Diego’s design criteria as follows:

San Diego County Hydrology Manual, June 2003:

Design Storm: 100-year. 6-hour (for storm drain systems) Runoff Coefficients: Weighted Runoff Coefficients (1)
0% Impervious Areas C=0.30 for Type-C soils
C=0.35 for Type-D soils
100% Impervious Areas C=0.9
Soil Type (Conservatively Applied) “D”
Design Storm Precipitation2 100-year, 6-hour, P=2.4 inches 50-year, 6-hour, P=2.3 inches
10-year, 6-hour, P=1.7 inches
Rainfall Intensity: Based on time-intensity criteria per Section 3.0 of the County Hydrology Manual (San Diego County,
2003)
(1) Utilized to calculate composite ‘C’ values based on percent impervious. (2) Isopluvial maps provided in Appendix C.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
6 2.2 Hydrologic Results
Rational Method Results
The 100-, 50-, and 10-year peak flow rates for the Pre- and Post-Project conditions are summarized in Table 2.1 below.

Table 2.1: Summary of Hydrologic Conditions
Drainage
Basin ID POC
Return
Period
(years)
Project
Condition
Tributary
Area (ac)
Time Of
Concentration
(minutes)
Q
(cfs)
100 & 200 1
10 Pre-Project
(Unmitigated) 14.59

8.85 30.30
Post-Project
(Unmitigated) 9.11 24.14
50 Pre-Project
(Unmitigated) 14.59

8.63 41.66
Post-Project
(Unmitigated) 8.83 32.53
100
Pre-Project
(Unmitigated) 14.59

8.59 43.62
Post-Project
(Unmitigated) 8.81 33.90
100
Pre-Project
(Mitigated) 14.59

17.14 22.88
Post-Project
(Mitigated) 17.37 22.67
Based on the Rational Method result and a comparison of the pre-and post-project POC 1, it can be observed that the peak discharge rate to POC 1 has decreased. Comparing the existing condition of the site and the proposed condition, there’s a decrease in impervious areas as the site changes from an industrial site with a concrete parking lot to a multifamily residential development with landscaped areas. The decrease in impervious area results in a decrease of runoff peak flow. Additionally, referring to the Santee Master Drainage Plan published in 2023 by RICK, it’s noted that the existing storm drain infrastructure at the project site is sized appropriately and not deficient. Due to the decrease in peak flows and the existing storm drain infrastructure in the project area, it can be concluded that detention is not required for this project.

Ultimately, the existing and the proposed condition flows from the site and drain in north direction to the existing storm drain system on Mission Gorge Road. Flows from Mission Gorge are then conveyed and discharged into the San Diego River. Refer to Appendix A and Appendix B of this report for pre- and post-project Rational Method calculations respectively and Appendix C for Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
7 backup documentation. The location of the POC, drainage boundaries, flow patterns, and pervious/impervious areas can be found on the work maps titled, “Pre-project Drainage Study Map for Townsend Multi-Family” located in Map Pocket 1 and “Post-project Drainage Study Map for Townsend Multi-Family,” located in Map Pocket 2.

3.0 HYDRAULICS

3.1 Hydraulic Methodology and Criteria
The 100-year post-project peak flow rates determined using the Modified Rational Method was used to size the on-site storm drain system. In addition, hydraulic analyses regarding inlet sizing calculations are included in Appendix D.

3.1.1 Storm Drain Sizing
Storm drain pipe sizes were determined based on a normal depth calculation to verify storm drain capacity based on Manning’s equation.

Q= (1.486/n) A R 2/3 S ½
Where:

Q = Discharge (cfs)
n = Manning’s roughness coefficient
A = Cross-sectional Area of flow (sq. ft.)
R = Hydraulic radius (ft.) (where hydraulic radius is defined as the cross-section area of flow divided by the wetted perimeter, R= A/P)
S = Slope of pipe (ft./ft.)
The Manning’s roughness coefficient “n” of 0.013 was used for the hydraulic calculations. This value is typically used for reinforced concrete pipe (RCP), polyvinyl chloride (PVC), and highdensity polyethylene pipe (HDPE). The pipe sizes were evaluated based on the Rational Method flow rates with a 30% “bump up” sizing factor to account for hydraulic losses within the system.

Please refer to Appendix E for the storm drain sizes. The AES rational method results for the postproject condition are located in Appendix B of this report, which may be referenced for further information concerning pipe flow.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
8 3.1.2 Inlet Design
Inlet design calculations were completed using a computer program based on the following equations for inlets on a grade and inlets in a sump:

Type B Inlets on a Grade
Q = 0.7 L (a + y)3/2
Where: y = depth of flow approaching the curb inlet, in feet (ft) a = depth of depression of curb at inlet, in feet (ft)
L = length of clear opening of inlet for total interception, in feet (ft) Q = interception capacity of the curb inlet, in cubic feet per second (cfs) Type B Inlets in a Sump at Shallow Flow Depths (Weir)
Q = Cw Lw d
3/2
Where: Q = inlet capacity, in cubic feet per second (cfs) Cw = weir discharge coefficient (see Table 2-1 of County of San Diego Hydraulic Design Manual)
Lw = weir length, in feet (ft)
d = flow depth, in feet (ft)
Type B Inlets in a Sump at Higher Flow Depths (Orifice) Q = 0.67 h L (2 g do) 1/2
Where: Q = inlet capacity, in cubic feet per second (cfs) h = curb opening height, in feet (ft)
L = curb opening length, in feet (ft)
g = gravitational acceleration, in feet squared per second (ft2 / sec) do = effective depth of flow at curb face, in feet (ft) Inlet Results
Inlet locations have been identified for this project. Inlets are sized for the 100-year, 6-hour storm event. Each inlet is sized to provide 100% capture of the flow draining to the inlet. The inlet design calculations along with back up information is presented in Appendix D. Refer to the drainage study map provided in Map Pocket 2 for the location of each inlet.

Prepared By: SFR:JS:vs/C19500/WR/Reports/DrnStudy/4thSub/19964.007 RICK – Water Resources Division 8-30-24
11-7-24
1-29-25
Revised: 3-21-25
9 4.0 DETENTION ANALYSES
No detention analysis was conducted or required for this project. Based on the Rational Method results and a comparison of the pre-and post-project POC, it was observed that the peak discharge rate to POC 1 has decreased. When comparing the existing condition of the site and the proposed condition, there’s a decrease in impervious area as the site changes from an industrial site with a concrete parking lot to a multifamily residential development with landscaped areas. The decrease in impervious area results in a decrease of runoff peak flow. Additionally, when referring to the Santee Master Drainage Plan published in 2023 by RICK, its noted that the existing storm drain infrastructure at the project site is sized appropriately and not deficient. Since the existing storm drain infrastructure is appropriately sized, no detention is required.

5.0 CONCLUSION
This drainage study presents the hydrologic and hydraulic analyses for the Townsend MultiFamily project. The project is a new development project located in the City of Santee. The postproject condition peak discharge rates were determined using the Rational Method based on the hydrologic methodology and criteria described in the County of San Diego Hydrology Manual, dated June 2003.

Post-project flows will be treated per the City of Santee’s BMP Design Manual, dated February 2016. For more information on water quality sizing, please refer to the separate report titled, “Priority Development Project Storm Water Quality Management Plan (PDP SWQMP) for Townsend Multi-Family,” dated August 30th, 2024 or any revisions thereafter, and prepared by RICK.

Based on the Rational Method result and a comparison of the pre- and post-project POC, it can be observed that the post-project peak discharge rate to POC 1 has decreased. Therefore, it is anticipated that there will be no adverse effects to downstream drainage characteristics/systems as a result of the project.

APPENDIX A
Modified Rational Method Output
[Pre-project]
____________________________________________________________________________ ****************************************************************************

RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE
Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT
2003,1985,1981 HYDROLOGY MANUAL
(c) Copyright 1982-2014 Advanced Engineering Software (aes) Ver. 21.0 Release Date: 06/01/2014 License ID 1261
Analysis prepared by:

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * (J-19964) AUBREY GLEN *
* UNDETAINED FLOWS FROM LAUREL HEIGHTS *
* PRE-PROJECT CONDITION: 10-YR, 6-HR STORM EVENT *
************************************************************************** FILE NAME: AG10PREU.RAT
TIME/DATE OF STUDY: 14:59 03/20/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 10.00
6-HOUR DURATION PRECIPITATION (INCHES) = 1.700
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n)
=== ===== ========= ================= ====== ===== ====== ===== ======= 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS:

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 100.00 TO NODE 102.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 704.00
DOWNSTREAM ELEVATION(FEET) = 694.00
ELEVATION DIFFERENCE(FEET) = 10.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267
WARNING: THE MAXIMUM OVERLAND FLOW SLOPE, 10.%, IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.872
SUBAREA RUNOFF(CFS) = 0.14
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.14
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 110.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 694.00 DOWNSTREAM(FEET) = 445.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 1323.00 CHANNEL SLOPE = 0.1882 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 5.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 5.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.376
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3800
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.92
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.11 AVERAGE FLOW DEPTH(FEET) = 0.06 TRAVEL TIME(MIN.) = 7.10 Tc(MIN.) = 13.36
SUBAREA AREA(ACRES) = 1.70 SUBAREA RUNOFF(CFS) = 1.53
AREA-AVERAGE RUNOFF COEFFICIENT = 0.378
TOTAL AREA(ACRES) = 1.8 PEAK FLOW RATE(CFS) = 1.62
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.08 FLOW VELOCITY(FEET/SEC.) = 3.79
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 1423.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 115.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 445.00 DOWNSTREAM(FEET) = 424.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 233.00 CHANNEL SLOPE = 0.0901 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.312
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.69
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.71 AVERAGE FLOW DEPTH(FEET) = 0.12 TRAVEL TIME(MIN.) = 0.58 Tc(MIN.) = 13.94
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.15
AREA-AVERAGE RUNOFF COEFFICIENT = 0.374
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 1.73
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.12 FLOW VELOCITY(FEET/SEC.) = 6.84
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 115.00 = 1656.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 115.00 TO NODE 120.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 420.00 DOWNSTREAM(FEET) = 400.00 FLOW LENGTH(FEET) = 161.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 3.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 11.01
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 1.73
PIPE TRAVEL TIME(MIN.) = 0.24 Tc(MIN.) = 14.19
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 1817.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 125.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 400.00 DOWNSTREAM(FEET) = 395.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0500 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.255
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.76
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 5.55 AVERAGE FLOW DEPTH(FEET) = 0.15 TRAVEL TIME(MIN.) = 0.30 Tc(MIN.) = 14.49
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.07
AREA-AVERAGE RUNOFF COEFFICIENT = 0.370
TOTAL AREA(ACRES) = 2.1 PEAK FLOW RATE(CFS) = 1.75
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.14 FLOW VELOCITY(FEET/SEC.) = 5.76
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 125.00 = 1917.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 125.00 TO NODE 130.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 387.00 DOWNSTREAM(FEET) = 381.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 150.00 CHANNEL SLOPE = 0.0400 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.209
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.79
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 5.26 AVERAGE FLOW DEPTH(FEET) = 0.16 TRAVEL TIME(MIN.) = 0.48 Tc(MIN.) = 14.96
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.07
AREA-AVERAGE RUNOFF COEFFICIENT = 0.367
TOTAL AREA(ACRES) = 2.2 PEAK FLOW RATE(CFS) = 1.78
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.16 FLOW VELOCITY(FEET/SEC.) = 5.32
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 130.00 = 2067.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 135.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 372.00 DOWNSTREAM(FEET) = 360.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 200.00 CHANNEL SLOPE = 0.0600 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.158
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.81
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.05 AVERAGE FLOW DEPTH(FEET) = 0.14 TRAVEL TIME(MIN.) = 0.55 Tc(MIN.) = 15.51
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.06
AREA-AVERAGE RUNOFF COEFFICIENT = 0.364
TOTAL AREA(ACRES) = 2.3 PEAK FLOW RATE(CFS) = 1.81
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.14 FLOW VELOCITY(FEET/SEC.) = 6.02
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 135.00 = 2267.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 135.00 TO NODE 150.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 357.00 DOWNSTREAM(FEET) = 354.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 70.00 CHANNEL SLOPE = 0.0429 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 2.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 1.50
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.127
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.84
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.32 AVERAGE FLOW DEPTH(FEET) = 0.23 TRAVEL TIME(MIN.) = 0.35 Tc(MIN.) = 15.86
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.06
AREA-AVERAGE RUNOFF COEFFICIENT = 0.361
TOTAL AREA(ACRES) = 2.4 PEAK FLOW RATE(CFS) = 1.84
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.23 FLOW VELOCITY(FEET/SEC.) = 3.33
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 2337.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.127
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5221
SUBAREA AREA(ACRES) = 2.30 SUBAREA RUNOFF(CFS) = 3.38
TOTAL AREA(ACRES) = 4.7 TOTAL RUNOFF(CFS) = 5.22
TC(MIN.) = 15.86
**************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 250.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 354.00 DOWNSTREAM ELEVATION(FEET) = 353.00 STREET LENGTH(FEET) = 65.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 20.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 15.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 5.31 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.34
HALFSTREET FLOOD WIDTH(FEET) = 10.54
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.32
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.46
STREET FLOW TRAVEL TIME(MIN.) = 0.25 Tc(MIN.) = 16.12
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.105
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.529
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.18
TOTAL AREA(ACRES) = 4.8 PEAK FLOW RATE(CFS) = 5.34
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.34 HALFSTREET FLOOD WIDTH(FEET) = 10.60 FLOW VELOCITY(FEET/SEC.) = 4.31 DEPTH*VELOCITY(FT*FT/SEC.) = 1.46 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 250.00 = 2402.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 250.00 TO NODE 250.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.105
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5471
SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) = 0.53
TOTAL AREA(ACRES) = 5.1 TOTAL RUNOFF(CFS) = 5.87
TC(MIN.) = 16.12
**************************************************************************** FLOW PROCESS FROM NODE 250.00 TO NODE 260.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 353.00 DOWNSTREAM ELEVATION(FEET) = 339.00 STREET LENGTH(FEET) = 400.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 24.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 19.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 6.21 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.32
HALFSTREET FLOOD WIDTH(FEET) = 9.49
AVERAGE FLOW VELOCITY(FEET/SEC.) = 6.10
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.93
STREET FLOW TRAVEL TIME(MIN.) = 1.09 Tc(MIN.) = 17.21
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.018
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.568
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 0.68
TOTAL AREA(ACRES) = 5.5 PEAK FLOW RATE(CFS) = 6.31
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.32 HALFSTREET FLOOD WIDTH(FEET) = 9.56
FLOW VELOCITY(FEET/SEC.) = 6.11 DEPTH*VELOCITY(FT*FT/SEC.) = 1.94 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 260.00 = 2802.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 260.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.018
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5951
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 1.02
TOTAL AREA(ACRES) = 6.1 TOTAL RUNOFF(CFS) = 7.33
TC(MIN.) = 17.21
**************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 270.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 339.00 DOWNSTREAM ELEVATION(FEET) = 337.00 STREET LENGTH(FEET) = 230.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 7.49 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.40
HALFSTREET FLOOD WIDTH(FEET) = 13.71
AVERAGE FLOW VELOCITY(FEET/SEC.) = 3.75
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.50
STREET FLOW TRAVEL TIME(MIN.) = 1.02 Tc(MIN.) = 18.23
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 1.944
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.603
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.33
TOTAL AREA(ACRES) = 6.3 PEAK FLOW RATE(CFS) = 7.39
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.40 HALFSTREET FLOOD WIDTH(FEET) = 13.64 FLOW VELOCITY(FEET/SEC.) = 3.73 DEPTH*VELOCITY(FT*FT/SEC.) = 1.49 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 270.00 = 3032.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 18.23
RAINFALL INTENSITY(INCH/HR) = 1.94
TOTAL STREAM AREA(ACRES) = 6.30
PEAK FLOW RATE(CFS) AT CONFLUENCE = 7.39
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 425.00
DOWNSTREAM ELEVATION(FEET) = 417.00
ELEVATION DIFFERENCE(FEET) = 8.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.455
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 98.00
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.479
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.27
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.27
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 205.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 417.00 DOWNSTREAM ELEVATION(FEET) = 407.00 STREET LENGTH(FEET) = 300.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 13.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.018
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.80 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.18
HALFSTREET FLOOD WIDTH(FEET) = 2.65
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.38
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.78
STREET FLOW TRAVEL TIME(MIN.) = 1.14 Tc(MIN.) = 5.60
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.165
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.780
SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) = 1.05
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.30
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.21 HALFSTREET FLOOD WIDTH(FEET) = 4.51
FLOW VELOCITY(FEET/SEC.) = 4.29 DEPTH*VELOCITY(FT*FT/SEC.) = 0.90 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 205.00 = 400.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 205.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.165
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7320
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 1.75
TOTAL AREA(ACRES) = 1.0 TOTAL RUNOFF(CFS) = 3.05
TC(MIN.) = 5.60
**************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 207.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 403.00 DOWNSTREAM(FEET) = 400.00 FLOW LENGTH(FEET) = 60.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.4 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 9.00
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 3.05
PIPE TRAVEL TIME(MIN.) = 0.11 Tc(MIN.) = 5.71
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 207.00 = 460.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.113
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6955
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.14
TOTAL AREA(ACRES) = 1.1 TOTAL RUNOFF(CFS) = 3.15
TC(MIN.) = 5.71
**************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.113
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6946
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.57
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 3.71
TC(MIN.) = 5.71
**************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.113
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6933
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.42
TOTAL AREA(ACRES) = 1.8 TOTAL RUNOFF(CFS) = 5.13
TC(MIN.) = 5.71
**************************************************************************** FLOW PROCESS FROM NODE 207.00 TO NODE 210.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 400.00 DOWNSTREAM(FEET) = 386.00 FLOW LENGTH(FEET) = 170.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 12.49
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 5.13
PIPE TRAVEL TIME(MIN.) = 0.23 Tc(MIN.) = 5.93
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 210.00 = 630.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 208.00 TO NODE 210.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.011
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6925
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 1.66
TOTAL AREA(ACRES) = 2.4 TOTAL RUNOFF(CFS) = 6.67
TC(MIN.) = 5.93
**************************************************************************** FLOW PROCESS FROM NODE 209.00 TO NODE 210.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.011
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6918
SUBAREA AREA(ACRES) = 0.90 SUBAREA RUNOFF(CFS) = 2.49
TOTAL AREA(ACRES) = 3.3 TOTAL RUNOFF(CFS) = 9.16
TC(MIN.) = 5.93
**************************************************************************** FLOW PROCESS FROM NODE 210.00 TO NODE 215.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 386.00 DOWNSTREAM(FEET) = 374.00 FLOW LENGTH(FEET) = 140.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 14.90
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 9.16
PIPE TRAVEL TIME(MIN.) = 0.16 Tc(MIN.) = 6.09
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 215.00 = 770.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 212.00 TO NODE 215.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.944
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6916
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.36
TOTAL AREA(ACRES) = 3.8 TOTAL RUNOFF(CFS) = 10.36
TC(MIN.) = 6.09
**************************************************************************** FLOW PROCESS FROM NODE 215.00 TO NODE 220.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 374.00 DOWNSTREAM(FEET) = 372.00 FLOW LENGTH(FEET) = 10.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 5.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 20.37
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 10.36
PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 6.10
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 220.00 = 780.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 211.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.940
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6913
SUBAREA AREA(ACRES) = 0.90 SUBAREA RUNOFF(CFS) = 2.45
TOTAL AREA(ACRES) = 4.7 TOTAL RUNOFF(CFS) = 12.80
TC(MIN.) = 6.10
**************************************************************************** FLOW PROCESS FROM NODE 217.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.940
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6912
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 1.09
TOTAL AREA(ACRES) = 5.1 TOTAL RUNOFF(CFS) = 13.89
TC(MIN.) = 6.10
**************************************************************************** FLOW PROCESS FROM NODE 217.00 TO NODE 220.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 375.00 DOWNSTREAM(FEET) = 370.00 FLOW LENGTH(FEET) = 50.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 17.62
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 13.89
PIPE TRAVEL TIME(MIN.) = 0.05 Tc(MIN.) = 6.15
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 220.00 = 830.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 218.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.921
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7200
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6917
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.28
TOTAL AREA(ACRES) = 5.2 TOTAL RUNOFF(CFS) = 14.10
TC(MIN.) = 6.15
**************************************************************************** FLOW PROCESS FROM NODE 220.00 TO NODE 222.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 370.00 DOWNSTREAM(FEET) = 367.00 FLOW LENGTH(FEET) = 60.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 30.0 INCH PIPE IS 8.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 13.29
GIVEN PIPE DIAMETER(INCH) = 30.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 14.10
PIPE TRAVEL TIME(MIN.) = 0.08 Tc(MIN.) = 6.22
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 222.00 = 890.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 222.00 TO NODE 225.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 369.25 DOWNSTREAM(FEET) = 369.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0025 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 1.50
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.544
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 14.34
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.72 AVERAGE FLOW DEPTH(FEET) = 0.69 TRAVEL TIME(MIN.) = 0.97 Tc(MIN.) = 7.19
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 0.47
AREA-AVERAGE RUNOFF COEFFICIENT = 0.666
TOTAL AREA(ACRES) = 5.6 PEAK FLOW RATE(CFS) = 14.10
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.68 FLOW VELOCITY(FEET/SEC.) = 1.71
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 225.00 = 990.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 225.00 TO NODE 230.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 367.00 DOWNSTREAM(FEET) = 360.00 FLOW LENGTH(FEET) = 39.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 7.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 21.93
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 14.10
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.22
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 230.00 = 1029.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 270.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 337.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 704.00 CHANNEL SLOPE = 0.0327 CHANNEL BASE(FEET) = 3.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 5.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.168
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 17.44
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 8.78 AVERAGE FLOW DEPTH(FEET) = 0.45 TRAVEL TIME(MIN.) = 1.34 Tc(MIN.) = 8.55
SUBAREA AREA(ACRES) = 2.51 SUBAREA RUNOFF(CFS) = 6.68
AREA-AVERAGE RUNOFF COEFFICIENT = 0.720
TOTAL AREA(ACRES) = 8.1 PEAK FLOW RATE(CFS) = 18.49
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.47 FLOW VELOCITY(FEET/SEC.) = 8.92
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 270.00 = 1733.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 8.55
RAINFALL INTENSITY(INCH/HR) = 3.17
TOTAL STREAM AREA(ACRES) = 8.11
PEAK FLOW RATE(CFS) AT CONFLUENCE = 18.49
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 7.39 18.23 1.944 6.30
2 18.49 8.55 3.168 8.11

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 21.96 8.55 3.168
2 18.74 18.23 1.944
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 21.96 Tc(MIN.) = 8.55
TOTAL AREA(ACRES) = 14.4
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 270.00 = 3032.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 337.00 DOWNSTREAM ELEVATION(FEET) = 336.00 STREET LENGTH(FEET) = 94.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 22.11 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.53
HALFSTREET FLOOD WIDTH(FEET) = 21.59
AVERAGE FLOW VELOCITY(FEET/SEC.) = 5.27
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 2.79
STREET FLOW TRAVEL TIME(MIN.) = 0.30 Tc(MIN.) = 8.85
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.099
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.670
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.31
TOTAL AREA(ACRES) = 14.5 PEAK FLOW RATE(CFS) = 30.17
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.58 HALFSTREET FLOOD WIDTH(FEET) = 26.65 FLOW VELOCITY(FEET/SEC.) = 5.57 DEPTH*VELOCITY(FT*FT/SEC.) = 3.23 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 290.00 = 3126.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.099
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6702
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.13
TOTAL AREA(ACRES) = 14.6 TOTAL RUNOFF(CFS) = 30.30
TC(MIN.) = 8.85
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 14.6 TC(MIN.) = 8.85
PEAK FLOW RATE(CFS) = 30.30
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * (J-19964) AUBREY GLEN *
* UNDETAINED FLOWS FROM LAUREL HEIGHTS *
* PRE-PROJECT CONDITION: 50-YR, 6-HR STORM EVENT *
************************************************************************** FILE NAME: AG50PREU.RAT
TIME/DATE OF STUDY: 16:59 11/05/2024
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 50.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.300
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 704.00
DOWNSTREAM ELEVATION(FEET) = 694.00
ELEVATION DIFFERENCE(FEET) = 10.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267
WARNING: THE MAXIMUM OVERLAND FLOW SLOPE, 10.%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.239
SUBAREA RUNOFF(CFS) = 0.18
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.18
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 110.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 694.00 DOWNSTREAM(FEET) = 445.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 1323.00 CHANNEL SLOPE = 0.1882 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 5.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.317
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3800
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.31
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.41 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 6.46 Tc(MIN.) = 12.73
SUBAREA AREA(ACRES) = 1.70 SUBAREA RUNOFF(CFS) = 2.14
AREA-AVERAGE RUNOFF COEFFICIENT = 0.378
TOTAL AREA(ACRES) = 1.8 PEAK FLOW RATE(CFS) = 2.26
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 4.28
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 1423.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 115.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 445.00 DOWNSTREAM(FEET) = 424.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 233.00 CHANNEL SLOPE = 0.0901 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.232
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.37
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 7.45 AVERAGE FLOW DEPTH(FEET) = 0.15 TRAVEL TIME(MIN.) = 0.52 Tc(MIN.) = 13.25
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.21
AREA-AVERAGE RUNOFF COEFFICIENT = 0.374
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 2.41
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.15 FLOW VELOCITY(FEET/SEC.) = 7.60
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 115.00 = 1656.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 115.00 TO NODE 120.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 420.00 DOWNSTREAM(FEET) = 400.00 FLOW LENGTH(FEET) = 161.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 3.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 12.11
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 2.41
PIPE TRAVEL TIME(MIN.) = 0.22 Tc(MIN.) = 13.47
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 1817.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 125.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 400.00 DOWNSTREAM(FEET) = 395.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0500 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.158
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.46
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.34 AVERAGE FLOW DEPTH(FEET) = 0.18 TRAVEL TIME(MIN.) = 0.26 Tc(MIN.) = 13.73
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.09
AREA-AVERAGE RUNOFF COEFFICIENT = 0.370
TOTAL AREA(ACRES) = 2.1 PEAK FLOW RATE(CFS) = 2.45
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.18 FLOW VELOCITY(FEET/SEC.) = 6.32
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 125.00 = 1917.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 125.00 TO NODE 130.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 387.00 DOWNSTREAM(FEET) = 381.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 150.00 CHANNEL SLOPE = 0.0400 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.097
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.50
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 5.89 AVERAGE FLOW DEPTH(FEET) = 0.19 TRAVEL TIME(MIN.) = 0.42 Tc(MIN.) = 14.16
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.09
AREA-AVERAGE RUNOFF COEFFICIENT = 0.367
TOTAL AREA(ACRES) = 2.2 PEAK FLOW RATE(CFS) = 2.50
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.19 FLOW VELOCITY(FEET/SEC.) = 5.88
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 130.00 = 2067.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 135.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 372.00 DOWNSTREAM(FEET) = 360.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 200.00 CHANNEL SLOPE = 0.0600 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.030
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.54
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.87 AVERAGE FLOW DEPTH(FEET) = 0.17 TRAVEL TIME(MIN.) = 0.49 Tc(MIN.) = 14.65
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.09
AREA-AVERAGE RUNOFF COEFFICIENT = 0.364
TOTAL AREA(ACRES) = 2.3 PEAK FLOW RATE(CFS) = 2.54
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.17 FLOW VELOCITY(FEET/SEC.) = 6.84
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 135.00 = 2267.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 135.00 TO NODE 150.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 357.00 DOWNSTREAM(FEET) = 354.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 70.00 CHANNEL SLOPE = 0.0429 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 2.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 1.50
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.989
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.58
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.73 AVERAGE FLOW DEPTH(FEET) = 0.27 TRAVEL TIME(MIN.) = 0.31 Tc(MIN.) = 14.96
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.09
AREA-AVERAGE RUNOFF COEFFICIENT = 0.361
TOTAL AREA(ACRES) = 2.4 PEAK FLOW RATE(CFS) = 2.59
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.27 FLOW VELOCITY(FEET/SEC.) = 3.75
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 2337.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.989
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5221
SUBAREA AREA(ACRES) = 2.30 SUBAREA RUNOFF(CFS) = 4.74
TOTAL AREA(ACRES) = 4.7 TOTAL RUNOFF(CFS) = 7.33
TC(MIN.) = 14.96
**************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 250.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 354.00 DOWNSTREAM ELEVATION(FEET) = 353.00 STREET LENGTH(FEET) = 65.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 20.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 15.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 7.46 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.37
HALFSTREET FLOOD WIDTH(FEET) = 12.18
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.66
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.72
STREET FLOW TRAVEL TIME(MIN.) = 0.23 Tc(MIN.) = 15.19
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.959
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.529
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.25
TOTAL AREA(ACRES) = 4.8 PEAK FLOW RATE(CFS) = 7.51
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.37 HALFSTREET FLOOD WIDTH(FEET) = 12.24 FLOW VELOCITY(FEET/SEC.) = 4.65 DEPTH*VELOCITY(FT*FT/SEC.) = 1.72 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 250.00 = 2402.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 250.00 TO NODE 250.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.959
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5471
SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) = 0.75
TOTAL AREA(ACRES) = 5.1 TOTAL RUNOFF(CFS) = 8.26
TC(MIN.) = 15.19
**************************************************************************** FLOW PROCESS FROM NODE 250.00 TO NODE 260.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 353.00 DOWNSTREAM ELEVATION(FEET) = 339.00 STREET LENGTH(FEET) = 400.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 24.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 19.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 8.73 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.35
HALFSTREET FLOOD WIDTH(FEET) = 10.97
AVERAGE FLOW VELOCITY(FEET/SEC.) = 6.60
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 2.28
STREET FLOW TRAVEL TIME(MIN.) = 1.01 Tc(MIN.) = 16.20
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.839
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.568
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 0.95
TOTAL AREA(ACRES) = 5.5 PEAK FLOW RATE(CFS) = 8.87
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.35 HALFSTREET FLOOD WIDTH(FEET) = 11.05 FLOW VELOCITY(FEET/SEC.) = 6.63 DEPTH*VELOCITY(FT*FT/SEC.) = 2.30 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 260.00 = 2802.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 260.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.839
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5951
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 1.43
TOTAL AREA(ACRES) = 6.1 TOTAL RUNOFF(CFS) = 10.31
TC(MIN.) = 16.20
**************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 270.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 339.00 DOWNSTREAM ELEVATION(FEET) = 337.00 STREET LENGTH(FEET) = 230.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 10.54 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.44
HALFSTREET FLOOD WIDTH(FEET) = 15.73
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.06
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.79
STREET FLOW TRAVEL TIME(MIN.) = 0.94 Tc(MIN.) = 17.14
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.737
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.603
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.46
TOTAL AREA(ACRES) = 6.3 PEAK FLOW RATE(CFS) = 10.40
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.44 HALFSTREET FLOOD WIDTH(FEET) = 15.59 FLOW VELOCITY(FEET/SEC.) = 4.08 DEPTH*VELOCITY(FT*FT/SEC.) = 1.79 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 270.00 = 3032.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 17.14
RAINFALL INTENSITY(INCH/HR) = 2.74
TOTAL STREAM AREA(ACRES) = 6.30
PEAK FLOW RATE(CFS) AT CONFLUENCE = 10.40
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 425.00
DOWNSTREAM ELEVATION(FEET) = 417.00
ELEVATION DIFFERENCE(FEET) = 8.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.455
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 98.00
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.060
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.36
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.36
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 205.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 417.00 DOWNSTREAM ELEVATION(FEET) = 407.00 STREET LENGTH(FEET) = 300.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 13.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.018
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.07 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.20
HALFSTREET FLOOD WIDTH(FEET) = 3.85
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.84
STREET FLOW TRAVEL TIME(MIN.) = 1.18 Tc(MIN.) = 5.64
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.607
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.780
SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) = 1.41
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.75
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.23 HALFSTREET FLOOD WIDTH(FEET) = 5.46
FLOW VELOCITY(FEET/SEC.) = 4.50 DEPTH*VELOCITY(FT*FT/SEC.) = 1.02 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 205.00 = 400.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 205.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.607
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7320
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 2.35
TOTAL AREA(ACRES) = 1.0 TOTAL RUNOFF(CFS) = 4.10
TC(MIN.) = 5.64
**************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 207.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 403.00 DOWNSTREAM(FEET) = 400.00 FLOW LENGTH(FEET) = 60.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 9.81
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 4.10
PIPE TRAVEL TIME(MIN.) = 0.10 Tc(MIN.) = 5.74
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 207.00 = 460.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.543
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6955
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.18
TOTAL AREA(ACRES) = 1.1 TOTAL RUNOFF(CFS) = 4.24
TC(MIN.) = 5.74
**************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.543
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6946
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.76
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 5.00
TC(MIN.) = 5.74
**************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.543
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6933
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.91
TOTAL AREA(ACRES) = 1.8 TOTAL RUNOFF(CFS) = 6.92
TC(MIN.) = 5.74
**************************************************************************** FLOW PROCESS FROM NODE 207.00 TO NODE 210.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 400.00 DOWNSTREAM(FEET) = 386.00 FLOW LENGTH(FEET) = 170.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 13.58
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 6.92
PIPE TRAVEL TIME(MIN.) = 0.21 Tc(MIN.) = 5.95
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 210.00 = 630.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 208.00 TO NODE 210.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.417
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6925
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 2.24
TOTAL AREA(ACRES) = 2.4 TOTAL RUNOFF(CFS) = 9.00
TC(MIN.) = 5.95
**************************************************************************** FLOW PROCESS FROM NODE 209.00 TO NODE 210.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.417
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6918
SUBAREA AREA(ACRES) = 0.90 SUBAREA RUNOFF(CFS) = 3.36
TOTAL AREA(ACRES) = 3.3 TOTAL RUNOFF(CFS) = 12.37
TC(MIN.) = 5.95
**************************************************************************** FLOW PROCESS FROM NODE 210.00 TO NODE 215.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 386.00 DOWNSTREAM(FEET) = 374.00 FLOW LENGTH(FEET) = 140.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 16.15
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 12.37
PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 6.09
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 215.00 = 770.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 212.00 TO NODE 215.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.333
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6916
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.84
TOTAL AREA(ACRES) = 3.8 TOTAL RUNOFF(CFS) = 14.02
TC(MIN.) = 6.09
**************************************************************************** FLOW PROCESS FROM NODE 215.00 TO NODE 220.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 374.00 DOWNSTREAM(FEET) = 372.00 FLOW LENGTH(FEET) = 10.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 6.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 22.22
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 14.02
PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 6.10
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 220.00 = 780.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 211.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.329
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6913
SUBAREA AREA(ACRES) = 0.90 SUBAREA RUNOFF(CFS) = 3.31
TOTAL AREA(ACRES) = 4.7 TOTAL RUNOFF(CFS) = 17.31
TC(MIN.) = 6.10
**************************************************************************** FLOW PROCESS FROM NODE 217.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.329
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6912
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 1.47
TOTAL AREA(ACRES) = 5.1 TOTAL RUNOFF(CFS) = 18.79
TC(MIN.) = 6.10
**************************************************************************** FLOW PROCESS FROM NODE 217.00 TO NODE 220.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 375.00 DOWNSTREAM(FEET) = 370.00 FLOW LENGTH(FEET) = 50.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 9.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 19.00
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 18.79
PIPE TRAVEL TIME(MIN.) = 0.04 Tc(MIN.) = 6.15
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 220.00 = 830.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 218.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.305
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7200
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6917
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.38
TOTAL AREA(ACRES) = 5.2 TOTAL RUNOFF(CFS) = 19.08
TC(MIN.) = 6.15
**************************************************************************** FLOW PROCESS FROM NODE 220.00 TO NODE 222.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 370.00 DOWNSTREAM(FEET) = 367.00 FLOW LENGTH(FEET) = 60.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 30.0 INCH PIPE IS 9.4 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 14.48
GIVEN PIPE DIAMETER(INCH) = 30.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.08
PIPE TRAVEL TIME(MIN.) = 0.07 Tc(MIN.) = 6.22
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 222.00 = 890.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 222.00 TO NODE 225.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 369.25 DOWNSTREAM(FEET) = 369.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0025 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 1.50
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.837
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 19.40
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.90 AVERAGE FLOW DEPTH(FEET) = 0.82 TRAVEL TIME(MIN.) = 0.88 Tc(MIN.) = 7.09
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 0.64
AREA-AVERAGE RUNOFF COEFFICIENT = 0.666
TOTAL AREA(ACRES) = 5.6 PEAK FLOW RATE(CFS) = 19.08
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.81 FLOW VELOCITY(FEET/SEC.) = 1.89
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 225.00 = 990.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 225.00 TO NODE 230.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 367.00 DOWNSTREAM(FEET) = 360.00 FLOW LENGTH(FEET) = 39.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.4 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 23.75
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.08
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.12
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 230.00 = 1029.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 270.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 337.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 704.00 CHANNEL SLOPE = 0.0327 CHANNEL BASE(FEET) = 3.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.352
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 23.67
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 9.51 AVERAGE FLOW DEPTH(FEET) = 0.54 TRAVEL TIME(MIN.) = 1.23 Tc(MIN.) = 8.35
SUBAREA AREA(ACRES) = 2.51 SUBAREA RUNOFF(CFS) = 9.18
AREA-AVERAGE RUNOFF COEFFICIENT = 0.720
TOTAL AREA(ACRES) = 8.1 PEAK FLOW RATE(CFS) = 25.41
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.56 FLOW VELOCITY(FEET/SEC.) = 9.70
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 270.00 = 1733.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 8.35
RAINFALL INTENSITY(INCH/HR) = 4.35
TOTAL STREAM AREA(ACRES) = 8.11
PEAK FLOW RATE(CFS) AT CONFLUENCE = 25.41
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 10.40 17.14 2.737 6.30
2 25.41 8.35 4.352 8.11

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 30.47 8.35 4.352
2 26.37 17.14 2.737
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 30.47 Tc(MIN.) = 8.35
TOTAL AREA(ACRES) = 14.4
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 270.00 = 3032.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 337.00 DOWNSTREAM ELEVATION(FEET) = 336.00 STREET LENGTH(FEET) = 94.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 30.69 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.58
HALFSTREET FLOOD WIDTH(FEET) = 26.94
AVERAGE FLOW VELOCITY(FEET/SEC.) = 5.59
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 3.25
STREET FLOW TRAVEL TIME(MIN.) = 0.28 Tc(MIN.) = 8.63
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.261
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.670
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.43
TOTAL AREA(ACRES) = 14.5 PEAK FLOW RATE(CFS) = 41.48
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.64 HALFSTREET FLOOD WIDTH(FEET) = 32.43 FLOW VELOCITY(FEET/SEC.) = 5.82 DEPTH*VELOCITY(FT*FT/SEC.) = 3.71 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 290.00 = 3126.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.261
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6702
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.18
TOTAL AREA(ACRES) = 14.6 TOTAL RUNOFF(CFS) = 41.66
TC(MIN.) = 8.63
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 14.6 TC(MIN.) = 8.63
PEAK FLOW RATE(CFS) = 41.66
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * (J-19964) AUBREY GLEN *
* UNDETAINED FLOWS FROM LAUREL HEIGHTS *
* PRE-PROJECT CONDITION: 100-YR, 6-HR STORM EVENT *
************************************************************************** FILE NAME: AG1HPRE.RAT
TIME/DATE OF STUDY: 16:08 11/05/2024
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.400
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n)
=== ===== ========= ================= ====== ===== ====== ===== ======= 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0312 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS:

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 704.00
DOWNSTREAM ELEVATION(FEET) = 694.00
ELEVATION DIFFERENCE(FEET) = 10.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267
WARNING: THE MAXIMUM OVERLAND FLOW SLOPE, 10.%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.466
SUBAREA RUNOFF(CFS) = 0.19
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.19
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 110.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 694.00 DOWNSTREAM(FEET) = 445.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 1323.00 CHANNEL SLOPE = 0.1882 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 5.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.500
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3800
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.35
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.53 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 6.24 Tc(MIN.) = 12.51
SUBAREA AREA(ACRES) = 1.70 SUBAREA RUNOFF(CFS) = 2.26
AREA-AVERAGE RUNOFF COEFFICIENT = 0.378
TOTAL AREA(ACRES) = 1.8 PEAK FLOW RATE(CFS) = 2.38
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 4.24
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 1423.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 115.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 445.00 DOWNSTREAM(FEET) = 424.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 233.00 CHANNEL SLOPE = 0.0901 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.412
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.50
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 7.75 AVERAGE FLOW DEPTH(FEET) = 0.15 TRAVEL TIME(MIN.) = 0.50 Tc(MIN.) = 13.01
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.23
AREA-AVERAGE RUNOFF COEFFICIENT = 0.374
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 2.55
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.15 FLOW VELOCITY(FEET/SEC.) = 7.92
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 115.00 = 1656.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 115.00 TO NODE 120.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 420.00 DOWNSTREAM(FEET) = 400.00 FLOW LENGTH(FEET) = 161.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 3.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 12.30
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 2.55
PIPE TRAVEL TIME(MIN.) = 0.22 Tc(MIN.) = 13.23
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 1817.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 125.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 400.00 DOWNSTREAM(FEET) = 395.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0500 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.334
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.60
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.39 AVERAGE FLOW DEPTH(FEET) = 0.19 TRAVEL TIME(MIN.) = 0.26 Tc(MIN.) = 13.49
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.10
AREA-AVERAGE RUNOFF COEFFICIENT = 0.370
TOTAL AREA(ACRES) = 2.1 PEAK FLOW RATE(CFS) = 2.59
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.18 FLOW VELOCITY(FEET/SEC.) = 6.59
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 125.00 = 1917.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 125.00 TO NODE 130.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 387.00 DOWNSTREAM(FEET) = 381.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 150.00 CHANNEL SLOPE = 0.0400 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.270
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.64
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.15 AVERAGE FLOW DEPTH(FEET) = 0.20 TRAVEL TIME(MIN.) = 0.41 Tc(MIN.) = 13.90
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.10
AREA-AVERAGE RUNOFF COEFFICIENT = 0.367
TOTAL AREA(ACRES) = 2.2 PEAK FLOW RATE(CFS) = 2.64
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.20 FLOW VELOCITY(FEET/SEC.) = 6.15
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 130.00 = 2067.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 135.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 372.00 DOWNSTREAM(FEET) = 360.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 200.00 CHANNEL SLOPE = 0.0600 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 1.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.199
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.69
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 6.92 AVERAGE FLOW DEPTH(FEET) = 0.18 TRAVEL TIME(MIN.) = 0.48 Tc(MIN.) = 14.38
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.10
AREA-AVERAGE RUNOFF COEFFICIENT = 0.364
TOTAL AREA(ACRES) = 2.3 PEAK FLOW RATE(CFS) = 2.68
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.18 FLOW VELOCITY(FEET/SEC.) = 6.89
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 135.00 = 2267.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 135.00 TO NODE 150.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 357.00 DOWNSTREAM(FEET) = 354.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 70.00 CHANNEL SLOPE = 0.0429 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 2.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 1.50
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.155
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.73
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.72 AVERAGE FLOW DEPTH(FEET) = 0.29 TRAVEL TIME(MIN.) = 0.31 Tc(MIN.) = 14.69
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.09
AREA-AVERAGE RUNOFF COEFFICIENT = 0.361
TOTAL AREA(ACRES) = 2.4 PEAK FLOW RATE(CFS) = 2.74
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.29 FLOW VELOCITY(FEET/SEC.) = 3.73
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 2337.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.155
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5221
SUBAREA AREA(ACRES) = 2.30 SUBAREA RUNOFF(CFS) = 5.01
TOTAL AREA(ACRES) = 4.7 TOTAL RUNOFF(CFS) = 7.74
TC(MIN.) = 14.69
**************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 250.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 354.00 DOWNSTREAM ELEVATION(FEET) = 353.00 STREET LENGTH(FEET) = 65.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 20.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 15.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 7.87 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.38
HALFSTREET FLOOD WIDTH(FEET) = 12.47
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.71
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.77
STREET FLOW TRAVEL TIME(MIN.) = 0.23 Tc(MIN.) = 14.92
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.124
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.529
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.26
TOTAL AREA(ACRES) = 4.8 PEAK FLOW RATE(CFS) = 7.93
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.38 HALFSTREET FLOOD WIDTH(FEET) = 12.47 FLOW VELOCITY(FEET/SEC.) = 4.74 DEPTH*VELOCITY(FT*FT/SEC.) = 1.78 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 250.00 = 2402.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 250.00 TO NODE 250.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.124
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5471
SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) = 0.79
TOTAL AREA(ACRES) = 5.1 TOTAL RUNOFF(CFS) = 8.71
TC(MIN.) = 14.92
**************************************************************************** FLOW PROCESS FROM NODE 250.00 TO NODE 260.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 353.00 DOWNSTREAM ELEVATION(FEET) = 339.00 STREET LENGTH(FEET) = 400.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 24.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 19.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 9.22 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.35
HALFSTREET FLOOD WIDTH(FEET) = 11.20
AVERAGE FLOW VELOCITY(FEET/SEC.) = 6.72
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 2.35
STREET FLOW TRAVEL TIME(MIN.) = 0.99 Tc(MIN.) = 15.91
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.997
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.568
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 1.01
TOTAL AREA(ACRES) = 5.5 PEAK FLOW RATE(CFS) = 9.37
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.35 HALFSTREET FLOOD WIDTH(FEET) = 11.27 FLOW VELOCITY(FEET/SEC.) = 6.75 DEPTH*VELOCITY(FT*FT/SEC.) = 2.37 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 260.00 = 2802.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 260.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.997
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5951
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 1.51
TOTAL AREA(ACRES) = 6.1 TOTAL RUNOFF(CFS) = 10.88
TC(MIN.) = 15.91
**************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 270.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 339.00 DOWNSTREAM ELEVATION(FEET) = 337.00 STREET LENGTH(FEET) = 230.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 11.12 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.45
HALFSTREET FLOOD WIDTH(FEET) = 16.02
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.14
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.85
STREET FLOW TRAVEL TIME(MIN.) = 0.93 Tc(MIN.) = 16.84
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.889
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.603
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.49
TOTAL AREA(ACRES) = 6.3 PEAK FLOW RATE(CFS) = 10.97
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.45 HALFSTREET FLOOD WIDTH(FEET) = 15.95 FLOW VELOCITY(FEET/SEC.) = 4.12 DEPTH*VELOCITY(FT*FT/SEC.) = 1.84 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 270.00 = 3032.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 16.84
RAINFALL INTENSITY(INCH/HR) = 2.89
TOTAL STREAM AREA(ACRES) = 6.30
PEAK FLOW RATE(CFS) AT CONFLUENCE = 10.97
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 425.00
DOWNSTREAM ELEVATION(FEET) = 417.00
ELEVATION DIFFERENCE(FEET) = 8.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.455
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 98.00
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.38
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.38
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 205.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 417.00 DOWNSTREAM ELEVATION(FEET) = 407.00 STREET LENGTH(FEET) = 300.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 13.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.018
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.12 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.20
HALFSTREET FLOOD WIDTH(FEET) = 3.96
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.27
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.17 Tc(MIN.) = 5.63
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.860
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.780
SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) = 1.48
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.83
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.23 HALFSTREET FLOOD WIDTH(FEET) = 5.56
FLOW VELOCITY(FEET/SEC.) = 4.59 DEPTH*VELOCITY(FT*FT/SEC.) = 1.05 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 205.00 = 400.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 205.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.860
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7320
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 2.46
TOTAL AREA(ACRES) = 1.0 TOTAL RUNOFF(CFS) = 4.29
TC(MIN.) = 5.63
**************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 207.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 403.00 DOWNSTREAM(FEET) = 400.00 FLOW LENGTH(FEET) = 60.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 9.93
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 4.29
PIPE TRAVEL TIME(MIN.) = 0.10 Tc(MIN.) = 5.73
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 207.00 = 460.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 205.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.793
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6955
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.19
TOTAL AREA(ACRES) = 1.1 TOTAL RUNOFF(CFS) = 4.43
TC(MIN.) = 5.73
**************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.793
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6946
SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.80
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 5.23
TC(MIN.) = 5.73
**************************************************************************** FLOW PROCESS FROM NODE 206.00 TO NODE 207.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.793
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6933
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 2.00
TOTAL AREA(ACRES) = 1.8 TOTAL RUNOFF(CFS) = 7.23
TC(MIN.) = 5.73
**************************************************************************** FLOW PROCESS FROM NODE 207.00 TO NODE 210.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 400.00 DOWNSTREAM(FEET) = 386.00 FLOW LENGTH(FEET) = 170.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 13.76
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 7.23
PIPE TRAVEL TIME(MIN.) = 0.21 Tc(MIN.) = 5.93
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 210.00 = 630.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 208.00 TO NODE 210.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.663
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6925
SUBAREA AREA(ACRES) = 0.60 SUBAREA RUNOFF(CFS) = 2.34
TOTAL AREA(ACRES) = 2.4 TOTAL RUNOFF(CFS) = 9.41
TC(MIN.) = 5.93
**************************************************************************** FLOW PROCESS FROM NODE 209.00 TO NODE 210.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.663
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6918
SUBAREA AREA(ACRES) = 0.90 SUBAREA RUNOFF(CFS) = 3.52
TOTAL AREA(ACRES) = 3.3 TOTAL RUNOFF(CFS) = 12.93
TC(MIN.) = 5.93
**************************************************************************** FLOW PROCESS FROM NODE 210.00 TO NODE 215.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 386.00 DOWNSTREAM(FEET) = 374.00 FLOW LENGTH(FEET) = 140.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 16.33
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 12.93
PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 6.08
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 215.00 = 770.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 212.00 TO NODE 215.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.576
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6916
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.92
TOTAL AREA(ACRES) = 3.8 TOTAL RUNOFF(CFS) = 14.65
TC(MIN.) = 6.08
**************************************************************************** FLOW PROCESS FROM NODE 215.00 TO NODE 220.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 374.00 DOWNSTREAM(FEET) = 372.00 FLOW LENGTH(FEET) = 10.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 6.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 22.51
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 14.65
PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 6.08
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 220.00 = 780.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 211.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.572
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6913
SUBAREA AREA(ACRES) = 0.90 SUBAREA RUNOFF(CFS) = 3.46
TOTAL AREA(ACRES) = 4.7 TOTAL RUNOFF(CFS) = 18.10
TC(MIN.) = 6.08
**************************************************************************** FLOW PROCESS FROM NODE 217.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.572
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6912
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 1.54
TOTAL AREA(ACRES) = 5.1 TOTAL RUNOFF(CFS) = 19.64
TC(MIN.) = 6.08
**************************************************************************** FLOW PROCESS FROM NODE 217.00 TO NODE 220.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 375.00 DOWNSTREAM(FEET) = 370.00 FLOW LENGTH(FEET) = 50.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 10.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 19.20
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.64
PIPE TRAVEL TIME(MIN.) = 0.04 Tc(MIN.) = 6.13
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 220.00 = 830.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 218.00 TO NODE 220.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.546
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7200
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6917
SUBAREA AREA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 5.2 TOTAL RUNOFF(CFS) = 19.95
TC(MIN.) = 6.13
**************************************************************************** FLOW PROCESS FROM NODE 220.00 TO NODE 222.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 370.00 DOWNSTREAM(FEET) = 367.00 FLOW LENGTH(FEET) = 60.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 30.0 INCH PIPE IS 9.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 14.66
GIVEN PIPE DIAMETER(INCH) = 30.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.95
PIPE TRAVEL TIME(MIN.) = 0.07 Tc(MIN.) = 6.20
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 222.00 = 890.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 222.00 TO NODE 225.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 369.25 DOWNSTREAM(FEET) = 369.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0025 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 1.50
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.061
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3300
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 20.28
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.92 AVERAGE FLOW DEPTH(FEET) = 0.84 TRAVEL TIME(MIN.) = 0.87 Tc(MIN.) = 7.06
SUBAREA AREA(ACRES) = 0.40 SUBAREA RUNOFF(CFS) = 0.67
AREA-AVERAGE RUNOFF COEFFICIENT = 0.666
TOTAL AREA(ACRES) = 5.6 PEAK FLOW RATE(CFS) = 19.95
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.83 FLOW VELOCITY(FEET/SEC.) = 1.91
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 225.00 = 990.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 225.00 TO NODE 230.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 367.00 DOWNSTREAM(FEET) = 360.00 FLOW LENGTH(FEET) = 39.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 24.03
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.95
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.09
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 230.00 = 1029.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 270.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 337.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 704.00 CHANNEL SLOPE = 0.0327 CHANNEL BASE(FEET) = 3.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.558
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 24.76
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 9.63 AVERAGE FLOW DEPTH(FEET) = 0.55 TRAVEL TIME(MIN.) = 1.22 Tc(MIN.) = 8.31
SUBAREA AREA(ACRES) = 2.51 SUBAREA RUNOFF(CFS) = 9.61
AREA-AVERAGE RUNOFF COEFFICIENT = 0.720
TOTAL AREA(ACRES) = 8.1 PEAK FLOW RATE(CFS) = 26.60
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.58 FLOW VELOCITY(FEET/SEC.) = 9.79
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 270.00 = 1733.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 8.31
RAINFALL INTENSITY(INCH/HR) = 4.56
TOTAL STREAM AREA(ACRES) = 8.11
PEAK FLOW RATE(CFS) AT CONFLUENCE = 26.60
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 10.97 16.84 2.889 6.30
2 26.60 8.31 4.558 8.11

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 32.02 8.31 4.558
2 27.84 16.84 2.889
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 32.02 Tc(MIN.) = 8.31
TOTAL AREA(ACRES) = 14.4
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 270.00 = 3032.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 337.00 DOWNSTREAM ELEVATION(FEET) = 336.00 STREET LENGTH(FEET) = 94.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 32.24 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.59
HALFSTREET FLOOD WIDTH(FEET) = 27.81
AVERAGE FLOW VELOCITY(FEET/SEC.) = 5.63
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 3.33
STREET FLOW TRAVEL TIME(MIN.) = 0.28 Tc(MIN.) = 8.59
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.462
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.670
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.45
TOTAL AREA(ACRES) = 14.5 PEAK FLOW RATE(CFS) = 43.44
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.65 HALFSTREET FLOOD WIDTH(FEET) = 33.30 FLOW VELOCITY(FEET/SEC.) = 5.86 DEPTH*VELOCITY(FT*FT/SEC.) = 3.79 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 290.00 = 3126.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.462
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6702
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.18
TOTAL AREA(ACRES) = 14.6 TOTAL RUNOFF(CFS) = 43.62
TC(MIN.) = 8.59
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 14.6 TC(MIN.) = 8.59
PEAK FLOW RATE(CFS) = 43.62
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * (J-19964) AUBREY GLEN *
* DETAINED FLOWS FROM LAUREL HEIGHTS *
* PRE-PROJECT CONDITION: 100-YR, 6-HR STORM EVENT *
************************************************************************** FILE NAME: AG1HPREU.RAT
TIME/DATE OF STUDY: 16:50 11/05/2024
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.400
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 230.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS:

TC(MIN) = 12.40 RAIN INTENSITY(INCH/HOUR) = 3.52
TOTAL AREA(ACRES) = 5.60 TOTAL RUNOFF(CFS) = 6.90
**************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 270.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 337.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 704.00 CHANNEL SLOPE = 0.0327 CHANNEL BASE(FEET) = 3.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.256
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 10.32
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 7.38 AVERAGE FLOW DEPTH(FEET) = 0.35 TRAVEL TIME(MIN.) = 1.59 Tc(MIN.) = 13.99
SUBAREA AREA(ACRES) = 2.51 SUBAREA RUNOFF(CFS) = 6.87
AREA-AVERAGE RUNOFF COEFFICIENT = 0.502
TOTAL AREA(ACRES) = 8.1 PEAK FLOW RATE(CFS) = 13.25
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.39 FLOW VELOCITY(FEET/SEC.) = 8.04
LONGEST FLOWPATH FROM NODE 0.00 TO NODE 270.00 = 704.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 13.99
RAINFALL INTENSITY(INCH/HR) = 3.26
TOTAL STREAM AREA(ACRES) = 8.11
PEAK FLOW RATE(CFS) AT CONFLUENCE = 13.25
**************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS:

TC(MIN) = 16.84 RAIN INTENSITY(INCH/HOUR) = 2.89
TOTAL AREA(ACRES) = 6.30 TOTAL RUNOFF(CFS) = 10.97
**************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 16.84
RAINFALL INTENSITY(INCH/HR) = 2.89
TOTAL STREAM AREA(ACRES) = 6.30
PEAK FLOW RATE(CFS) AT CONFLUENCE = 10.97
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 13.25 13.99 3.256 8.11
2 10.97 16.84 2.889 6.30

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 22.36 13.99 3.256
2 22.73 16.84 2.889
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 22.73 Tc(MIN.) = 16.84
TOTAL AREA(ACRES) = 14.4
LONGEST FLOWPATH FROM NODE 0.00 TO NODE 270.00 = 704.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 61 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 337.00 DOWNSTREAM ELEVATION(FEET) = 336.00 STREET LENGTH(FEET) = 94.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 42.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 37.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0100 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 22.87 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.53
HALFSTREET FLOOD WIDTH(FEET) = 22.17
AVERAGE FLOW VELOCITY(FEET/SEC.) = 5.29
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 2.83
STREET FLOW TRAVEL TIME(MIN.) = 0.30 Tc(MIN.) = 17.14
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.857
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.548
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.29
TOTAL AREA(ACRES) = 14.5 PEAK FLOW RATE(CFS) = 22.76
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.53 HALFSTREET FLOOD WIDTH(FEET) = 22.17 FLOW VELOCITY(FEET/SEC.) = 5.27 DEPTH*VELOCITY(FT*FT/SEC.) = 2.82 LONGEST FLOWPATH FROM NODE 0.00 TO NODE 290.00 = 798.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.857
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5488
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.12
TOTAL AREA(ACRES) = 14.6 TOTAL RUNOFF(CFS) = 22.88
TC(MIN.) = 17.14
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 14.6 TC(MIN.) = 17.14
PEAK FLOW RATE(CFS) = 22.88
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

APPENDIX B
Modified Rational Method Output
[Post-project]
____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * (J-19964) AUBREY GLEN *
* UNDETAINED FLOWS FROM LAUREL HEIGHTS *
* POST-PROJECT CONDITION: 10-YR, 6-HR STORM EVENT *
************************************************************************** FILE NAME: AG10PSTU.RAT
TIME/DATE OF STUDY: 09:12 01/21/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 10.00
6-HOUR DURATION PRECIPITATION (INCHES) = 1.700
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 230.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS:

TC(MIN) = 7.10 RAIN INTENSITY(INCH/HOUR) = 3.57
TOTAL AREA(ACRES) = 5.60 TOTAL RUNOFF(CFS) = 14.20
**************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 266.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 94.34 FLOW LENGTH(FEET) = 566.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 15.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.28
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 14.20
PIPE TRAVEL TIME(MIN.) = 1.30 Tc(MIN.) = 8.40
LONGEST FLOWPATH FROM NODE 0.00 TO NODE 266.00 = 566.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 266.00 TO NODE 266.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 8.40
RAINFALL INTENSITY(INCH/HR) = 3.21
TOTAL STREAM AREA(ACRES) = 5.60
PEAK FLOW RATE(CFS) AT CONFLUENCE = 14.20
**************************************************************************** FLOW PROCESS FROM NODE 240.00 TO NODE 242.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 67.00
UPSTREAM ELEVATION(FEET) = 100.00
DOWNSTREAM ELEVATION(FEET) = 99.50
ELEVATION DIFFERENCE(FEET) = 0.50
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.961
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 57.39
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.479
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.17
TOTAL AREA(ACRES) = 0.05 TOTAL RUNOFF(CFS) = 0.17
**************************************************************************** FLOW PROCESS FROM NODE 242.00 TO NODE 244.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 1 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 100.00 DOWNSTREAM ELEVATION(FEET) = 99.00 STREET LENGTH(FEET) = 109.00 CURB HEIGHT(INCHES) = 8.0
STREET HALFWIDTH(FEET) = 30.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 20.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.45 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.20
HALFSTREET FLOOD WIDTH(FEET) = 2.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.08
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.41
STREET FLOW TRAVEL TIME(MIN.) = 0.87 Tc(MIN.) = 5.83
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.055
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.770
SUBAREA AREA(ACRES) = 0.18 SUBAREA RUNOFF(CFS) = 0.56
TOTAL AREA(ACRES) = 0.2 PEAK FLOW RATE(CFS) = 0.72
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.25 HALFSTREET FLOOD WIDTH(FEET) = 4.97
FLOW VELOCITY(FEET/SEC.) = 1.73 DEPTH*VELOCITY(FT*FT/SEC.) = 0.44 LONGEST FLOWPATH FROM NODE 240.00 TO NODE 244.00 = 176.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 244.00 TO NODE 252.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.50 FLOW LENGTH(FEET) = 140.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 2.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.30
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 0.72
PIPE TRAVEL TIME(MIN.) = 0.71 Tc(MIN.) = 6.54
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 252.00 = 316.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 252.00 TO NODE 252.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.766
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.11 SUBAREA RUNOFF(CFS) = 0.32
TOTAL AREA(ACRES) = 0.3 TOTAL RUNOFF(CFS) = 0.99
TC(MIN.) = 6.54
**************************************************************************** FLOW PROCESS FROM NODE 252.00 TO NODE 254.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.27 FLOW LENGTH(FEET) = 73.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 3.5 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.54
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 0.99
PIPE TRAVEL TIME(MIN.) = 0.34 Tc(MIN.) = 6.88
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 254.00 = 389.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 254.00 TO NODE 254.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.644
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 1.00 SUBAREA RUNOFF(CFS) = 2.81
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 3.76
TC(MIN.) = 6.88
**************************************************************************** FLOW PROCESS FROM NODE 254.00 TO NODE 256.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.35 FLOW LENGTH(FEET) = 65.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 6.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.24
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 3.76
PIPE TRAVEL TIME(MIN.) = 0.21 Tc(MIN.) = 7.09
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 256.00 = 454.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 256.00 TO NODE 256.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.575
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.09 SUBAREA RUNOFF(CFS) = 0.25
TOTAL AREA(ACRES) = 1.4 TOTAL RUNOFF(CFS) = 3.94
TC(MIN.) = 7.09
**************************************************************************** FLOW PROCESS FROM NODE 256.00 TO NODE 256.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.575
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.16 SUBAREA RUNOFF(CFS) = 0.44
TOTAL AREA(ACRES) = 1.6 TOTAL RUNOFF(CFS) = 4.38
TC(MIN.) = 7.09
**************************************************************************** FLOW PROCESS FROM NODE 256.00 TO NODE 258.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.57 FLOW LENGTH(FEET) = 43.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 7.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.46
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 4.38
PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 7.22
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 258.00 = 497.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 258.00 TO NODE 258.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.533
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.33
TOTAL AREA(ACRES) = 1.7 TOTAL RUNOFF(CFS) = 4.65
TC(MIN.) = 7.22
**************************************************************************** FLOW PROCESS FROM NODE 258.00 TO NODE 260.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.32 FLOW LENGTH(FEET) = 68.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 7.5 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.56
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 4.65
PIPE TRAVEL TIME(MIN.) = 0.20 Tc(MIN.) = 7.43
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 260.00 = 565.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 260.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.470
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.07 SUBAREA RUNOFF(CFS) = 0.19
TOTAL AREA(ACRES) = 1.9 TOTAL RUNOFF(CFS) = 4.94
TC(MIN.) = 7.43
**************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 262.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.62 FLOW LENGTH(FEET) = 38.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 7.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.66
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 4.94
PIPE TRAVEL TIME(MIN.) = 0.11 Tc(MIN.) = 7.54
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 262.00 = 603.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 262.00 TO NODE 262.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.437
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.24 SUBAREA RUNOFF(CFS) = 0.64
TOTAL AREA(ACRES) = 2.1 TOTAL RUNOFF(CFS) = 5.53
TC(MIN.) = 7.54
**************************************************************************** FLOW PROCESS FROM NODE 262.00 TO NODE 264.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.47 FLOW LENGTH(FEET) = 53.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 8.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.84
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 5.53
PIPE TRAVEL TIME(MIN.) = 0.15 Tc(MIN.) = 7.69
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 264.00 = 656.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 264.00 TO NODE 264.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.393
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.25 SUBAREA RUNOFF(CFS) = 0.65
TOTAL AREA(ACRES) = 2.3 TOTAL RUNOFF(CFS) = 6.11
TC(MIN.) = 7.69
**************************************************************************** FLOW PROCESS FROM NODE 264.00 TO NODE 266.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 8.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.00
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 6.11
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.72
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 266.00 = 668.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 266.00 TO NODE 266.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 7.72
RAINFALL INTENSITY(INCH/HR) = 3.38
TOTAL STREAM AREA(ACRES) = 2.34
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.11
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 14.20 8.40 3.206 5.60
2 6.11 7.72 3.384 2.34

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 19.18 7.72 3.384
2 19.99 8.40 3.206
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 19.99 Tc(MIN.) = 8.40
TOTAL AREA(ACRES) = 7.9
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 266.00 = 668.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 266.00 TO NODE 270.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.68 FLOW LENGTH(FEET) = 32.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 17.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.95
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.99
PIPE TRAVEL TIME(MIN.) = 0.07 Tc(MIN.) = 8.46
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 270.00 = 700.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.190
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7284
SUBAREA AREA(ACRES) = 0.17 SUBAREA RUNOFF(CFS) = 0.42
TOTAL AREA(ACRES) = 8.1 TOTAL RUNOFF(CFS) = 19.99
TC(MIN.) = 8.46
NOTE: PEAK FLOW RATE DEFAULTED TO UPSTREAM VALUE
**************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.76 FLOW LENGTH(FEET) = 248.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.36
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 19.99
PIPE TRAVEL TIME(MIN.) = 0.65 Tc(MIN.) = 9.11
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 290.00 = 948.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 9.11
RAINFALL INTENSITY(INCH/HR) = 3.04
TOTAL STREAM AREA(ACRES) = 8.11
PEAK FLOW RATE(CFS) AT CONFLUENCE = 19.99
**************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS:

TC(MIN) = 16.84 RAIN INTENSITY(INCH/HOUR) = 2.05
TOTAL AREA(ACRES) = 6.30 TOTAL RUNOFF(CFS) = 7.80
**************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 1 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 100.00 DOWNSTREAM ELEVATION(FEET) = 99.00 STREET LENGTH(FEET) = 100.00 CURB HEIGHT(INCHES) = 8.0
STREET HALFWIDTH(FEET) = 30.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 20.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 7.90 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.46
HALFSTREET FLOOD WIDTH(FEET) = 16.84
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.90
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 1.34
STREET FLOW TRAVEL TIME(MIN.) = 0.57 Tc(MIN.) = 17.41
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.003
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .8400
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.609
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.20
TOTAL AREA(ACRES) = 6.4 PEAK FLOW RATE(CFS) = 7.83
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.46 HALFSTREET FLOOD WIDTH(FEET) = 16.84 FLOW VELOCITY(FEET/SEC.) = 2.88 DEPTH*VELOCITY(FT*FT/SEC.) = 1.33 LONGEST FLOWPATH FROM NODE 240.00 TO NODE 290.00 = 768.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.003
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .6900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6101
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.08
TOTAL AREA(ACRES) = 6.5 TOTAL RUNOFF(CFS) = 7.92
TC(MIN.) = 17.41
**************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 17.41
RAINFALL INTENSITY(INCH/HR) = 2.00
TOTAL STREAM AREA(ACRES) = 6.48
PEAK FLOW RATE(CFS) AT CONFLUENCE = 7.92
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 19.99 9.11 3.041 8.11
2 7.92 17.41 2.003 6.48

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 24.14 9.11 3.041
2 21.08 17.41 2.003
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 24.14 Tc(MIN.) = 9.11
TOTAL AREA(ACRES) = 14.6
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 290.00 = 948.00 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 14.6 TC(MIN.) = 9.11
PEAK FLOW RATE(CFS) = 24.14
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * (J-19964) AUBREY GLEN *
* UNDETAINED FLOWS FROM LAUREL HEIGHTS *
* POST-PROJECT CONDITION: 50-YR, 6-HR STORM EVENT *
************************************************************************** FILE NAME: AG50PSTU.RAT
TIME/DATE OF STUDY: 09:20 01/21/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 50.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.300
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 230.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS:

TC(MIN) = 7.10 RAIN INTENSITY(INCH/HOUR) = 4.83
TOTAL AREA(ACRES) = 5.60 TOTAL RUNOFF(CFS) = 19.20
**************************************************************************** FLOW PROCESS FROM NODE 230.00 TO NODE 266.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 94.34 FLOW LENGTH(FEET) = 566.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 17.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.91
ESTIMATED PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 19.20
PIPE TRAVEL TIME(MIN.) = 1.19 Tc(MIN.) = 8.29
LONGEST FLOWPATH FROM NODE 0.00 TO NODE 266.00 = 566.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 266.00 TO NODE 266.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 8.29
RAINFALL INTENSITY(INCH/HR) = 4.37
TOTAL STREAM AREA(ACRES) = 5.60
PEAK FLOW RATE(CFS) AT CONFLUENCE = 19.20
**************************************************************************** FLOW PROCESS FROM NODE 240.00 TO NODE 242.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 67.00
UPSTREAM ELEVATION(FEET) = 100.00
DOWNSTREAM ELEVATION(FEET) = 99.50
ELEVATION DIFFERENCE(FEET) = 0.50
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.961
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 57.39
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.060
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.23
TOTAL AREA(ACRES) = 0.05 TOTAL RUNOFF(CFS) = 0.23
**************************************************************************** FLOW PROCESS FROM NODE 242.00 TO NODE 244.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 1 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 100.00 DOWNSTREAM ELEVATION(FEET) = 99.00 STREET LENGTH(FEET) = 109.00 CURB HEIGHT(INCHES) = 8.0
STREET HALFWIDTH(FEET) = 30.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 20.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.61 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.24
HALFSTREET FLOOD WIDTH(FEET) = 4.16
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.74
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.41
STREET FLOW TRAVEL TIME(MIN.) = 1.04 Tc(MIN.) = 6.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.385
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.770
SUBAREA AREA(ACRES) = 0.18 SUBAREA RUNOFF(CFS) = 0.75
TOTAL AREA(ACRES) = 0.2 PEAK FLOW RATE(CFS) = 0.95
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.27 HALFSTREET FLOOD WIDTH(FEET) = 6.16
FLOW VELOCITY(FEET/SEC.) = 1.79 DEPTH*VELOCITY(FT*FT/SEC.) = 0.49 LONGEST FLOWPATH FROM NODE 240.00 TO NODE 244.00 = 176.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 244.00 TO NODE 252.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.50 FLOW LENGTH(FEET) = 140.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 3.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.59
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 0.95
PIPE TRAVEL TIME(MIN.) = 0.65 Tc(MIN.) = 6.65
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 252.00 = 316.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 252.00 TO NODE 252.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.040
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.11 SUBAREA RUNOFF(CFS) = 0.43
TOTAL AREA(ACRES) = 0.3 TOTAL RUNOFF(CFS) = 1.32
TC(MIN.) = 6.65
**************************************************************************** FLOW PROCESS FROM NODE 252.00 TO NODE 254.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.27 FLOW LENGTH(FEET) = 73.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 4.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.86
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 1.32
PIPE TRAVEL TIME(MIN.) = 0.32 Tc(MIN.) = 6.97
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 254.00 = 389.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 254.00 TO NODE 254.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.892
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 1.00 SUBAREA RUNOFF(CFS) = 3.77
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 5.05
TC(MIN.) = 6.97
**************************************************************************** FLOW PROCESS FROM NODE 254.00 TO NODE 256.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.35 FLOW LENGTH(FEET) = 65.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 7.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.69
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 5.05
PIPE TRAVEL TIME(MIN.) = 0.19 Tc(MIN.) = 7.16
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 256.00 = 454.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 256.00 TO NODE 256.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.807
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.09 SUBAREA RUNOFF(CFS) = 0.33
TOTAL AREA(ACRES) = 1.4 TOTAL RUNOFF(CFS) = 5.29
TC(MIN.) = 7.16
**************************************************************************** FLOW PROCESS FROM NODE 256.00 TO NODE 256.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.807
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.16 SUBAREA RUNOFF(CFS) = 0.59
TOTAL AREA(ACRES) = 1.6 TOTAL RUNOFF(CFS) = 5.89
TC(MIN.) = 7.16
**************************************************************************** FLOW PROCESS FROM NODE 256.00 TO NODE 258.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.57 FLOW LENGTH(FEET) = 43.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 8.5 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.94
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 5.89
PIPE TRAVEL TIME(MIN.) = 0.12 Tc(MIN.) = 7.28
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 258.00 = 497.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 258.00 TO NODE 258.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.756
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.44
TOTAL AREA(ACRES) = 1.7 TOTAL RUNOFF(CFS) = 6.26
TC(MIN.) = 7.28
**************************************************************************** FLOW PROCESS FROM NODE 258.00 TO NODE 260.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.32 FLOW LENGTH(FEET) = 68.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 8.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.04
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 6.26
PIPE TRAVEL TIME(MIN.) = 0.19 Tc(MIN.) = 7.47
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 260.00 = 565.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 260.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.679
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.07 SUBAREA RUNOFF(CFS) = 0.25
TOTAL AREA(ACRES) = 1.9 TOTAL RUNOFF(CFS) = 6.66
TC(MIN.) = 7.47
**************************************************************************** FLOW PROCESS FROM NODE 260.00 TO NODE 262.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.62 FLOW LENGTH(FEET) = 38.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 9.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.15
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 6.66
PIPE TRAVEL TIME(MIN.) = 0.10 Tc(MIN.) = 7.57
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 262.00 = 603.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 262.00 TO NODE 262.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.637
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.24 SUBAREA RUNOFF(CFS) = 0.86
TOTAL AREA(ACRES) = 2.1 TOTAL RUNOFF(CFS) = 7.46
TC(MIN.) = 7.57
**************************************************************************** FLOW PROCESS FROM NODE 262.00 TO NODE 264.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.47 FLOW LENGTH(FEET) = 53.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 9.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.34
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 7.46
PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 7.71
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 264.00 = 656.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 264.00 TO NODE 264.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.583
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7700
SUBAREA AREA(ACRES) = 0.25 SUBAREA RUNOFF(CFS) = 0.88
TOTAL AREA(ACRES) = 2.3 TOTAL RUNOFF(CFS) = 8.26
TC(MIN.) = 7.71
**************************************************************************** FLOW PROCESS FROM NODE 264.00 TO NODE 266.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 10.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.51
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 8.26
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.74
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 266.00 = 668.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 266.00 TO NODE 266.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 7.74
RAINFALL INTENSITY(INCH/HR) = 4.57
TOTAL STREAM AREA(ACRES) = 2.34
PEAK FLOW RATE(CFS) AT CONFLUENCE = 8.26
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 19.20 8.29 4.373 5.60
2 8.26 7.74 4.571 2.34

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 26.18 7.74 4.571
2 27.10 8.29 4.373
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 27.10 Tc(MIN.) = 8.29
TOTAL AREA(ACRES) = 7.9
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 266.00 = 668.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 266.00 TO NODE 270.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.68 FLOW LENGTH(FEET) = 32.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 8.63
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 27.10
PIPE TRAVEL TIME(MIN.) = 0.06 Tc(MIN.) = 8.35
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 270.00 = 700.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 270.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.352
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7700
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.7281
SUBAREA AREA(ACRES) = 0.17 SUBAREA RUNOFF(CFS) = 0.57
TOTAL AREA(ACRES) = 8.1 TOTAL RUNOFF(CFS) = 27.10
TC(MIN.) = 8.35
NOTE: PEAK FLOW RATE DEFAULTED TO UPSTREAM VALUE
**************************************************************************** FLOW PROCESS FROM NODE 270.00 TO NODE 290.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.76 FLOW LENGTH(FEET) = 248.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 8.63
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPE-FLOW(CFS) = 27.10
PIPE TRAVEL TIME(MIN.) = 0.48 Tc(MIN.) = 8.83
LONGEST FLOWPATH FROM NODE 240.00 TO NODE 290.00 = 948.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 290.00 TO NODE 290.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

Santee City CouncilMay 28, 2025

Santee City Council
May 28, 2025