Anaheim City Council
December 9, 2025

bigger and heavier), Caltrans also recommends that bicycle storage facilities be designed to accommodate a range of bicycle styles, sizes, and weights.

2. Continue to incorporate Complete Streets in project development, including connections to existing and proposed active transportation facilities in the project vicinity. Caltrans supports the design of Complete Streets that include high-quality pedestrian, bicycle, and transit facilities that are safe and comfortable for users of all ages and abilities. Improvements may include providing secure bicycle parking, pedestrian-oriented LED lighting, wayfinding signage, and comfortable connections to nearby active transportation and/or transit facilities. Complete Streets improvements also promote regional connectivity, improve air quality, reduce congestion, promote improved first- /last-mile connections, and increase safety for all modes of transportation.

Equity

3. The Department firmly embraces racial equity, inclusion, and diversity. These values are foundational to achieving our vision of a cleaner, safer, and more accessible and more connected transportation system.

4. Considering the need for equitable access to amenities and resources, please consider referencing the City's own General plan Environmental Justice (EJ) Element that is in development. The Element discusses EJ goals and policies for accessibility to public facilities, safety, recreation, and green space. Ensure that residents and visitors from all socioeconomic backgrounds can access the new facilities in development of the OC River Walk.

Encroachment Permit

5. Any work performed within Caltrans right-of-way (R/W) will require discretionary review and approval by Caltrans and an encroachment permit will be required for any work within the Caltrans R/W prior to construction. Prior to submitting to Caltrans Permit's branch, applicant should fill out Applicant's Checklist to Determine Applicable Review Process (QMAP List) Form TR-0416 to determine if project oversight/coordination with Caltrans Project Manager is needed.

Applicant must submit a signed Standard Encroachment Permit application form TR-0100 along with a deposit payable to Caltrans. Deposit amount will be dependent on when the application is submitted. Public corporations are legally exempt from encroachment permit fees. Please note that all utility work should "Provide a safe and reliable transportation network that serves all people and respects the environment" Ms. Ana Straabe
April 20, 2023

be disclosed prior to permit submittal, and utility companies are to apply for separate permits for their corresponding work.

6. Project plans and traffic control plans must be stamped and signed by a licensed engineer. For all plans, including traffic control plans, Caltrans R/W lines should be clearly labeled, which includes existing and proposed (if there are any changes to Caltrans R/W), the north arrow, the edge of pavement, and edge of the sidewalk, if applicable. When submitting the application, please include final Environmental Clearance Documentation, relevant design details including design exception approvals and construction and drainage plans, traffic control plans, traffic management plan and traffic impact study if proposed traffic delay of 30 minutes above normal recurring traffic delay is anticipated, any Caltrans R/W certifications if needed, maintenance agreement as needed, shoring plans for any excavation 5-feet or more, ADA certification, and any letter of authorizations.

7. Please submit all applications and associated documents/plans via email to [email protected] further notice. Caltrans Encroachment Permits will be transitioning to an online web portal base for all applications in Fall 2023.

Further details to be announced on the Caltrans Encroachment Permits homepage. Additional information regarding encroachment permits may be obtained by contacting the Caltrans Permits Office at ( 657) 328-6246. For specific details on Caltrans Encroachment Permits procedure and any future updates regarding the application process and permit rates, please visit the Caltrans Encroachment Permits homepage at
https://dot.ca.gov /programs/traffic-operations/ep.

Please continue to coordinate with Caltrans for any future developments that could potentially impact State transportation facilities. If you have any questions, please do not hesitate to contact Maryam Molavi, at [email protected].

Sincerely,
~
Scott Shelley
Branch Chief, Regional-LOR-Transit Planning
District 12
"Provide a safe and reliable transportation network that serves all people and respects the environment" From: Ana Straabe
To: William Halligan
Cc: Jose Jimenez; Jacob Peterson; Mark Krebs
Subject: FW: [EXTERNAL] DEIR for OC River Walk Project
Date: Monday, April 24, 2023 10:47:20 AM
Aloha & FYI
Ana Straabe
Principal Project Planner
Community Services Department │ Parks Division
200 South Anaheim Boulevard │ Suite 433
Anaheim, CA 92805
Office (714) 765-4463
PARKS DIVISION MISSION STATEMENT: To enrich the quality of life of individuals, families, and the community by providing excellent parks, trails, and recreational facilities through outstanding customer service, sustainable environmental practices, and strong employee development and commitment.

From: Chris Schaefer <[email protected]> Sent: Monday, April 24, 2023 10:04 AM
To: Ana Straabe <[email protected]>
Subject: [EXTERNAL] DEIR for OC River Walk Project
Warning: This email originated from outside the City of Anaheim. Do not click links or open attachments unless you recognize the sender and are expecting the message.

Hi Ana,
Staff has reviewed the proposed DEIR for the OC River Walk Project and has no comment. Best wishes on the project.

Chris
Chris Schaefer, AICP
Planning Manager
City of Fullerton
303 W. Commonwealth Avenue, Fullerton, CA 92832
714-738-6884
[email protected]
Disclaimer: This electronic transmission, and any documents attached hereto, may contain confidential and/or legally privileged information. The information is intended only for use by the recipient named above. If you have received this electronic message in error, please notify the sender and delete the electronic message. Any disclosure, copying, distribution, or use of the contents of information received in error is strictly prohibited.

cityofirvine.org
City of Irvine, 1 Civic Center Plaza, P.O. Box 19575, Irvine, California 92623-9575 949-724-6000 April 24, 2023
Ana Straabe, Principal Project Planner
City of Anaheim
Community Services Department, Parks Division
200 S. Anaheim Boulevard, Suite 433
Anaheim, CA 92805
Subject: Notice of Preparation of a Draft Environmental Impact Report and Scoping Meeting for the OC River Walk Project
Dear Ana Straabe:

Staff is in receipt of the Notice of Preparation of a Draft Environmental Impact Report and Scoping Meeting for the OC River Walk Project within the City of Anaheim. The project proposes various multi-purpose improvement opportunities as part of an effort to transform the Santa Ana River corridor and portions of the existing Santa Ana River Trail (SART) into a primary connective open space.

Staff has no comments. If you have any questions, please contact me at [email protected] or 949-724-6361.

Sincerely,
Tiffany Lin
Associate Planner
ec: Marika Poynter, Manager of Planning Services

From: Chad Ortlieb
To: William Halligan; [email protected]
Subject: RE: OC River Walk NOP
Date: Tuesday, April 4, 2023 1:54:41 PM
Attachments: image002.png
image003.png
Hi Bill and Ana,
The City of Orange has no comments or questions for the OC River Walk NOP at this time.

Thank you,
Chad Ortlieb
Principal Planner
City of Orange
(714) 744-7237
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CHAIRPERSON
Laura Miranda
Luisefio

VICE CHAIRPERSON
Reginald Pagaling
Chumash

SECRETARY
Sara Dutschke
Miwok

COMMISSIONER
Isaac Bojorquez
Ohlone-Costanoan

COMMISSIONER
Buffy McQuillen
Yokayo Pomo, Yuki,
Nomlaki

COMMISSIONER
Wayne Nelson
Luisefio

COMMISSIONER
Stanley Rodriguez
Kumeyaay

COMMISSIONER
[Vacant)

COMMISSIONER
[Vacant]

EXECUTIVE SEC RETARY
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NAHC HEADQUARTERS
1550 Harbor Boulevard
Suite 100
West Sacramento,
California 9569 1
(916) 373-3710
[email protected]
NAHC.ca.gov
STATE OF CALIFORNIA Gavin Newsom Governor

NATIVE AMERICAN HERITAGE COMMISSION
March 20, 2023
Ana Straabe
City of Anaheim
200 South Anaheim Boulevard
City of Anaheim, CA 92805
Re: 2023030639, OC River Walk Project, Orange County
Dear Ms. Straabe:

The Native American Heritage Commission (NAHC) has received the Notice of Preparation (NOP), Draft Environmental Impact Report {DEIR) or Early Consultation for the project referenced above. The California Environmental Quality Act {CEQA) {Pub. Resources Code §21000 et seq.) , specifically Public Resources Code §21084. l, states that a project that may cause a substantial adverse change in the significance of a historical resource, is a project that may have a significant effect on the environment. (Pub. Resources Code§ 21084.1; Cal. Code Regs., tit.14, § 15064.5 {b) (CEQA Guidelines § 15064.5 {b)). If there is substantial evidence, in light of the whole record before a lead agency, that a project may have a significant effect on the environment, an Environmental Impact Report {EIR) shall be prepared. (Pub. Resources Code §21080 (d); Cal. Code Regs., tit. 14, § 5064 subd.(a){l) {CEQA Guidelines§ 15064 {a){l)) .

In order to determine whether a project will cause a substantial adverse change in the significance of a historical resource, a lead agency will need to determine whether there are historical resources within the area of potential effect {APE).

CEQA was amended significantly in 2014. Assembly Bill 52 (Gatto, Chapter 532, Statutes of 2014) (AB 52) amended CEQA to create a separate category of cultural resources, "tribal cultural resources" {Pub. Resources Code §21074) and provides that a project with an effect that may cause a substantial adverse change in the significance of a tribal cultural resource is a project that may have a significant effect on the environment. {Pub. Resources Code §21084.2). Public agencies shall, when feasible, avoid damaging effects to any tribal cultural resource. {Pub. Resources Code §21084.3 {a)). AB 52 applies to any project for which a notice of preparation, a notice of negative declaration, or a mitigated negative declaration is filed on or after July 1, 2015. If your project involves the adoption of or amendment to a general plan or a specific plan, or the designation or proposed designation of open space, on or after March 1, 2005, it may also be subject to Senate Bill 18 {Burton, Chapter 905, Statutes of 2004) (SB 18).

Both SB 18 and AB 52 have tribal consultation requirements. If your project is also subject to the federal National Environmental Policy Act (42 U.S.C. § 4321 et seq.) {NEPA), the tribal consultation requirements of Section l 06 of the National Historic Preservation Act of 1966 { 154 U.S.C. 300101 , 36 C.F.R. §800 et seq.) may also apply.

The NAHC recommends consultation with California Native American tribes that are traditionally and culturally affiliated with the geographic area of your proposed project as early as possible in order to avoid inadvertent discoveries of Native American human remains and best protect tribal cultural resources. Below is a brief summary of portions of AB 52 and SB 18 as well as the NAHC's recommendations for conducting cultural resources assessments.

Consult your legal counsel about compliance with AB 52 and SB 18 as well as compliance with any other applicable laws.

AB 52

AB 52 has added to CEQA the additional requirements listed below, along with many other requirements:

1. Fourteen Day Period to Provide Notice of Completion of an Application/Decision to Undertake a Project:

Within fourteen ( 14) days of determining that an application for a project is complete or of a decision by a public agency to undertake a project, a lead agency shall provide formal notification to a designated contact of, or tribal representative of, traditionally and culturally affiliated California Native American tribes that have requested notice, to be accomplished by at least one written notice that includes:
a. A brief description of the project.
b. The lead agency contact information.
c. Notification that the California Native American tribe has 30 days to request consultation. (Pub.

Resources Code §21080.3.1 (d)).
d. A "California Native American tribe" is defined as a Native American tribe located in California that is on the contact list maintained by the NAHC for the purposes of Chapter 905 of Statutes of 2004 (SB 18). (Pub. Resources Code §21073).

2. Begin Consultation Within 30 Days of Receiving a Tribe's Request for Consultation and Before Releasing a Negative Declaration, Mitigated Negative Declaration, or Environmental Impact Report: A lead agency shall begin the consultation process within 30 days of receiving a request for consultation from a California Native American tribe that is traditionally and culturally affiliated with the geographic area of the proposed project. (Pub. Resources Code §21080.3.1, subds. ( d) and ( e)) and prior to the release of a negative declaration, mitigated negative declaration or Environmental Impact Report. (Pub. Resources Code §21080.3.1 (b)). a. For purposes of AB 52, "consultation shall have the same meaning as provided in Gov. Code §65352.4 (SB 18). (Pub. Resources Code §21080.3.1 (b)).

3. Mandatory Topics of Consultation If Requested by a Tribe: The following topics of consultation, if a tribe requests to discuss them, are mandatory topics of consultation:
a. Alternatives to the project.
b. Recommended mitigation measures.
c. Significant effects. (Pub. Resources Code §21080.3.2 (a)) .

4. Discretionary Topics of Consultation: The following topics are discretionary topics of consultation:
a. Type of environmental review necessary.
b. Significance of the tribal cultural resources.
c. Significance of the project's impacts on tribal cultural resources. d. If necessary, project alternatives or appropriate measures for preservation or mitigation that the tribe may recommend to the lead agency. (Pub. Resources Code §21080.3.2 (a)) .

5. Confidentiality of Information Submitted by a Tribe During the Environmental Review Process: With some exceptions, any information, including but not limited to, the location, description, and use of tribal cultural resources submitted by a California Native American tribe during the environmental review process shall not be included in the environmental document or otherwise disclosed by the lead agency or any other public agency to the public, consistent with Government Code §6254 (r) and §6254.10. Any information submitted by a California Native American tribe during the consultation or environmental review process shall be published in a confidential appendix to the environmental document unless the tribe that provided the information consents, in writing, to the disclosure of some or all of the information to the public. (Pub. Resources Code §21082.3 (c) ( 1)).

6. Discussion of Impacts to Tribal Cultural Resources in the Environmental Document: If a project may have a significant impact on a tribal cultural resource, the lead agency's environmental document shall discuss both of the following :
a. Whether the proposed project has a significant impact on an identified tribal cultural resource. b. Whether feasible alternatives or mitigation measures, including those measures that may be agreed to pursuant to Public Resources Code §21082.3, subdivision (a), avoid or substantially lessen the impact on the identified tribal cultural resource. (Pub. Resources Code §21082.3 (b)) .

7. Conclusion of Consultation: Consultation with a tribe shall be considered concluded when either of the following occurs:
a. The parties agree to measures to mitigate or avoid a significant effect, if a significant effect exists, on a tribal cultural resource; or
b. A party, acting in good faith and after reasonable effort, concludes that mutual agreement cannot be reached. (Pub. Resources Code §21080.3.2 (b)) .

8. Recommending Mitigation Measures Agreed Upon in Consultation in the Environmental Document: Any mitigation measures agreed upon in the consultation conducted pursuant to Public Resources Code §21080.3.2 shall be recommended for inclusion in the environmental document and in an adopted mitigation monitoring and reporting program, if determined to avoid or lessen the impact pursuant to Public Resources Code §21082.3, subdivision (b) , paragraph 2, and shall be fully enforceable. (Pub. Resources Code §21082.3 (a)).

9. Required Consideration of Feasible Mitigation: If mitigation measures recommended by the staff of the lead agency as a result of the consultation process are not included in the environmental document or if there are no agreed upon mitigation measures at the conclusion of consultation, or if consultation does not occur, and if substantial evidence demonstrates that a project will cause a significant effect to a tribal cultural resource, the lead agency shall consider feasible mitigation pursuant to Public Resources Code §21084.3 (b) . (Pub. Resources Code §21082.3 (e)).

10. Examples of Mitigation Measures That, If Feasible, May Be Considered to Avoid or Minimize Significant Adverse Impacts to Tribal Cultural Resources:
a. Avoidance and preservation of the resources in place, including, but not limited to:
i. Planning and construction to avoid the resources and protect the cultural and natural context.
ii. Planning greenspace, parks, or other open space, to incorporate the resources with culturally appropriate protection and management criteria.
b. Treating the resource with culturally appropriate dignity, taking into account the tribal cultural values and meaning of the resource, including, but not limited to, the following:
i. Protecting the cultural character and integrity of the resource. ii. Protecting the traditional use of the resource.
iii. Protecting the confidentiality of the resource.
c. Permanent conservation easements or other interests in real property, with culturally appropriate management criteria for the purposes of preserving or utilizing the resources or places. d. Protecting the resource. (Pub. Resource Code §21084.3 (b)) . e. Please note that a federally recognized California Native American tribe or a non-federally recognized California Native American tribe that is on the contact list maintained by the NAHC to protect a California prehistoric, archaeological, cultural, spiritual, or ceremonial place may acquire and hold conservation easements if the conservation easement is voluntarily conveyed. (Civ. Code §815.3 (cl). f. Please note that it is the policy of the state that Native American remains and associated grave artifacts shall be repatriated . (Pub. Resources Code §5097.991 ).

11. Prerequisites for Certifying an Environmental Impact Report or Adopting a Mitigated Negative Declaration or Negative Declaration with a Significant Impact on an Identified Tribal Cultural Resource: An Environmental Impact Report may not be certified, nor may a mitigated negative declaration or a negative declaration be adopted unless one of the following occurs:
a. The consultation process between the tribes and the lead agency has occurred as provided in Public Resources Code §21080.3. l and §21080.3.2 and concluded pursuant to Public Resources Code § 21080.3.2.
b. The tribe that requested consultation failed to provide comments to the lead agency or otherwise failed to engage in the consultation process.
c. The lead agency provided notice of the project to the tribe in compliance with Public Resources Code §21080.3. l (d) and the tribe failed to request consultation within 30 days. (Pub. Resources Code §21082.3 (d)) .

The NAHC's PowerPoint presentation titled, "Tribal Consultation Under AB 52: Requirements and Best Practices" may be found online at: http://nahc.ca.gov/wp-content/uploads/2015/ l 0/AB52TribaIConsultation Cal EPA PDF.pdf

SB 18 applies to local governments and requires local governments to contact, provide notice to, refer plans to, and consult with tribes prior to the adoption or amendment of a general plan or a specific plan, or the designation of open space. (Gov. Code §65352.3). Local governments should consult the Governor's Office of Planning and Research 's "Tribal Consultation Guidelines," which can be found online at:
https://www.opr.ca.gov/docs/09 14 05 Updated Guidelines 922.pdf.

Some of SB l 8's provisions include:

1. Tribal Consultation: If a local government considers a proposal to adopt or amend a general plan or a specific plan, or to designate open space it is required to contact the appropriate tribes identified by the NAHC by requesting a "Tribal Consultation List." If a tribe, once contacted, requests consultation the local government must consult with the tribe on the plan proposal. A tribe hos 90 days from the dote of receipt of notification to request consultation unless a shorter timefrome hos been agreed to by the tribe. (Gov. Code §65352.3 (a)(2)).

2. No Statutory Time Limit on SB 18 Tribal Consultation. There is no statutory time limit on SB 18 tribal consultation.

3. Confidentiality: Consistent with the guidelines developed and adopted by the Office of Planning and Research pursuant to Gov. Code §65040.2, the city or county shall protect the confidentiality of the information concerning the specific identity, location, character, and use of places, features and objects described in Public Resources Code §5097.9 and §5097.993 that are within the city 's or county's jurisdiction. (Gov. Code §65352.3 (b)) .

4. Conclusion of SB 18 Tribal Consultation: Consultation should be concluded at the point in which:
a. The parties to the consultation come to a mutual agreement concerning the appropriate measures for preservation or mitigation; or
b. Either the local government or the tribe, acting in good faith and after reasonable effort, concludes that mutual agreement cannot be reached concerning the appropriate measures of preservation or mitigation. (Tribal Consultation Guidelines, Governor's Office of Planning and Research (2005) at p . 18).

Agencies should be aware that neither AB 52 nor SB 18 precludes agencies from initiating tribal consultation with tribes that are traditionally and culturally affiliated with their jurisdictions before the timeframes provided in AB 52 and SB 18. For that reason, we urge you to continue to request Native American Tribal Contact Lists and "Sacred Lands File" searches from the NAHC. The request forms can be found online at: http://nahc.ca.gov/resources/forms/.

NAHC Recommendations for Cultural Resources Assessments To adequately assess the existence and significance of tribal cultural resources and plan for avoidance, preservation in place, or barring both, mitigation of project-related impacts to tribal cultural resources, the NAHC recommends the following actions:

1. Contact the appropriate regional California Historical Research Information System (CHRIS) Center (https://ohp.parks.ca.gov /?page_id=30331) for an archaeological records search. The records search will determine:
a. If part or all of the APE has been previously surveyed for cultural resources. b. If any known cultural resources have already been recorded on or adjacent to the APE. c. If the probability is low, moderate, or high that cultural resources are located in the APE. d. If a survey is required to determine whether previously unrecorded cultural resources are present.

2. If an archaeological inventory survey is required, the final stage is the preparation of a professional report detailing the findings and recommendations of the records search and field survey. a. The final report containing site forms, site significance, and mitigation measures should be submitted immediately to the planning department. All information regarding site locations, Native American human remains, and associated funerary objects should be in a separate confidential addendum and not be made available for public disclosure.
b. The final written report should be submitted within 3 months after work has been completed to the appropriate regional CHRIS center.

3. Contact the NA HC for:
a. A Sacred Lands File search. Remember that tribes do not always record their sacred sites in the Sacred Lands File, nor are they required to do so. A Sacred Lands File search is not a substitute for consultation with tribes that are traditionally and culturally affiliated with the geographic area of the project's APE.
b. A Native American Tribal Consultation List of appropriate tribes for consultation concerning the project site and to assist in planning for avoidance, preservation in place, or, failing both, mitigation measures.

4. Remember that the lack of surface evidence of archaeological resources (including tribal cultural resources) does not preclude their subsurface existence.
a. Lead agencies should include in their mitigation and monitoring reporting program plan provisions for the identification and evaluation of inadvertently discovered archaeological resources per Cal. Code Regs., tit. 14, § l 5064.5(f) (CEQA Guidelines§ l 5064.5(f)). In areas of identified archaeological sensitivity, a certified archaeologist and a culturally affiliated Native American with knowledge of cultural resources should monitor all ground-disturbing activities.
b. Lead agencies should include in their mitigation and monitoring reporting program plans provisions for the disposition of recovered cultural items that are not burial associated in consultation with culturally affiliated Native Americans.
c. Lead agencies should include in their mitigation and monitoring reporting program plans provisions for the treatment and disposition of inadvertently discovered Native American human remains. Health and Safety Code §7050.5, Public Resources Code §5097.98, and Cal. Code Regs., tit. 14, § 15064.5, subdivisions (d) and (e) (CEQA Guidelines§ 15064.5, subds. (d) and (e)) address the processes to be followed in the event of an inadvertent discovery of any Native American human remains and associated grave goods in a location other than a dedicated cemetery.

If you have any questions or need additional information, please contact me at my email address:

[email protected].

Sincerely,
Andrew Green
Cultural Resources Analyst
cc: State Clearinghouse

From: Ana Straabe
To: William Halligan
Cc: Jacob Peterson; Mark Krebs
Subject: FW: [EXTERNAL] CEQA NOP for OC River Walk Project Date: Monday, April 17, 2023 2:16:41 PM
Attachments: ocwdlogo_bc01930d-069a-4b8c-ab6b-cd69b8dbb231.png template05_sm_twitter_1ec5fca1-3c01-4a7c-9061-1608511af66e11111.png FYI
Ana Straabe
Principal Project Planner
Community Services Department │ Parks Division
200 South Anaheim Boulevard │ Suite 433
Anaheim, CA 92805
Office (714) 765-4463
PARKS DIVISION MISSION STATEMENT: To enrich the quality of life of individuals, families, and the community by providing excellent parks, trails, and recreational facilities through outstanding customer service, sustainable environmental practices, and strong employee development and commitment.

From: Dadakis, Jason <[email protected]>
Sent: Monday, April 17, 2023 10:51 AM
To: Jose Jimenez <[email protected]>
Cc: [email protected]; Ana Straabe <[email protected]>; O'Toole, Kevin <[email protected]>; Nevill, Shawn <[email protected]>; Kennedy, John <[email protected]>; Olsen, Chris <[email protected]>
Subject: [EXTERNAL] CEQA NOP for OC River Walk Project
Warning: This email originated from outside the City of Anaheim. Do not click links or open attachments unless you recognize the sender and are expecting the message.

Hi JJ,
We met previously last October at a kickoff meeting for the OC River Walk Project held at ARTIC with staff from Anaheim, your consultants, and OCWD.

OCWD staff noticed that the CEQA NOP for the project was posted late last month and that comments are due next Monday, April 24. We’ve noticed that the NOP didn’t include a few items of interest to OCWD.

1. Conveyance Facilities. There appears to be no discussion of conveyance facilities. NOP indicates “[t]he river impoundments would be designed to be filled with and infiltrate water from the adjacent GWRS pipeline (from the proposed Burris basin turnout structure)” (Section

1.4.1.2 on page 9). Our turnout to Burris would not convey flows directly to the SAR and we have not done any CEQA to cover any facilities that would put water from Burris into the River. Currently, outflows can only occur through the culvert to Ball Road Basin.

2. GWRS Water in SAR. The CEQA for our Burris turnout project included a component that allowed some occasional, intermittent low volume maintenance activity-related flows of GWRS water into the SAR indirectly through upstream releases into the Carbon Diversion Channel (i.e., not from the Burris turnout itself, see #1) . To date, we have only studied the subsurface retention/travel time from the infiltration of recycled water in the SAR channel associated with the River Walk project. We have not otherwise studied the impacts, water quality or otherwise, of discharging GWRS water to the SAR in volumes, durations, and locations anticipated in the River Walk project. As mentioned at the October meeting, we would need to obtain a new NPDES discharge permit from the Santa Ana Regional Board to allow this new discharge of GWRS water to the SAR.

3. Potential Corrosion. Related to #3, we have experienced some corrosion of our concretemortar lined GWRS Pipeline between Fountain Valley and Anaheim, as well as our recharge basin discharge structures. We have had to repair this damage and begun a multi-phase effort to add an epoxy liner to our pipeline. Given that GWRS water would be in contact with the concrete-lined SAR flood control channel and related structures, as well as new project features such as the rubber dam, we believe that some assessment GWRS water quality compatibility with the project area/features needs to be undertaken.

4. Algae control. We experience regular algae growth at our shallow GWRS recharge basins in Anaheim. We suspect this is due to the low, but detectable, nutrient levels in the water as well as the clarity of the water allowing sunlight to penetrate. Will the River Walk project would seek to control/eliminate algae growth for aesthetic or other purposes? If so, any potential chemical addition, polishing treatment, or other modifications to GWRS water quality would need to be analyzed for impacts on groundwater quality after infiltration (see #2).

5. Creation of new habitat. Will the project’s proposed water impoundment create new wildlife habitat and any associated new obligations for Anaheim and/or OCWD? We understand that some of these items could be addressed outside of CEQA, but felt it was best to bring them to your attention at this time. If you and/or your project team could let us know how/if these issues will be addressed moving forward, we’d be most appreciative.

If you and/or your team would like to discuss any of these items, I’d recommend we setup a time this week for a virtual meeting.

Thanks,
Jason
Jason S. Dadakis, P.G., C.HG
Executive Director Water Quality and Technical Resources Orange County Water District
18700 Ward Street, Fountain Valley, CA 92708
Office: (714) 378-3364
Email: [email protected]
Confidential Communication
OCWD Confidential Communication: This electronic transmission, and any documents attached hereto, (a) are protected by the Electronic Communications Privacy Act (18 USC §§ 2510-2521), (b) may contain confidential information, and (c) are for the sole use of the intended recipient named above. If you have received this electronic message in error, please notify the sender and delete the electronic message. Any disclosure, copying, distribution, or use of the contents of the information received in error is strictly prohibited.

I]
April 20, 2023
Ana Straabe, Principal Project Planner
City of Anaheim, Community Services Department
200 South Anaheim Boulevard, Suite 433
Anaheim, California 92805
Phone: (714) 765-4463
E-mail: [email protected]
RE: SCAG Comments on the Notice of Preparation of a Draft Environmental Impact Report for the OC River Walk Project [SCAG NO. IGR10859]
Dear Ana Straabe,
Thank you for submitting the Notice of Preparation of a Draft Environmental Impact Report for the OC River Walk Project (“proposed project”) to the Southern California Association of Governments (SCAG) for review and comment. SCAG is responsible for providing informational resources to regionally significant plans, projects, and programs per the California Environmental Quality Act (CEQA) to facilitate the consistency of these projects with SCAG’s adopted regional plans, to be determined by the lead agencies.1 Pursuant to Senate Bill (SB) 375, SCAG is the designated Regional Transportation Planning Agency under state law and is responsible for preparation of the Regional Transportation Plan (RTP) including the Sustainable Communities Strategy (SCS). SCAG’s feedback is intended to assist local jurisdictions and project proponents to implement projects that have the potential to contribute to attainment of Regional Transportation Plan/Sustainable Communities Strategy (RTP/SCS) goals and align with RTP/SCS policies. Finally, SCAG is the authorized regional agency for Intergovernmental Review (IGR) of programs proposed for Federal financial assistance and direct Federal development activities, pursuant to Presidential Executive Order 12372.

SCAG staff has reviewed the Notice of Preparation of a Draft Environmental Impact Report for the OC River Walk Project in Orange County. The proposed project includes five major elements to improve the Santa Ana River corridor including river recharge, riverbank modifications, a new pedestrian/bicycle bridge, art and education, and trail extensions and expansions on a 90-acre site.

When available, please email environmental documentation to [email protected] providing, at a minimum, the full public comment period for review.

If you have any questions regarding the attached comments, please contact the Intergovernmental Review (IGR) Program, attn.: Annaleigh Ekman, Senior Regional Planner, at (213) 630-1427 or [email protected]. Thank you.

Sincerely,
Frank Wen, Ph.D.

Manager, Planning Strategy Department
1 Lead agencies such as local jurisdictions have the sole discretion in determining a local project’s consistency with the 2020 RTP/SCS (Connect SoCal) for the purpose of determining consistency for CEQA.

INNOVATING FOR A BETTER TOMORROW

SOUTHERN CALIFORNIA

ASSOCIATION OF GOVERNMENTS
900 Wilshire Blvd., Ste. 1700
Los Angeles, CA 90017
(213) 236-1800
www.scag.ca.gov

REGIONAL COUNCIL OFFICERS
President
Jan C. Harnik, Riverside County
Transportation Commission
First Vice President
Art Brown, Buena Park
Second Vice President
Curt Hagman, County of
San Bernardino
Immediate Past President
Clint Lorimore, Eastvale

COMMITTEE CHAIRS
Executive/Administration
Jan C. Harnik, Riverside County
Transportation Commission
Community, Economic &
Human Development
Frank Yokoyama, Cerritos
Energy & Environment
Deborah Robertson, Rialto
Transportation
Ray Marquez, Chino Hills
April 20, 2023 SCAG No. IGR10859
Ana Straabe Page 2

COMMENTS ON THE NOTICE OF PREPARATION OF A

DRAFT ENVIRONMENTAL IMPACT REPORT FOR THE
OC RIVER WALK PROJECT [SCAG NO. IGR10859]

CONSISTENCY WITH CONNECT SOCAL
SCAG provides informational resources to facilitate the consistency of the proposed project with the adopted 2020-2045 Regional Transportation Plan/Sustainable Communities Strategy (RTP/SCS or Connect SoCal). For the purpose of determining consistency with CEQA, lead agencies such as local jurisdictions have the sole discretion in determining a local project’s consistency with Connect SoCal.

CONNECT SOCAL GOALS
The SCAG Regional Council fully adopted Connect SoCal in September 2020. Connect SoCal, also known as the 2020 – 2045 RTP/SCS, builds upon and expands land use and transportation strategies established over several planning cycles to increase mobility options and achieve a more sustainable growth pattern. The long-range visioning plan balances future mobility and housing needs with goals for the environment, the regional economy, social equity and environmental justice, and public health. The goals included in Connect SoCal may be pertinent to the proposed project.

These goals are meant to provide guidance for considering the proposed project. Among the relevant goals of Connect SoCal are the following:

SCAG CONNECT SOCAL GOALS
Goal #1: Encourage regional economic prosperity and global competitiveness Goal #2: Improve mobility, accessibility, reliability and travel safety for people and goods Goal #3: Enhance the preservation, security, and resilience of the regional transportation system Goal #4: Increase person and goods movement and travel choices within the transportation system Goal #5: Reduce greenhouse gas emissions and improve air quality Goal #6: Support healthy and equitable communities
Goal #7: Adapt to a changing climate and support an integrated regional development pattern and transportation network
Goal #8: Leverage new transportation technologies and data-driven solutions that result in more efficient travel Goal #9: Encourage development of diverse housing types in areas that are supported by multiple transportation options
Goal #10: Promote conservation of natural and agricultural lands and restoration of habitats For ease of review, we encourage the use of a side-by-side comparison of SCAG goals with discussions of the consistency, non-consistency or non-applicability of the goals and supportive analysis in a table format. Suggested format is as follows:

April 20, 2023 SCAG No. IGR10859
Ana Straabe Page 3

SCAG CONNECT SOCAL GOALS
Goal Analysis
Goal #1: Encourage regional economic prosperity and global competitiveness
Consistent: Statement as to why;
Not-Consistent: Statement as to why;
Or
Not Applicable: Statement as to why;
DEIR page number reference
Goal #2: Improve mobility, accessibility, reliability and travel safety for people and goods
Consistent: Statement as to why;
Not-Consistent: Statement as to why;
Or
Not Applicable: Statement as to why;
DEIR page number reference
etc. etc.

Connect SoCal Strategies
To achieve the goals of Connect SoCal, a wide range of land use and transportation strategies are included in the accompanying twenty (20) technical reports. Of particular note are multiple strategies included in Chapter 3 of Connect SoCal intended to support implementation of the regional Sustainable Communities Strategy (SCS) framed within the context of focusing growth near destinations and mobility options; promoting diverse housing choices; leveraging technology innovations; supporting implementation of sustainability policies; and promoting a Green Region. To view Connect SoCal and the accompanying technical reports, please visit the Connect SoCal webpage.

Connect SoCal builds upon the progress from previous RTP/SCS cycles and continues to focus on integrated, coordinated, and balanced planning for land use and transportation that helps the SCAG region strive towards a more sustainable region, while meeting statutory requirements pertinent to RTP/SCSs. These strategies within the regional context are provided as guidance for lead agencies such as local jurisdictions when the proposed project is under consideration.

SCAG staff would like to call your attention to the Water Action Resolution unanimously adopted by SCAG’s Regional Council on October 6, 2022 that formally affirmed the drought and water shortage emergency in Southern California and called on local and regional partners to join together to adopt an “all of the above” approach to addressing the region’s water challenges and catalyzing opportunities. The Resolution calls on SCAG to take action and support partners to reduce water use; improve water conservation, reuse, and efficiency; enhance water systems’ health and resilience; pursue and potentially implement new water supply and storage opportunities; and support investments in water infrastructure and conservation practices that support the region’s economic and population growth and fosters planning for the region’s housing needs.

DEMOGRAPHICS AND GROWTH FORECASTS
A key, formative step in projecting future population, households, and employment through 2045 for Connect SoCal was the generation of a forecast of regional and county level growth in collaboration with expert demographers and economists on Southern California. From there, jurisdictional level forecasts were ground-truthed by subregions and local agencies, which helped SCAG identify opportunities and barriers to future development. This forecast helps the region understand, in a very general sense, where we are expected to grow, and allows SCAG to focus attention on areas that are experiencing change and may have increased transportation needs. After a year-long engagement effort with all 197 jurisdictions one-on-one, 82 percent of SCAG’s 197 jurisdictions provided feedback on the forecast of future growth for Connect SoCal. SCAG also sought feedback on potential sustainable growth strategies from a broad range of stakeholder groups – including local jurisdictions, county transportation commissions, other partner agencies, industry groups, community-based organizations, and the general public. Connect SoCal utilizes a bottomup approach in that total projected growth for each jurisdiction reflects feedback received from jurisdiction staff, including city managers, community development/planning directors, and local staff. Growth at the neighborhood April 20, 2023 SCAG No. IGR10859
Ana Straabe Page 4
level (i.e., transportation analysis zone (TAZ) reflects entitled projects and adheres to current general and specific plan maximum densities as conveyed by jurisdictions (except in cases where entitled projects and development agreements exceed these capacities as calculated by SCAG). Neighborhood level growth projections also feature strategies that help to reduce greenhouse gas emissions (GHG) from automobiles and light trucks to achieve Southern California’s GHG reduction target, approved by the California Air Resources Board (CARB) in accordance with state planning law. Connect SoCal’s Forecasted Development Pattern is utilized for long range modeling purposes and does not supersede actions taken by elected bodies on future development, including entitlements and development agreements. SCAG does not have the authority to implement the plan -- neither through decisions about what type of development is built where, nor what transportation projects are ultimately built, as Connect SoCal is adopted at the jurisdictional level. Achieving a sustained regional outcome depends upon informed and intentional local action. To access jurisdictional level growth estimates and forecasts for years 2016 and 2045, please refer to the Connect SoCal Demographics and Growth Forecast Technical Report. The growth forecasts for the region and applicable jurisdictions are below.

Adopted SCAG Region Wide Forecasts Adopted City of Anaheim Forecasts Year 2020 Year 2030 Year 2035 Year 2045 Year 2020 Year 2030 Year 2035 Year 2045 Population 19,517,731 20,821,171 21,443,006 22,503,899 367,550 389,417 400,265 416,789 Households 6,333,458 6,902,821 7,170,110 7,633,451 105,927 110,666 114,472 122,701 Employment 8,695,427 9,303,627 9,566,384 10,048,822 200,992 220,681 230,637 250,544

MITIGATION MEASURES
SCAG staff recommends that you review the Final Program Environmental Impact Report (Final PEIR) for Connect SoCal for guidance, as appropriate. SCAG’s Regional Council certified the PEIR and adopted the associated Findings of Fact and a Statement of Overriding Considerations (FOF/SOC) and Mitigation Monitoring and Reporting Program (MMRP) on May 7, 2020 and also adopted a PEIR Addendum and amended the MMRP on September 3, 2020 (please see the PEIR webpage and scroll to the bottom of the page for the PEIR Addendum). The PEIR includes a list of project-level performance standards-based mitigation measures that may be considered for adoption and implementation by lead, responsible, or trustee agencies in the region, as applicable and feasible. Project-level mitigation measures are within responsibility, authority, and/or jurisdiction of project-implementing agency or other public agency serving as lead agency under CEQA in subsequent project- and site- specific design, CEQA review, and decision-making processes, to meet the performance standards for each of the CEQA resource categories.

May 8, 2023
Ana Straabe
Principal Project Planner
City of Anaheim, Community Development Department, Parks 200 S. Anaheim Boulevard, Suite 433
Anaheim, California 92805
Subject: Notice of Preparation of a Draft Environmental Impact Report for the OC River Walk Project
Dear Ana Straabe,
Thank you for the opportunity to comment on the Notice of Preparation of a Draft Environmental Impact Report (EIR) for the OC River Walk Project (Project).

Since the primary function of the Santa Ana River Channel and its levees (collectively the Channel) is to provide flood protection to the residents of Orange County, any potential impacts to and other issues related to this Channel will be analyzed and evaluated during the review of the EIR and during the application for an encroachment permit from the Orange County Flood Control District (OCFCD). These would include, but not limited to the following: a) hydrology and hydraulics, b) structural design of the proposed channel improvements, c) proposed landscaping, d) scour study, e) proposed trail design, f) operation and maintenance of the Channel, g) ownership, operation, and maintenance of the proposed features, h) public safety, i) security within the project area, j) right-of-way acquisition, k) agreements among various agencies, such as the U.S. Army Corps of Engineers (USACE) Section 408 permit application, etc. Since the Project proposal has not sufficiently progressed in obtaining a Section 408 permit for the proposed improvements on the Channel, insufficient data is available to analyze the Initial Study.

It is premature to sufficiently assess all impacts and would need to be addressed in an EIR to consider appropriate mitigation. OCFCD reserves the right to require additional analyses and assurances from the City of Anaheim (City) as project proponent to protect OCFCD and County of Orange (County) from increased fiscal obligations, liability, and risk, before committing to any of the Project proposals which rely upon use of OCFCD land and/or facilities or any County or OCFCD resources.

The comments and requirements herein are not all inclusive, additional requirements may be added during the encroachment permit review of detailed submittals.

The County review during the permit process is generally limited to the acceptability of the concept, and while all County requirements should be addressed during the final design of the project, the final design should generally adhere to the concept (i.e., no major deviations).

ATTACHMENT Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C Counfy Adminisfrafion South
601 North Ross S1reet
Santa Ana, CA 92701
P.O. Box 4048
Santa Ana. CA 92702
(714) 667-8800
info@ocpw .ocgov .com
OCPublicWorks.com
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" OAA N GE COUNTY
OCPublic Works
NCL23-0003
May 8, 2023
601 North Ross Street, Santa Ana, CA 92701
P.O. Box 4048, Santa Ana, CA 92702-4048
www.OCPublicWorks.com
(714) 667-8800 | [email protected]

The County offers the following comments for your consideration.

OC Flood Programs/Floodplain Management:

Engineering:

1. Hydrology and Hydraulics – design standards will meet USACE and OCFCD criteria including levee design, vegetation, freeboard, etc. The Channel is designed to function and accommodate flows as part of the Santa Ana River Mainstem (SARM) system that includes Prado Dam, Prado Basin, Seven Oaks Dam and various dike features.

2. Impoundment of water must demonstrate no impact to local drainage and/or interior drainage to the surrounding areas during any storm events. Explain and address any effects of the impoundment on the Collins Channel (OCFCD Facility No. E07). This channel contains deficient segments that may require future improvements. The potential development should not worsen the existing conditions or shift flooding deficiencies to this channel. Similarly, please explain how these improvements would impact the Chantilly Storm Channel (OCFCD Facility No. E01S02). Further discussions are also needed for the proposed structures for urban storm water treatment and their effects on the functions of these flood control facilities.

3. Structural and Bridges – design standards will meet USACE and OCFCD criteria including freeboard, scour, debris, etc. Improvements and structures will need to withstand the velocity of the water from Prado Dam releases.

Construction:

1. Project will require OCFCD Encroachment, Section 408 and 404 Permits. Prior to OCFCD’s participation in the Section 408 Permit process, the cities of Anaheim and Orange are required to enter into a cooperative agreement with OCFCD and OC Parks for the OC River Walk Project, which will be approved and executed by an authorized representative of the County of Orange Board of Supervisors.

2. Temporary Construction Easements needs to be identified and secured for the duration of the project.

3. A flood contingency plan will be required for review and approval by OCFCD and USACE.

Public Services Impacts:

1. The Project has features proposed within areas of the Channel that are owned by OCFCD and that are outside of public right-of-way. These areas are currently not publicly accessible due to concerns for safety, hazard prevention and public health. The Initial Study should mention that the public is not authorized to be on the Channel’s grouted riprap currently, as it would be considered trespassing and hazardous.

2. The Initial Study also did not acknowledge the need to analyze the Project impacts on public services.

Due to the Project increasing accessibility to the public on the Channel, it is appropriate for the EIR to analyze an increased reliance on local police and reflect that the respective cities’ police forces will mitigate such impacts by perhaps increasing personnel, increasing patrols, improving lighting, taking efforts to prevent overnight encampments, perform debris and graffiti removal.

Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C NCL23-0003
May 8, 2023

601 North Ross Street, Santa Ana, CA 92701
P.O. Box 4048, Santa Ana, CA 92702-4048
www.OCPublicWorks.com
(714) 667-8800 | [email protected]

3. Similarly due to the Project increasing accessibility to the public on the Channel, it is appropriate for the EIR to analyze impacts to performance of flood control and protection activities. The existing Channel is currently eligible for Public Law 84-99 program coverage. When flood conditions exceed, or are predicted to exceed, the response capability of levee and drainage districts and local or state governments, the USACE has the authority under Public Law 84-99 to provide emergency flood response assistance without further specific authorization of Congress. The USACE can furnish assistance for flood emergency preparation, flood fighting, and the repair and restoration of certain flood damage reduction projects damaged or destroyed by flood. Assistance also includes providing flood fighting personnel for technical advice, sandbags, plastic sheeting, pumps, or other materials and equipment for an imminent or actual flood emergency to protect against substantial loss of life and property. The City will need to ensure that the Project will not change the Channel’s Public Law 84-99 eligibility status and ensure that the City will be responsible for any flood control feature replacements not covered by PL 84-99.

Right of Way:

1. Permittee is required to identify ROW needed for the project construction phase and post construction, if any. The City will need to offer to purchase from OCFCD ROW necessary for the Project based upon a market appraisal, and acquire said rights, interest or authorizations to use of OCFCD land and/or facilities prior to commencing work for the Project on OCFCD land and/or facilities. Any ROW interest or use agreement with include terms for the City to be fully responsible for any increased fiscal obligations incurred by OCFCD or the County and shall include indemnification and hold harmless terms for City to assume all liability and risk associated with the Project. Each ROW document and agreement will include terms stating that the primary function of the Channel is flood control for SARM system that serves other counties upstream. As it may be found inappropriate for the Project to hinder receipt of water flows in a storm event, impacting communities all along the Channel, the EIR will need to show it is not offending basic water rights.

2. Any proposed bridges for the Project may require new bridge and highway easement(s) and/or other ROW agreement that the City would be responsible for the operation and maintenance of said bridge, including pier noses and footings, and that City will be responsible for any damages to flood features caused by the structure’s presence in the Channel.

Operations & Maintenance:

1. The Santa Ana River’s primary function is flood control; therefore, the permittee will be required to operate and maintain all functions of the OC River Walk components, including but not limited to, any levee bank modifications/benches, vegetation, trails, bridges, water impoundment features, lighting, access to and from trails, fencing, gates, etc.

2. Permittee is required to enter into a cooperative agreement with OCFCD and OC Parks and/or a Lease Agreement with OCFCD for the use of OC River Walk.

3. A flood contingency plan may be required to address water impoundment and unexpected release(s) from Prado Dam.

Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C NCL23-0003
May 8, 2023

601 North Ross Street, Santa Ana, CA 92701
P.O. Box 4048, Santa Ana, CA 92702-4048
www.OCPublicWorks.com
(714) 667-8800 | [email protected]
Environmental:

1. What are the environmental and hydrological impacts of multiple impoundments operating at same time?

2. Any and all resource agency or regulatory permits, agreements, or other instruments which may impact OCFCD must be approved prior by the Director of OC Public Works. City shall obtain reasonable and appropriate regulatory advance guidance on approved “safe harbor” performance allowable for all stages of the Project and when applicable, make earnest effort to facilitate agreements with specific regulatory agencies, such as a Lake or Streambed Alteration Agreement or California Endangered Species Act Incidental Take Permit, to safeguard District regarding liability issues for Channel operation and maintenance impacted by the Project.

3. Address any public health concerns regarding recreational use of the water in the Channel; include water quality and post-storm event procedures in an Operation and Maintenance Manual provided to OCFCD via encroachment permit for review and approval.

4. An assessment should be carried out to identify specific opportunities that can be incorporated into the Project to benefit wildlife and specifically wildlife that relies upon riverine and riparian conditions. For example, there are opportunities to: 1) include vegetated bioengineered solutions on the riverbank to encourage native vegetation rather than just reinforcing the slopes with hard engineering solutions. 2) provide better connectivity to adjacent basins to improve habitat for wildlife,3) establish better quality in channel habitats at the upper limits of the proposed impoundments, as the water becomes shallow, potentially with a reduced need to entrain the river for recharge if greater recharge is occurring in the basins. The assessment should consider these and other habitat and environmental improvement opportunities. The LA River Master Plan is a good reference for identifying and incorporating multifunctional benefits into a development such as this.

River bank modifications:

1. There is a significant opportunity for this Project to enhance the biological diversity of the river and especially the river banks in a manner that is conducive with the wider aims of the Project. Section

1.4.1.2 only discusses hard engineering solutions for bank modifications. There is an opportunity to utilize both hard engineering solutions and soft bio-engineering solutions to create attractive riparian vegetated areas, provide habitat for wildlife and can help with water quality treatment.

Urban Stormwater Treatment:

1. Information on the urban stormwater treatment is vague. Is this in reference to an Irvine Ranch Water District San Joaquin Marsh style natural water treatment system? There is also the opportunity to utilize low impact development (LID) techniques to treat storm and dry weather runoff along and adjacent to the trail. There is also the potential to allow more native vegetation to grow in the channel itself outside of the impounded reaches. Vegetation can help to improve water quality, as well as providing habitat for wildlife and is visually appealing. If a Safe Harbor Agreement is established for this development any vegetation could be managed as needed for flood and other purposes without falling afoul of endangered species legislation.

Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C NCL23-0003
May 8, 2023

601 North Ross Street, Santa Ana, CA 92701
P.O. Box 4048, Santa Ana, CA 92702-4048
www.OCPublicWorks.com
(714) 667-8800 | [email protected]

5. Section 2.4.15 Public Services – Additional substantiation should be included to confirm fire and police services can maintain acceptable service ratios, response times or other performance objectives with the “influx of local community and tourists”.

6. Section 2.4.17 Transportation - The project should evaluate how the anticipated influx of local community and tourist will affect or interfere with an adopted emergency responses plan or emergency evacuation plan. In addition, the project description should include the anticipated number of trips for construction and operation generated by the Proposed Project. Specifically, the analysis should evaluate whether the number of existing off-street parking facilities can accommodate the anticipated influx of local community and tourist.

OC Environmental Resources:

1. Projects that, as part of a common plan of development, disturb one or more acres are required to obtain coverage under the General Permit for Discharges of Storm Water Associated with Construction Activity, Order 2009-0009-DWQ (and subsequent Order 2022-0057-DWQ) and implement a Storm Water Pollution Prevention Plan (SWPPP) and monitoring program consistent with permit requirements.

2. Specific mention should be made of whether the project qualifies as a Priority Development Project under the city’s municipal stormwater permit (Santa Ana Regional Board Order R8-2009-0030), or instead is a Non-Priority Project which would require preparation of a Non-Priority Water Quality Project Plan.

3. New development projects that create 10,000 square feet or more of impervious surface require the development of a Water Quality Management Plan (WQMP). Specific mention should be made of applicable city WQMP requirements for projects to comply with their municipal stormwater permits.

4. Specific mention should be made of the Orange County Stormwater Program’s Drainage Area Management Plan (DAMP). The DAMP is Orange County’s principal policy and program guidance document for stormwater management and includes a 2017 Technical Guidance Document to be followed in preparing the project’s WQMP.

5. Specific mention should be made of the potential water quality impacts from the Proposed Project and identification of the anticipated pollutants to be generated or mobilized by the project should be provided.

6. In collaboration with the Orange County Water District (OCWD) and the OC Sanitation District (OC San) efforts to minimize urban runoff impacts to Orange County waters, OC Public Works continues to research low-flow, dry-weather season diversion project opportunities. OC Public Works is participating in the OC San Urban Runoff Optimization Study, which will identify, evaluate, and develop additional urban runoff diversion opportunities. Should any potential sanitary sewer diversions be considered for the surrounding storm drains around the OC River Walk Project, a permit from OC San would be required along with coordination with the Orange County Stormwater Program’s Technical Advisory Committee (TAC), which is administered by OC Environmental Resources. Diverted urban flows that are discharged into the sanitary sewer system would also be counted towards the collective 10 million Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C NCL23-0003
May 8, 2023

601 North Ross Street, Santa Ana, CA 92701
P.O. Box 4048, Santa Ana, CA 92702-4048
www.OCPublicWorks.com
(714) 667-8800 | [email protected]
gallons per day fee-waived allowance that is shared among the Orange County Permittees (County of Orange, Orange County Flood Control District (OCFCD), and cities). Other types of diversion projects, such as the Chantilly storm drain to Burris Basin, should also be coordinated with OC Public Works and potentially the Orange County Stormwater Program’s Watershed Improvement Projects Subcommittee (WIPS) referenced in the project’s engineering feasibility study.

7. The OC River Walk Project is supplied by treated water from the OCWD’s Groundwater Replenishment System that will be discharged into the Santa Ana River. National Pollution Discharge Elimination System (NPDES) permitting is anticipated to be required from the Santa Ana Regional Water Quality Control Board such as through an individual NPDES permit or other de minimis discharge permit. The discharge operations for the project and associated NPDES permit should be coordinated with OCFCD through the encroachment permit, in addition to other impacted regulatory agencies.

8. The project should evaluate how large high-flow offsite discharges, such as an emergency response from a fire, sanitary sewer release, illegal discharge, or water main break, would be addressed in the surrounding drainages if diverted or cut off from the Santa Ana River. For example, a large-scale fire and multi-agency water pollution response event occurred in this reach of the Santa Ana River in February 2022.

OC Parks:

Trail and Adjacent Areas:

1. All costs and responsibilities for OC River Walk elements that are proposed on County property, including but not limited to planning, permitting, construction, operation, maintenance and public safety, shall be borne by the City, and be fully compatible with flood control requirements and subject to a land lease acceptable to and approved by the Orange County Board of Supervisors.

2. The term “alternative modes of transportation” is used throughout the document as something encouraged on the trails through the project area but is not defined. In the event this is intended to include motorized modes of transit such as e-bikes and e-scooters, it should be noted that on this portion of the trail system only Class 1 and 2 e-bikes are permitted.

3. The “Active (AT) Transportation” improvements described as it relates to the Santa Ana River Trail (SART) and other proposed trail segments is not well defined, so additional detail is needed, including defined conceptual development plans to identify/depict those improvements, to understand the impact of those improvements.

4. Additional detail is needed on which trail areas are proposed to be expanded to understand the level of physical impact that would occur within the trail areas, in order for the County to comment as it relates to our existing easements.

5. Additional detail is needed on the new pedestrian bridge identified that provides bike and pedestrian access across the river, as it is not clear how this bridge will interface with the existing trail locations.

6. Landscaping enhancement is identified as being a component of the project, but it is not clear what the enhancement will include and in what areas landscaping would be occurring as it is not defined in the Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C NCL23-0003
May 8, 2023

601 North Ross Street, Santa Ana, CA 92701
P.O. Box 4048, Santa Ana, CA 92702-4048
www.OCPublicWorks.com
(714) 667-8800 | [email protected]
plan. Additional detail regarding how the City will address this is needed for OC Parks to provide necessary feedback.

7. Placing the SART on the East levee South of Katella to Orangewood may cause concern for multiple agencies. The service road is heavily used by OC Public Works (OCPW), OC Flood Control District (OCFCD), OC Watershed, OC Sheriff, and other agencies and contractors that utilize the Collins Yard, the OCFCD Storage yard, the OCPW and OC Parks SART Storage facility, and the OC Sheriff Training Facility. The East side, due to its heavy utilization as a service road, generates concerns related to incompatible use and potential safety concerns.

8. It is important for the City to address unwanted activities related to security, debris removal, and transient management as it relates to the addition of features accessible to the public and plan methods to minimize those impacts.

9. Additional detail is needed on the proposed new trail areas and how additional improvement to the existing trail will interface with the surrounding uses, for the County to provide necessary feedback.

10. Operating hours for the River Walk were not identified. The SART is closed at sunset, therefore if the design will encourage or allow use of the trail system outside the existing hours of operation, the City would need to make considerations for operating the River Walk that would take that into account.

If you have any questions regarding this comment, please contact Yuritzy Randle at (714) 667-8816 in OC Development Services, Giatho Tran at (714)-647-3972 or Ariel Corpuz at (714) 647-3966 in OC Floods Programs, Tracey Ingebrigtsen at (714) 955-0687 in OC Environmental Resources, or Brian Kurnow at (949) 585-6446 in OC Parks.

Please continue to keep the County of Orange on the distribution list for future notifications related to the Project.

Sincerely,
Cindy Salazar, Land Use Manager
OC Public Works /OC Development Services
601 North Ross Street
Santa Ana, California 92701
[email protected]
cc: Justin Kirk, Deputy Director, OC Development Services Nardy Khan, PE/PMP, Deputy Director, OC Infrastructure Programs Giatho Tran, P.E., C.F.M., Senior Civil Engineer, OC Flood Programs Ariel Corpuz, P.E., Senior Civil Engineer, OC Flood Programs Tracey Ingebrigtsen CPESC®, QSD/QSP, Countywide Compliance Program Manager, OC Environmental Resources
Brian Kurnow, Interim Planning & Design Division Manager, OC Parks Yuritzy Randle, Associate Planner, OC Development Services Docusign Envelope ID: 32180788-A34B-4AE9-9903-C9350274352C t b

Appendix C. Air Quality/GHG Data
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OC Riverwalk 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

3. Construction Emissions Details

3.1. Linear, Grubbing & Land Clearing (2026) - Unmitigated

3.3. Linear, Grading & Excavation (2026) - Unmitigated

3.5. Linear, Grading & Excavation (2027) - Unmitigated

3.7. Linear, Drainage, Utilities, & Sub-Grade (2027) - Unmitigated

3.9. Linear, Drainage, Utilities, & Sub-Grade (2028) - Unmitigated

3.11. Linear, Paving (2028) - Unmitigated

4. Operations Emissions Details
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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

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 OC Riverwalk Detailed Report, 2/4/2025
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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

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
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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 OC Riverwalk
Construction Start Date 6/1/2026
Lead Agency —
Land Use Scale Project/site
Analysis Level for Defaults County
Windspeed (m/s) 1.80
Precipitation (days) 18.2
Location 33.80935537073766, -117.87516322656214
County Orange
City Anaheim
Air District South Coast AQMD
Air Basin South Coast
TAZ 5706
EDFZ 7
Electric Utility City of Anaheim Public Utilities Department Gas Utility Southern California Gas
App Version 2022.1.1.29

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
Bridge/Overpass
Construction

0.14 Mile 0.68 0.00 — — — Bridges
Road Construction 3.56 Mile 33.1 0.00 — — — Trail
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User Defined Linear 1.05 Mile 0.59 0.00 — — — Retaining Walls User Defined Linear 0.15 Mile 3.30 0.00 0.00 — — Impoundment structure

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. ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Unmit. 9.29 77.7 92.7 0.19 3.33 7.62 11.0 3.07 1.03 4.10 — 22,660 22,660 0.93 0.43 7.35 22,818 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Unmit. 9.29 77.8 92.0 0.19 3.33 7.62 11.0 3.07 1.03 4.10 — 22,598 22,598 0.93 0.43 0.19 22,749 Average
Daily
(Max)
— — — — — — — — — — — — — — — — —
Unmit. 5.53 45.6 56.0 0.12 1.85 4.95 6.80 1.70 0.66 2.36 — 14,288 14,288 0.59 0.25 1.70 14,378 Annual
(Max)
— — — — — — — — — — — — — — — — —
Unmit. 1.01 8.32 10.2 0.02 0.34 0.90 1.24 0.31 0.12 0.43 — 2,365 2,365 0.10 0.04 0.28 2,380

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 ROG NOx CO SO2 PM10E PM10D PM10T PM2.5E PM2.5D PM2.5T BCO2 NBCO2 CO2T CH4 N2O R CO2e ------------------
------------------
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Daily -
Summer
(Max)
— — — — — — — — — — — — — — — — —
2026 9.29 77.7 92.7 0.19 3.33 7.62 11.0 3.07 1.03 4.10 — 22,660 22,660 0.93 0.43 7.35 22,818 2027 8.88 72.4 92.0 0.19 3.03 7.62 10.7 2.79 1.03 3.82 — 22,611 22,611 0.93 0.43 6.67 22,768 2028 1.44 12.4 21.8 0.03 0.42 2.85 3.27 0.39 0.37 0.76 — 3,582 3,582 0.13 0.03 1.76 3,597 Daily -
Winter
(Max)
— — — — — — — — — — — — — — — — —
2026 9.29 77.8 92.0 0.19 3.33 7.62 11.0 3.07 1.03 4.10 — 22,598 22,598 0.93 0.43 0.19 22,749 2027 8.88 72.4 91.3 0.19 3.03 7.62 10.7 2.79 1.03 3.82 — 22,549 22,549 0.93 0.43 0.17 22,700 2028 6.33 51.2 63.9 0.15 1.97 6.48 8.44 1.81 0.83 2.64 — 17,267 17,267 0.70 0.26 0.10 17,363 Average
Daily
— — — — — — — — — — — — — — — — —
2026 2.70 22.9 26.9 0.06 0.98 2.55 3.53 0.90 0.35 1.25 — 6,730 6,730 0.29 0.17 1.20 6,788 2027 5.53 45.6 56.0 0.12 1.85 4.95 6.80 1.70 0.66 2.36 — 14,288 14,288 0.59 0.25 1.70 14,378 2028 0.82 6.76 9.75 0.02 0.25 1.09 1.34 0.23 0.14 0.37 — 2,147 2,147 0.08 0.03 0.30 2,159 Annual — — — — — — — — — — — — — — — — —
2026 0.49 4.18 4.91 0.01 0.18 0.47 0.64 0.16 0.06 0.23 — 1,114 1,114 0.05 0.03 0.20 1,124 2027 1.01 8.32 10.2 0.02 0.34 0.90 1.24 0.31 0.12 0.43 — 2,365 2,365 0.10 0.04 0.28 2,380 2028 0.15 1.23 1.78 < 0.005 0.05 0.20 0.24 0.04 0.03 0.07 — 356 356 0.01 0.01 0.05 358

3. Construction Emissions Details

3.1. Linear, Grubbing & Land Clearing (2026) - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location 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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Off-Road
Equipment

0.83 7.26 7.97 0.01 0.40 — 0.40 0.37 — 0.37 — 1,122 1,122 0.05 0.01 — 1,126 Dust
From
Material
Movement
— — — — — 0.42 0.42 — 0.05 0.05 — — — — — — —
Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.5 26.5 < 0.005 < 0.005 0.04 27.9 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Average
Daily
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.12 1.03 1.14 < 0.005 0.06 — 0.06 0.05 — 0.05 — 160 160 0.01 < 0.005 — 160 Dust
From
Material
Movement
— — — — — 0.06 0.06 — 0.01 0.01 — — — — — — —
Onsite
truck
< 0.005 0.01 0.01 < 0.005 < 0.005 0.30 0.30 < 0.005 0.03 0.03 — 3.77 3.77 < 0.005 < 0.005 < 0.005 3.97 Annual — — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.02 0.19 0.21 < 0.005 0.01 — 0.01 0.01 — 0.01 — 26.5 26.5 < 0.005 < 0.005 — 26.6 Dust
From
Material
Movement
— — — — — 0.01 0.01 — < 0.005 < 0.005 — — — — — — —
Onsite
truck
< 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.06 0.06 < 0.005 0.01 0.01 — 0.62 0.62 < 0.005 < 0.005 < 0.005 0.66 Offsite — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.10 0.09 1.58 0.00 0.00 0.39 0.39 0.00 0.09 0.09 — 391 391 < 0.005 0.01 1.36 396 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 OC Riverwalk Detailed Report, 2/4/2025
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Hauling 0.03 2.28 1.01 0.01 0.02 0.50 0.53 0.02 0.14 0.17 — 1,911 1,911 0.15 0.30 3.87 2,008 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Average
Daily
— — — — — — — — — — — — — — — — —
Worker 0.01 0.01 0.20 0.00 0.00 0.06 0.06 0.00 0.01 0.01 — 53.7 53.7 < 0.005 < 0.005 0.08 54.4 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 Hauling < 0.005 0.34 0.14 < 0.005 < 0.005 0.07 0.07 < 0.005 0.02 0.02 — 272 272 0.02 0.04 0.24 286 Annual — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 0.04 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 8.89 8.89 < 0.005 < 0.005 0.01 9.01 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 Hauling < 0.005 0.06 0.03 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 — 45.1 45.1 < 0.005 0.01 0.04 47.3

3.3. Linear, Grading & Excavation (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location 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-Road
Equipment

8.93 75.7 86.7 0.18 3.32 — 3.32 3.05 — 3.05 — 19,970 19,970 0.81 0.16 — 20,039 Dust
From
Material
Movement
— — — — — 3.72 3.72 — 0.40 0.40 — — — — — — —
Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.5 26.5 < 0.005 < 0.005 0.04 27.9 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
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Off-Road
Equipment

8.93 75.7 86.7 0.18 3.32 — 3.32 3.05 — 3.05 — 19,970 19,970 0.81 0.16 — 20,039 Dust
From
Material
Movement
— — — — — 3.72 3.72 — 0.40 0.40 — — — — — — —
Onsite
truck
< 0.005 0.08 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.6 26.6 < 0.005 < 0.005 < 0.005 27.9 Average
Daily
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

2.47 20.9 23.9 0.05 0.91 — 0.91 0.84 — 0.84 — 5,510 5,510 0.22 0.04 — 5,529 Dust
From
Material
Movement
— — — — — 1.03 1.03 — 0.11 0.11 — — — — — — —
Onsite
truck
< 0.005 0.02 0.01 < 0.005 < 0.005 0.58 0.58 < 0.005 0.06 0.06 — 7.31 7.31 < 0.005 < 0.005 < 0.005 7.69 Annual — — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.45 3.81 4.36 0.01 0.17 — 0.17 0.15 — 0.15 — 912 912 0.04 0.01 — 915 Dust
From
Material
Movement
— — — — — 0.19 0.19 — 0.02 0.02 — — — — — — —
Onsite
truck
< 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.11 0.11 < 0.005 0.01 0.01 — 1.21 1.21 < 0.005 < 0.005 < 0.005 1.27 Offsite — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.34 0.30 5.27 0.00 0.00 1.31 1.31 0.00 0.31 0.31 — 1,302 1,302 0.02 0.05 4.53 1,321 Vendor < 0.005 0.06 0.03 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 62.7 62.7 < 0.005 0.01 0.16 65.6 Hauling 0.02 1.55 0.68 0.01 0.02 0.34 0.36 0.02 0.10 0.11 — 1,296 1,296 0.10 0.21 2.62 1,362 OC Riverwalk Detailed Report, 2/4/2025
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Daily, — — — — — — — — — — — — — — — — —
Winter
(Max)
Worker 0.34 0.35 4.55 0.00 0.00 1.31 1.31 0.00 0.31 0.31 — 1,239 1,239 0.02 0.05 0.12 1,254 Vendor < 0.005 0.07 0.03 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 62.8 62.8 < 0.005 0.01 < 0.005 65.5 Hauling 0.02 1.60 0.69 0.01 0.02 0.34 0.36 0.02 0.10 0.11 — 1,296 1,296 0.10 0.21 0.07 1,360 Average
Daily
— — — — — — — — — — — — — — — — —
Worker 0.09 0.10 1.30 0.00 0.00 0.36 0.36 0.00 0.08 0.08 — 347 347 < 0.005 0.01 0.54 351 Vendor < 0.005 0.02 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 17.3 17.3 < 0.005 < 0.005 0.02 18.1 Hauling 0.01 0.45 0.19 < 0.005 < 0.005 0.09 0.10 < 0.005 0.03 0.03 — 358 358 0.03 0.06 0.31 375 Annual — — — — — — — — — — — — — — — — —
Worker 0.02 0.02 0.24 0.00 0.00 0.07 0.07 0.00 0.02 0.02 — 57.4 57.4 < 0.005 < 0.005 0.09 58.1 Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 2.87 2.87 < 0.005 < 0.005 < 0.005 2.99 Hauling < 0.005 0.08 0.03 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 59.2 59.2 < 0.005 0.01 0.05 62.2

3.5. Linear, Grading & Excavation (2027) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location 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-Road
Equipment

8.57 70.4 86.3 0.18 3.02 — 3.02 2.77 — 2.77 — 19,970 19,970 0.81 0.16 — 20,039 Dust
From
Material
Movement
— — — — — 3.72 3.72 — 0.40 0.40 — — — — — — —
Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.0 26.0 < 0.005 < 0.005 0.04 27.4 ------------------
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Daily, — — — — — — — — — — — — — — — — —
Winter
(Max)
Off-Road
Equipment

8.57 70.4 86.3 0.18 3.02 — 3.02 2.77 — 2.77 — 19,970 19,970 0.81 0.16 — 20,039 Dust
From
Material
Movement
— — — — — 3.72 3.72 — 0.40 0.40 — — — — — — —
Onsite
truck
< 0.005 0.08 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.1 26.1 < 0.005 < 0.005 < 0.005 27.5 Average
Daily
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

3.14 25.8 31.6 0.07 1.10 — 1.10 1.02 — 1.02 — 7,308 7,308 0.30 0.06 — 7,333 Dust
From
Material
Movement
— — — — — 1.36 1.36 — 0.15 0.15 — — — — — — —
Onsite
truck
< 0.005 0.03 0.02 < 0.005 < 0.005 0.77 0.77 < 0.005 0.08 0.08 — 9.52 9.52 < 0.005 < 0.005 0.01 10.0 Annual — — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.57 4.70 5.76 0.01 0.20 — 0.20 0.19 — 0.19 — 1,210 1,210 0.05 0.01 — 1,214 Dust
From
Material
Movement
— — — — — 0.25 0.25 — 0.03 0.03 — — — — — — —
Onsite
truck
< 0.005 0.01 < 0.005 < 0.005 < 0.005 0.14 0.14 < 0.005 0.01 0.01 — 1.58 1.58 < 0.005 < 0.005 < 0.005 1.66 Offsite — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.29 0.30 4.94 0.00 0.00 1.31 1.31 0.00 0.31 0.31 — 1,280 1,280 0.01 0.05 4.06 1,299 Vendor < 0.005 0.06 0.03 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 61.6 61.6 < 0.005 0.01 0.15 64.3 OC Riverwalk Detailed Report, 2/4/2025
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Hauling 0.02 1.50 0.67 0.01 0.02 0.34 0.36 0.02 0.10 0.11 — 1,271 1,271 0.10 0.21 2.42 1,337 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.28 0.31 4.25 0.00 0.00 1.31 1.31 0.00 0.31 0.31 — 1,218 1,218 0.02 0.05 0.11 1,233 Vendor < 0.005 0.06 0.03 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 0.01 — 61.6 61.6 < 0.005 0.01 < 0.005 64.2 Hauling 0.02 1.56 0.67 0.01 0.02 0.34 0.36 0.02 0.10 0.11 — 1,271 1,271 0.10 0.21 0.06 1,335 Average
Daily
— — — — — — — — — — — — — — — — —
Worker 0.10 0.13 1.62 0.00 0.00 0.47 0.47 0.00 0.11 0.11 — 452 452 0.01 0.02 0.64 458 Vendor < 0.005 0.02 0.01 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 — 22.5 22.5 < 0.005 < 0.005 0.02 23.5 Hauling 0.01 0.57 0.25 < 0.005 0.01 0.12 0.13 0.01 0.03 0.04 — 465 465 0.04 0.08 0.38 489 Annual — — — — — — — — — — — — — — — — —
Worker 0.02 0.02 0.30 0.00 0.00 0.09 0.09 0.00 0.02 0.02 — 74.8 74.8 < 0.005 < 0.005 0.11 75.8 Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 3.73 3.73 < 0.005 < 0.005 < 0.005 3.89 Hauling < 0.005 0.10 0.04 < 0.005 < 0.005 0.02 0.02 < 0.005 0.01 0.01 — 77.0 77.0 0.01 0.01 0.06 80.9

3.7. Linear, Drainage, Utilities, & Sub-Grade (2027) - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location 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-Road
Equipment

6.31 53.6 61.0 0.15 2.11 — 2.11 1.95 — 1.95 — 15,739 15,739 0.64 0.13 — 15,793 Dust
From
Material
Movement
— — — — — 3.10 3.10 — 0.34 0.34 — — — — — — —
Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.0 26.0 < 0.005 < 0.005 0.04 27.4 ------------------
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Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

6.31 53.6 61.0 0.15 2.11 — 2.11 1.95 — 1.95 — 15,739 15,739 0.64 0.13 — 15,793 Dust
From
Material
Movement
— — — — — 3.10 3.10 — 0.34 0.34 — — — — — — —
Onsite
truck
< 0.005 0.08 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 26.1 26.1 < 0.005 < 0.005 < 0.005 27.5 Average
Daily
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

2.20 18.7 21.2 0.05 0.74 — 0.74 0.68 — 0.68 — 5,482 5,482 0.22 0.04 — 5,501 Dust
From
Material
Movement
— — — — — 1.08 1.08 — 0.12 0.12 — — — — — — —
Onsite
truck
< 0.005 0.03 0.02 < 0.005 < 0.005 0.74 0.74 < 0.005 0.07 0.07 — 9.06 9.06 < 0.005 < 0.005 0.01 9.55 Annual — — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.40 3.41 3.88 0.01 0.13 — 0.13 0.12 — 0.12 — 908 908 0.04 0.01 — 911 Dust
From
Material
Movement
— — — — — 0.20 0.20 — 0.02 0.02 — — — — — — —
Onsite
truck
< 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.13 0.13 < 0.005 0.01 0.01 — 1.50 1.50 < 0.005 < 0.005 < 0.005 1.58 Offsite — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.21 0.22 3.71 0.00 0.00 0.98 0.98 0.00 0.23 0.23 — 960 960 0.01 0.04 3.04 974 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 OC Riverwalk Detailed Report, 2/4/2025
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Hauling 0.01 0.73 0.32 < 0.005 0.01 0.17 0.17 0.01 0.05 0.05 — 617 617 0.05 0.10 1.18 649 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.21 0.23 3.19 0.00 0.00 0.98 0.98 0.00 0.23 0.23 — 914 914 0.01 0.04 0.08 925 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 Hauling 0.01 0.76 0.33 < 0.005 0.01 0.17 0.17 0.01 0.05 0.05 — 618 618 0.05 0.10 0.03 648 Average
Daily
— — — — — — — — — — — — — — — — —
Worker 0.07 0.09 1.16 0.00 0.00 0.34 0.34 0.00 0.08 0.08 — 323 323 < 0.005 0.01 0.46 327 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 Hauling < 0.005 0.27 0.11 < 0.005 < 0.005 0.06 0.06 < 0.005 0.02 0.02 — 215 215 0.02 0.03 0.18 226 Annual — — — — — — — — — — — — — — — — —
Worker 0.01 0.02 0.21 0.00 0.00 0.06 0.06 0.00 0.01 0.01 — 53.4 53.4 < 0.005 < 0.005 0.08 54.1 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 Hauling < 0.005 0.05 0.02 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 — 35.6 35.6 < 0.005 0.01 0.03 37.4

3.9. Linear, Drainage, Utilities, & Sub-Grade (2028) - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location 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-Road
Equipment

6.11 50.2 60.5 0.15 1.96 — 1.96 1.80 — 1.80 — 15,737 15,737 0.64 0.13 — 15,791 ------------------
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Dust — — — — — 3.10 3.10 — 0.34 0.34 — — — — — — —
From
Material
Movement
Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 25.5 25.5 < 0.005 < 0.005 < 0.005 26.9 Average
Daily
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.49 4.03 4.86 0.01 0.16 — 0.16 0.14 — 0.14 — 1,263 1,263 0.05 0.01 — 1,267 Dust
From
Material
Movement
— — — — — 0.25 0.25 — 0.03 0.03 — — — — — — —
Onsite
truck
< 0.005 0.01 < 0.005 < 0.005 < 0.005 0.17 0.17 < 0.005 0.02 0.02 — 2.04 2.04 < 0.005 < 0.005 < 0.005 2.15 Annual — — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.09 0.74 0.89 < 0.005 0.03 — 0.03 0.03 — 0.03 — 209 209 0.01 < 0.005 — 210 Dust
From
Material
Movement
— — — — — 0.05 0.05 — < 0.005 < 0.005 — — — — — — —
Onsite
truck
< 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.03 0.03 < 0.005 < 0.005 < 0.005 — 0.34 0.34 < 0.005 < 0.005 < 0.005 0.36 Offsite — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.21 0.23 3.01 0.00 0.00 0.98 0.98 0.00 0.23 0.23 — 898 898 0.01 0.04 0.07 909 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 Hauling 0.01 0.73 0.32 < 0.005 0.01 0.17 0.17 0.01 0.05 0.05 — 603 603 0.04 0.10 0.03 633 OC Riverwalk Detailed Report, 2/4/2025
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Average
Daily
— — — — — — — — — — — — — — — — —
Worker 0.02 0.02 0.25 0.00 0.00 0.08 0.08 0.00 0.02 0.02 — 73.0 73.0 < 0.005 < 0.005 0.09 74.0 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 Hauling < 0.005 0.06 0.03 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 — 48.4 48.4 < 0.005 0.01 0.04 50.8 Annual — — — — — — — — — — — — — — — — —
Worker < 0.005 < 0.005 0.05 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 — 12.1 12.1 < 0.005 < 0.005 0.02 12.2 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 Hauling < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 — 8.01 8.01 < 0.005 < 0.005 0.01 8.41

3.11. Linear, Paving (2028) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Location 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-Road
Equipment

1.31 12.2 19.5 0.03 0.42 — 0.42 0.39 — 0.39 — 2,955 2,955 0.12 0.02 — 2,966 Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 25.4 25.4 < 0.005 < 0.005 0.04 26.8 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

1.31 12.2 19.5 0.03 0.42 — 0.42 0.39 — 0.39 — 2,955 2,955 0.12 0.02 — 2,966 Onsite
truck
< 0.005 0.07 0.05 < 0.005 < 0.005 2.23 2.23 < 0.005 0.22 0.22 — 25.5 25.5 < 0.005 < 0.005 < 0.005 26.9 Average
Daily
— — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.28 2.60 4.18 0.01 0.09 — 0.09 0.08 — 0.08 — 632 632 0.03 0.01 — 634 ------------------
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Onsite
truck
< 0.005 0.02 0.01 < 0.005 < 0.005 0.45 0.45 < 0.005 0.05 0.05 — 5.45 5.45 < 0.005 < 0.005 < 0.005 5.73 Annual — — — — — — — — — — — — — — — — —
Off-Road
Equipment

0.05 0.47 0.76 < 0.005 0.02 — 0.02 0.02 — 0.02 — 105 105 < 0.005 < 0.005 — 105 Onsite
truck
< 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.08 0.08 < 0.005 0.01 0.01 — 0.90 0.90 < 0.005 < 0.005 < 0.005 0.95 Offsite — — — — — — — — — — — — — — — — —
Daily,
Summer
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.13 0.12 2.22 0.00 0.00 0.62 0.62 0.00 0.15 0.15 — 597 597 0.01 < 0.005 1.72 600 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 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 Daily,
Winter
(Max)
— — — — — — — — — — — — — — — — —
Worker 0.13 0.14 1.90 0.00 0.00 0.62 0.62 0.00 0.15 0.15 — 568 568 0.01 0.02 0.04 575 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 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 Average
Daily
— — — — — — — — — — — — — — — — —
Worker 0.03 0.03 0.43 0.00 0.00 0.13 0.13 0.00 0.03 0.03 — 123 123 < 0.005 < 0.005 0.16 125 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 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 Annual — — — — — — — — — — — — — — — — —
Worker 0.01 0.01 0.08 0.00 0.00 0.02 0.02 0.00 0.01 0.01 — 20.4 20.4 < 0.005 < 0.005 0.03 20.7 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 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

4. Operations Emissions Details
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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) Vegetatio
n
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
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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4.10.3. 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 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 — — — — — — — — — — — — — — — — —
Avoided — — — — — — — — — — — — — — — — —
Subtotal — — — — — — — — — — — — — — — — —
------------------
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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 Linear, Grubbing & Land
Clearing
Linear, Grubbing & Land
Clearing
6/1/2026 8/12/2026 5.00 52.0 —
Linear, Grading &
Excavation
Linear, Grading &
Excavation
8/13/2026 7/6/2027 5.00 234 —
Linear, Drainage, Utilities,
& Sub-Grade
Linear, Drainage, Utilities,
& Sub-Grade
7/7/2027 2/10/2028 5.00 156 —
Linear, Paving Linear, Paving 2/11/2028 5/30/2028 5.00 78.0 —

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 Linear, Grubbing &
Land Clearing
Signal Boards Electric Average 7.00 8.00 6.00 0.82
Linear, Grubbing &
Land Clearing
Crawler Tractors Diesel Average 2.00 8.00 87.0 0.43
Linear, Grubbing &
Land Clearing
Excavators Diesel Average 3.00 8.00 36.0 0.38
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Linear, Grading & Excavators Diesel Average 7.00 8.00 36.0 0.38 Excavation
Linear, Grading &
Excavation
Crawler Tractors Diesel Average 3.00 8.00 87.0 0.43
Linear, Grading &
Excavation
Cranes Diesel Average 1.00 8.00 367 0.29
Linear, Grading &
Excavation
Graders Diesel Average 3.00 8.00 148 0.41
Linear, Grading &
Excavation
Rollers Diesel Average 5.00 8.00 36.0 0.38
Linear, Grading &
Excavation
Tractors/Loaders/Back
hoes
Diesel Average 4.00 8.00 84.0 0.37
Linear, Grading &
Excavation
Signal Boards Electric Average 7.00 8.00 6.00 0.82
Linear, Grading &
Excavation
Rubber Tired Loaders Diesel Average 4.00 8.00 150 0.36
Linear, Grading &
Excavation
Scrapers Diesel Average 6.00 8.00 423 0.48
Linear, Drainage,
Utilities, & Sub-Grade
Scrapers Diesel Average 6.00 8.00 423 0.48
Linear, Drainage,
Utilities, & Sub-Grade
Rough Terrain Forklifts Diesel Average 2.00 8.00 96.0 0.40 Linear, Drainage,
Utilities, & Sub-Grade
Signal Boards Electric Average 7.00 8.00 6.00 0.82
Linear, Drainage,
Utilities, & Sub-Grade
Tractors/Loaders/Back
hoes
Diesel Average 4.00 8.00 84.0 0.37
Linear, Drainage,
Utilities, & Sub-Grade
Graders Diesel Average 3.00 8.00 148 0.41
Linear, Drainage,
Utilities, & Sub-Grade
Plate Compactors Diesel Average 2.00 8.00 8.00 0.43
Linear, Drainage,
Utilities, & Sub-Grade
Pumps Diesel Average 2.00 8.00 11.0 0.74
Linear, Drainage,
Utilities, & Sub-Grade
Air Compressors Diesel Average 2.00 8.00 37.0 0.48
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Linear, Drainage, Generator Sets Diesel Average 2.00 8.00 14.0 0.74 Utilities, & Sub-Grade
Linear, Paving Rollers Diesel Average 4.00 8.00 36.0 0.38 Linear, Paving Paving Equipment Diesel Average 2.00 8.00 89.0 0.36 Linear, Paving Pavers Diesel Average 2.00 8.00 81.0 0.42 Linear, Paving Tractors/Loaders/Back
hoes
Diesel Average 4.00 8.00 84.0 0.37
Linear, Paving Signal Boards Electric Average 7.00 8.00 6.00 0.82

5.3. Construction Vehicles

5.3.1. Unmitigated
Phase Name Trip Type One-Way Trips per Day Miles per Trip Vehicle Mix Linear, Grubbing & Land Clearing — — — —
Linear, Grubbing & Land Clearing Worker 30.0 18.5 LDA,LDT1,LDT2 Linear, Grubbing & Land Clearing Vendor 0.00 10.2 HHDT,MHDT Linear, Grubbing & Land Clearing Hauling 27.9 20.0 HHDT Linear, Grubbing & Land Clearing Onsite truck 4.00 1.50 HHDT Linear, Grading & Excavation — — — —
Linear, Grading & Excavation Worker 100 18.5 LDA,LDT1,LDT2 Linear, Grading & Excavation Vendor 2.00 10.2 HHDT,MHDT Linear, Grading & Excavation Hauling 18.9 20.0 HHDT
Linear, Grading & Excavation Onsite truck 4.00 1.50 HHDT Linear, Drainage, Utilities, &
Sub-Grade
— — — —
Linear, Drainage, Utilities, &
Sub-Grade
Worker 75.0 18.5 LDA,LDT1,LDT2
Linear, Drainage, Utilities, &
Sub-Grade
Vendor 0.00 10.2 HHDT,MHDT
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Linear, Drainage, Utilities, & Hauling 9.19 20.0 HHDT
Sub-Grade
Linear, Drainage, Utilities, &
Sub-Grade
Onsite truck 4.00 1.50 HHDT
Linear, Paving — — — —
Linear, Paving Worker 47.5 18.5 LDA,LDT1,LDT2
Linear, Paving Vendor 0.00 10.2 HHDT,MHDT
Linear, Paving Hauling 0.00 20.0 HHDT
Linear, Paving Onsite truck 4.00 1.50 HHDT

5.4. Vehicles

5.4.1. Construction Vehicle Control Strategies
Control Strategies Applied PM10 Reduction PM2.5 Reduction Water unpaved roads twice daily 55% 55%
Limit vehicle speeds on unpaved roads to 25 mph 44% 44%

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)

5.6. Dust Mitigation

5.6.1. Construction Earthmoving Activities
Phase Name Material Imported (Cubic
Yards)
Material Exported (Cubic
Yards)
Acres Graded (acres) Material Demolished (sq. ft.) Acres Paved (acres) Linear, Grubbing & Land
Clearing

0.00 11,600 37.7 0.00 —
Linear, Grading & Excavation 17,700 17,700 37.7 0.00 —
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Linear, Drainage, Utilities, &
Sub-Grade
11,460 0.00 37.7 0.00 —

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
Bridge/Overpass Construction 0.68 100%
Road Construction 33.1 100%
User Defined Linear 0.59 100%
User Defined Linear 0.00 0%

5.8. Construction Electricity Consumption and Emissions Factors kWh per Year and Emission Factor (lb/MWh)
Year kWh per Year CO2 CH4 N2O
2026 411 1,040 0.09 0.01
2027 411 1,040 0.09 0.01
2028 411 1,040 0.09 0.01

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 OC Riverwalk Detailed Report, 2/4/2025
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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 10.1 annual days of extreme heat Extreme Precipitation 3.85 annual days with precipitation above 20 mm Sea Level Rise — meters of inundation depth
Wildfire 0.00 annual hectares burned
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.

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6.2. Initial Climate Risk Scores
Climate Hazard Exposure Score Sensitivity Score Adaptive Capacity Score Vulnerability Score Temperature and Extreme Heat 1 0 0 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 N/A N/A N/A N/A
Drought N/A N/A N/A N/A
Snowpack Reduction N/A N/A N/A N/A
Air Quality Degradation 0 0 0 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 1 1 1 2
Extreme Precipitation N/A N/A N/A N/A
Sea Level Rise 1 1 1 2
Wildfire 1 1 1 2
Flooding N/A N/A N/A N/A
Drought N/A N/A N/A N/A
Snowpack Reduction N/A N/A N/A N/A
Air Quality Degradation 1 1 1 2
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.

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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 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 51.9
AQ-PM 84.1
AQ-DPM 86.6
Drinking Water 57.1
Lead Risk Housing 17.1
Pesticides 3.69
Toxic Releases 92.8
Traffic 84.9
Effect Indicators —
CleanUp Sites 95.1
Groundwater 75.0
Haz Waste Facilities/Generators 97.9
Impaired Water Bodies 0.00
Solid Waste 22.1
Sensitive Population —
Asthma 38.8
Cardio-vascular 18.3
Low Birth Weights 21.6
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Socioeconomic Factor Indicators —
Education 52.9
Housing 57.4
Linguistic 65.6
Poverty 54.2
Unemployment 0.91

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 62.74862056
Employed 76.78686
Median HI 65.26369819
Education —
Bachelor's or higher 51.32811497
High school enrollment 100
Preschool enrollment 37.79032465
Transportation —
Auto Access 69.12613884
Active commuting 22.53304247
Social —
2-parent households 87.91222892
Voting 30.28358784
Neighborhood —
Alcohol availability 49.89092776
Park access 24.62466316
Retail density 91.18439625
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Supermarket access 18.51661748
Tree canopy 11.39484152
Housing —
Homeownership 25.08661619
Housing habitability 42.43551906
Low-inc homeowner severe housing cost burden 33.3504427 Low-inc renter severe housing cost burden 77.27447709
Uncrowded housing 45.59219813
Health Outcomes —
Insured adults 71.51289619
Arthritis 88.7
Asthma ER Admissions 56.9
High Blood Pressure 87.7
Cancer (excluding skin) 57.8
Asthma 72.9
Coronary Heart Disease 81.5
Chronic Obstructive Pulmonary Disease 79.3
Diagnosed Diabetes 83.3
Life Expectancy at Birth 68.9
Cognitively Disabled 26.7
Physically Disabled 45.1
Heart Attack ER Admissions 72.1
Mental Health Not Good 62.3
Chronic Kidney Disease 79.8
Obesity 78.0
Pedestrian Injuries 81.1
Physical Health Not Good 73.7
Stroke 84.7
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Health Risk Behaviors —
Binge Drinking 7.0
Current Smoker 56.8
No Leisure Time for Physical Activity 58.0
Climate Change Exposures —
Wildfire Risk 0.0
SLR Inundation Area 0.0
Children 29.7
Elderly 61.9
English Speaking 41.5
Foreign-born 61.2
Outdoor Workers 35.0
Climate Change Adaptive Capacity —
Impervious Surface Cover 12.0
Traffic Density 92.9
Traffic Access 70.4
Other Indices —
Hardship 28.3
Other Decision Support —
2016 Voting 50.4

7.3. Overall Health & Equity Scores
Metric Result for Project Census Tract
CalEnviroScreen 4.0 Score for Project Location (a) 53.0 Healthy Places Index Score for Project Location (b) 60.0 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 OC Riverwalk Detailed Report, 2/4/2025
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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
Construction: Paving No new paved area for impoundment structures Appendix D. Biological Resources Technical Report
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Biological Resources
Technical Report
OC River Walk Project
February 2025
Prepared for:

City of Anaheim
Community Services Department, Parks Division
200 S. Anaheim Boulevard, Suite 433
Anaheim, California 92805
Contact: Ana Straabe, Principal Project Planner
Prepared by:
2375 Northside Drive, Suite 125
San Diego, California 92108
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Biological Resources Technical Report i February 2025
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Table of Contents
Acronyms and Abbreviations ..................................................................................................v Executive Summary............................................................................................................ES-1 Section 1 Introduction...........................................................................................................1

1.1 Purpose of the Report ....................................................................................1 Section 2 Environmental Setting..........................................................................................3

2.1 Project Location .............................................................................................3

2.2 Project Description.........................................................................................3

2.3 Project Purpose..............................................................................................4

2.4 Land Use........................................................................................................4

2.5 Topography and Soils ....................................................................................5

2.6 Hydrology.......................................................................................................5

2.7 Climate...........................................................................................................6 Section 3 Regulatory Framework .........................................................................................9

3.1 Federal...........................................................................................................9

3.2 State ............................................................................................................10

3.3 Local ............................................................................................................12

3.3.1 County of Orange Central and Coastal Subregion Natural Communities Conservation Plan/Habitat Conservation Plan.............12

3.3.2 City of Anaheim General Plan...........................................................12

3.3.3 City of Orange General Plan.............................................................14 Section 4 Methods...............................................................................................................17

4.1 Literature Review .........................................................................................17

4.2 General Biological Survey ............................................................................17

4.2.1 Vegetation and Land Cover Type Mapping.......................................17

4.2.2 Plant and Wildlife Species Observations...........................................18

4.2.3 Aquatic Resources Delineation.........................................................18

4.3 Survey Limitations........................................................................................18 Section 5 Results.................................................................................................................21

5.1 Vegetation Communities and Land Cover Types..........................................21

5.1.1 Aquatic Communities........................................................................22

5.1.2 Scrub and Riparian Scrub Communities ...........................................23

5.1.3 Woodland and Forest Communities..................................................24

5.1.4 Disturbed/Developed Land Cover Types ..........................................24

5.2 Jurisdictional Aquatic Resources..................................................................25

5.3 Observed Species........................................................................................26

5.3.1 Plant Species ...................................................................................26

5.3.2 Wildlife Species ................................................................................26

5.4 Sensitive Species.........................................................................................27 Biological Resources Technical Report ii February 2025
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5.4.1 Critical Habitat ..................................................................................30

5.4.2 Sensitive Plant Species Observed....................................................30

5.4.3 Sensitive Plant Species Not Observed with a High Potential to Occur............................................................................................30

5.4.4 Sensitive Wildlife Species Observed.................................................31

5.4.5 Sensitive Wildlife Species Not Observed with a High Potential to Occur............................................................................................33

5.4.6 Nesting Birds ....................................................................................34

5.4.7 Roosting Bats ...................................................................................35

5.4.8 Wildlife Corridors and Habitat Linkages ............................................35 Section 6 Impact Analysis ..................................................................................................37

6.1 Significance Thresholds and Definition of Impacts .......................................37

6.1.1 Direct Impacts...................................................................................37

6.1.2 Indirect Impacts ................................................................................38

6.2 Threshold 1: Sensitive Plant and Wildlife Species ........................................38

6.2.1 Guidelines for Determination of Significance ....................................38

6.2.2 Impact Analysis ................................................................................38

6.2.3 Mitigation Measures..........................................................................42

6.2.4 Significance after Mitigation..............................................................49

6.3 Threshold 2: Sensitive Vegetation Communities ..........................................50

6.3.1 Guidelines for Determination of Significance ....................................50

6.3.2 Impact Analysis ................................................................................50

6.3.3 Mitigation Measures..........................................................................51

6.3.4 Significance after Mitigation..............................................................51

6.4 Threshold 3: Jurisdictional Aquatic Resources .............................................51

6.4.1 Guidelines for Determination of Significance ....................................51

6.4.2 Impact Analysis ................................................................................51

6.4.3 Mitigation Measures..........................................................................53

6.4.4 Significance after Mitigation..............................................................53

6.5 Threshold 4: Wildlife Corridors and Habitat Linkages ...................................53

6.5.1 Guidelines for Determination of Significance ....................................53

6.5.2 Impact Analysis ................................................................................53

6.5.3 Mitigation Measures..........................................................................54

6.5.4 Significance after Mitigation..............................................................55

6.6 Threshold 5: Local Policies or Ordinances ...................................................55

6.6.1 Guidelines for Determination of Significance ....................................55

6.6.2 Impact Analysis ................................................................................55

6.6.3 Mitigation Measures..........................................................................55

6.6.4 Significance after Mitigation..............................................................55

6.7 Threshold 6: Regional Conservation Planning..............................................55

6.7.1 Guidelines for Determination of Significance ....................................55

6.7.2 Impact Analysis ................................................................................56 Biological Resources Technical Report iii February 2025 OC River Walk Project

6.7.3 Mitigation Measures..........................................................................56

6.7.4 Significance after Mitigation..............................................................56

6.8 Cumulative Impacts......................................................................................56

6.8.1 Cumulative Threshold 1: Sensitive Plant and Wildlife Species..........56

6.8.2 Cumulative Threshold 2: Sensitive Vegetation Communities ............56

6.8.3 Cumulative Threshold 3: Jurisdictional Aquatic Resources...............57

6.8.4 Cumulative Threshold 4: Wildlife Corridors and Habitat Linkages.....57

6.8.5 Cumulative Threshold 5: Local Policies or Ordinances .....................57

6.8.6 Cumulative Threshold 6: Regional Conservation Planning ...............58 Section 7 References ..........................................................................................................59 Tables
Table 1. Existing Land Use Acreages .........................................................................................4 Table 2. City of Anaheim General Plan Green Element Consistency ........................................13 Table 3. City of Orange General Plan Natural Resources Element Consistency .......................14 Table 4. Vegetation Communities and Land Cover Types on the Project Site and in the Survey Buffer.................................................................................................................21 Table 5. Jurisdictional Aquatic Resources on the Project Site and in the Survey Buffer (Acres)................................................................................................................26 Table 6. Sensitive Plant and Wildlife Species with Potential to Occur in the Survey Area .........27 Appendices
Appendix A. Figures
Appendix B. Species Observed
Appendix C. Aquatic Resources Delineation Report
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Acronyms and Abbreviations
°F degrees Fahrenheit
amsl above mean sea level
BIOS Biogeographic Information and Observation System
BMP best management practice
Cal-IPC California Invasive Plant Council
CDFW California Department of Fish and Wildlife
CEQA California Environmental Quality Act
CESA California Endangered Species Act
CFGC California Fish and Game Code
City City of Anaheim
CNPS California Native Plant Society
CRPR California Rare Plant Rank
CWA Clean Water Act
FESA Federal Endangered Species Act
GIS geographic information system
Harris Harris & Associates
HCP Habitat Conservation Plan
MBTA Migratory Bird Treaty Act
MM Mitigation Measure
NCCP Natural Communities Conservation Plan
NHD National Hydrography Dataset
NPDES National Pollutant Discharge Elimination System
NRCS Natural Resources Conservation Service
NWI National Wetlands Inventory
OC River Walk Orange County River Walk
OCWD Orange County Water District
OHWM Ordinary High Water Mark
Porter−Cologne Porter−Cologne Water Quality Control Act PRC California Public Resource Code
Project Orange County River Walk Project
RWQCB Regional Water Quality Control Board
SAR1 Levee System (Upstream Reach) Santa Ana River 1 Levee System SR State Route
SWRCB State Water Resources Control Board
USACE U.S. Army Corps of Engineers
USC U.S. Code
USDA U.S. Department of Agriculture
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geological Survey
WL Watch List
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Biological Resources Technical Report ES-1 February 2025 OC River Walk Project
Executive Summary
Harris & Associates (Harris) has prepared this Biological Resources Technical Report in support of the Draft Environmental Impact Report for the proposed OC River Walk Project (project). The project site consists of approximately 33 acres of land and approximately 77.8 acres of aquatic areas for a total of 110.8 acres. The majority of the project site is composed of a concrete-lined portion of the Santa Ana River corridor, Collin’s Channel, and two Orange County Water District water detention basins (Burris Basin and Former Ball Road Basin). The remainder of the project site is urban and commercial land with small portions of open space vegetated with both native and nonnative plant species. The project site is outside the County of Orange Central & Coastal Subregion Natural Communities Conservation Plan/Habitat Conservation Plan area. The project aims to transform the Santa Ana River corridor into an iconic location and experience to be currently known as OC River Walk. The project would be generally designed around the following objectives:
• Activate the existing recreational areas, pedestrian foot traffic, and bikeways in the project vicinity.
• Implement sustainable projects that will benefit and promote the community’s health, recreation, economic, safety, entertainment, water supply, and natural resource needs. • Ensure future uses are integrated to ensure that the projects connect and complement existing or planned recreational, entertainment and transportation facilities, and implement projects identified in the Master Plan to transform the river to create a visually appealing asset.
• Provide outdoor venues for recreation and entertainment while improving the ecology of the river corridor.

The analysis of biological resources was carried out through a review of existing maps, literature, and resource databases, and data was collected during the field survey conducted by Harris biologists. A general biological reconnaissance survey and a formal aquatic resources delineation were conducted by Harris in May 2023 to map vegetation communities and land cover types, document observed plant and wildlife species, evaluate the potential for occurrence of sensitive plant and wildlife species, and identify and document aquatic resources on the project site and within a 100-foot survey buffer surrounding the project site (herein referred to as the survey area). No focused or protocol surveys were conducted during the 2023 survey.

Nine vegetation communities and land cover types were identified in the survey area. Native vegetation and aquatic communities in the survey area are fresh water, emergent wetland, nonvegetated channel, Diegan coastal sage scrub, mulefat scrub (disturbed), and southern willow scrub. The survey area also includes non-native woodland. Two land cover types, disturbed habitat and developed land, were also observed in the survey area.

Biological Resources Technical Report ES-2 February 2025 OC River Walk Project
The results of the 2023 aquatic resources delineation determined that a total of 84.54 acres of nonwetland waters occur in the survey area that are potentially under the jurisdiction of the following agencies: the U.S. Army Corps of Engineers, Regional Water Quality Control Board, and California Department of Fish and Wildlife.

No sensitive plant species were observed in the survey area, and based on the literature and database review, no sensitive plant species were determined to have a high potential to occur in the survey area.

Four sensitive wildlife species were observed in the survey area during the biological survey:

American white pelican (Pelecanus erythrorhynchos), double-crested cormorant (Phalacrocorax auritus), least Bell’s vireo (Vireo bellii pusillus), and yellow warbler (Setophaga petechial). Two sensitive wildlife species, American peregrine falcon (Falco peregrinus anatum) and western mastiff bat (Eumops perotis californicus), were determined to have a high potential to occur in the survey area but were not observed during the biological resource survey. The survey area was determined to have a high potential to support nesting birds, protected under California Fish and Game Code and Migratory Bird Treaty Act, as well as sensitive roosting bats.

The project is required to be in compliance with all federal, state, and local regulations applicable to biological resources, including jurisdictional aquatic resources, as a condition of approval. The project could result in potentially significant direct and indirect impacts to sensitive wildlife species, including sensitive nesting birds and roosting bats. The project could result in potential impacts to five sensitive vegetation communities, including aquatic resources regulated by the U.S.

Army Corps of Engineers, Regional Water Quality Control Board, and California Department of Fish and Wildlife. Mitigation would include the following measures: monitoring by a qualified biologist, adherence to required mitigation ratios for compensatory mitigation, revegetation of native habitats, and pre-construction sensitive bird surveys. All potentially significant impacts would be reduced to a less than significant level with implementation of mitigation measures.

Consistency with federal, state, and local regulations and the application of mitigation measures would ensure that the project is consistent with the City of Anaheim’s General Plan Green Element and the City of Orange Natural Resources Element, and would not result in cumulatively considerable impacts to biological resources.

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Section 1 Introduction
Harris & Associates (Harris) was contracted by the City of Anaheim (City), the lead agency, to conduct desktop literature reviews and reconnaissance-level biological survey in support of the Draft Environmental Impact Report to analyze the impacts of the Orange County River Walk (OC River Walk) Project (project) in the Cities of Anaheim and Orange, California.

1.1 Purpose of the Report
The purpose of this Biological Resources Technical Report is to document the biological resources present in the project site and 100-foot survey buffer (herein referred to as the survey area); identify potential impacts to special-status biological resources associated with implementation of the project; and document avoidance, minimization, and/or mitigation measures consistent with federal, state, and local rules and regulations. This report includes an introduction; a discussion of environmental setting and a project description; a summary of the applicable federal, state, and local regulations applicable to biological resources; methods for the literature review and survey conducted for the project, including survey limitations; results reflecting data from the survey conducted with a description and analysis of existing biological resources, including sensitive biological resources; an analysis of potential project impacts, including cumulative impacts, and mitigation required to reduce potential impacts from project implementation to below a level of significance; and references consulted during preparation of this Biological Resources Technical Report.

The term “biological resources” refers to plant species, wildlife species, vegetation communities, and aquatic resources in and adjacent to the project site. For the purposes of this report, sensitive biological resources are those defined as follows: (1) species designated as endangered, threatened, rare, protected, sensitive, or species of special concern according to the U.S. Fish and Wildlife Service (USFWS), California Department of Fish and Wildlife (CDFW), California Native Plant Society (CNPS), or applicable regional plans, policies, or regulations needs due to limited distribution, limited numbers, or significant population declines associated with natural or human-made causes; (2) species and habitat types recognized by local and regional resource agencies as special status; (3) habitats or vegetation communities that are unique, are of relatively limited distribution, or are of particular value to wildlife; (4) wildlife corridors and habitat linkages; or (5) biological resources that may or may not be considered special status but are regulated under local, state, and/or federal laws.

This report discusses potential impacts, avoidance areas, and mitigation measures (MMs) applicable to biological resources associated with implementation of the project in accordance with the federal Endangered Species Act (FESA); California Endangered Species Act (CESA) (CFGC, Section 2050 et seq.); California Environmental Quality Act (CEQA); Clean Water Act (CWA); Porter−Cologne Water Quality Control Act (Porter−Cologne); Migratory Bird Treaty Act (MBTA); and Sections 1600, 1602, 3511, and 4700 of the California Fish and Game Code (CFGC).

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Section 2 Environmental Setting
The following is a description of the existing conditions in the survey area.

2.1 Project Location
The project site is located along the Santa Ana River corridor, generally extending from Orangewood Avenue north to Ball Road and the existing Anaheim Coves at Burris Basin, encompassing approximately a 2-mile stretch and approximately 111 acres. The project site is adjacent to Angel Stadium, Anaheim Regional Transportation Intermodal Center, the Honda Center, and the Arena Corporate Center (ACC) buildings on the west side in the City of Anaheim (Appendix A, Figures; Figure 1, Regional Location, and Figure 2, Local Vicinity). On the east side, it is near the Sandra Hutchens Regional Law Enforcement Training Center (a facility that includes a combat shooting range), the Orange County Public Works offices, the Stadium Promenade shopping mall, the Extended Stay America – Orange, and the Kinder Morgan Orange Terminal in the City of Orange. The project site is located within the Cities of Anaheim and Orange, with many different landowners and jurisdictional bodies.

The majority of the project site includes the concrete-lined Santa Ana River corridor surrounded by urban development, including commercial, industrial, and residential uses, within the Cities of Anaheim and Orange (Figure 2). The Santa Ana River is within the Orange County Water District’s (OCWD) jurisdiction north of the Union Pacific Railroad (UPRR) and within the Orange County Flood Control District’s (OCFCD) jurisdiction south of the UPRR. Within the boundaries of the project site, five overcrossings and/or bridges span the Santa Ana River: Ball Road Bridge, UPRR overcrossing, Katella Avenue Bridge, Metrolink/Los Angeles-San Diego-San Luis Obispo Rail Corridor (LOSSAN Corridor) railroad overcrossing, and Orangewood Avenue Bridge.

Additionally, State Route (SR-) 57 crosses the Santa Ana River. The northern portion of the project site includes the Orange County Water District (OCWD) pump house, associated water detention basins, and the eastern portion of the Islands Golf Center. The project site’s northern boundary connects to the existing Anaheim Coves at Burris Basin.

2.2 Project Description
The project consists of consists of various multi-purpose improvements to transform the Santa Ana River corridor and portions of the existing Santa Ana River Trail, along with related off-site improvements necessary for its implementation. The main components of the Conceptual Master Plan involve creating two water impoundments by installing three inflatable rubber dams, modifying the riverbanks, constructing two pedestrian/bike bridges, providing new trails, improving existing trails, creating new and protection of existing access ramps, constructing two new undercrossings on the west bank at the Union Pacific Railroad and the Metrolink railroad, providing enhanced community amenities (e.g., terraced seating, nature play areas, parklets, Biological Resources Technical Report 4 February 2025
OC River Walk Project
plazas, gathering areas for large-scale events, festivals, and other activities, water access, kayak launch, etc.), and other improvements. These improvements would require the implementation of 19 project elements, which have been categorized into four groups: Group A – Impoundments, Storm Drain Diversions, and Embankments; Group B – New Pedestrian/Bike Bridges; Group C – New Trails and Trail Improvements; and Group D – Enhanced Community Recreation Amenities, as shown Table ES-1, Conceptual Master Plan Elements.

2.3 Project Purpose
The following objectives have been established for the project and will aid decision makers in their review of the project and associated environmental impacts:

1. Adopt a Master Plan for OC River Walk Project to further enhance and accentuate existing recreational areas, facilitate pedestrian and bicycle access, and promote the use of the river corridor open space area for the community benefit.

2. Implement projects identified in the Master Plan that will create visually appealing outdoor public amenities that will benefit and promote environmental and community health, recreation, safety, entertainment, wayfinding, art, education, cultural awareness, beauty, connectivity, water supply, economic, and natural resource needs.

3. Provide seamless and cohesive improvements across jurisdictions on the project site to benefit the public and the area’s aesthetics.

4. Implement projects to transform and improve the river and riverbed’s groundwater recharge potential and improve the river corridor’s ecology (flora and fauna).

5. Maintain and enhance flood protection capacity and resiliency.

6. Enhance connectivity and community access by leveraging the project site's location near ARTIC, major entertainment venues, and adjacent mixed-use developments

2.4 Land Use
The existing land uses and associated acreages on the project site are described in Table 1, Existing Land Use Acreages, and are shown on Figure 2.

Table 1. Existing Land Use Acreages
Land Use Acres
Aquatic Area (Including Rivers/Creeks/Open Water) 77.81 Urban/Commercial Land (Including Roads) 28.00
Vegetated Land 5.07
Total 110.88
Notes: Acreages rounded to one-hundredth of an acre
The primary land use on the project site is aquatic area, including the Santa Ana River corridor, Collin’s Channel, and the two OCWD water detention basins (Burris Basin and Former Ball Road Biological Resources Technical Report 5 February 2025
OC River Walk Project
Basin) in the northwestern portion of the project site. Aquatic land uses comprise approximately

77.81 acres on the project site. Approximately 28 acres of urban/commercial land account for most of the remaining land uses throughout the project site, with a small area, approximately 5.07 acres, of vegetated land primarily in the northwestern portion of the project site. The project site is surrounded by urban and commercial land, including roads, as well as the upstream and downstream extents of the Santa Ana River to the north and south. The northwestern portion of the project site is surrounded by aquatic areas within The Islands Golf Center and OCWD owned and operated water distribution plant.

2.5 Topography and Soils
The project site is in a relatively flat urban setting, with the greatest elevation decreases occurring in the Santa Ana River corridor and the Burris and Former Ball Road Basins (Figure 2 and Figure 3, USGS Topographic Map). The survey area is depicted on the U.S. Geological Survey (USGS)

7.5-minute Anaheim quadrangle in Township 4 South, Range 10 West, Sections 13, 24, and 25 and the 7.5-minute Orange quadrangle in Township 4 South, Range 9 West, Sections 18 and 19 (Figure 3). The on-site elevation ranges from approximately 133 to 190 feet above mean sea level.

The topographic lines on Figure 3 represent the elevations that occur on the project site.

The project site is underlain by three soil types: Metz loamy sand (zero to 2 percent slopes), Pits (zero to 5 percent slopes), and Riverwash (Figure 4, Soils). The northeastern corner of the survey area that cannot be characterized by soil type is water. Metz loamy sand occurs along the eastern edge of the project site and consists of somewhat excessively drained soils that formed in alluvial material from mixed, but dominantly sedimentary rocks, typically found in alluvial fans and floodplains. Pits constitutes a small portion in the northwestern corner of the project site and consists of poorly drained soils that formed in fine-textured alluvium weathered from igneous rocks that are found on flood plains and in basins. Riverwash represents the majority of the survey area and consists of very recent depositions of gravel, sand, and silt alluvium along major streams and their tributaries (USDA 2019). The Riverwash and Pits soil types that occur on the project site are classified as hydric (wetland) soils and have the potential to contain hydric inclusions (USDA 2019).

2.6 Hydrology
The project site is in the Santa Ana River Watershed (Hydrologic Unit 18070203) (USGS 2025).

The Santa Ana River Watershed is the largest in Southern California and encompasses 2,840 square miles within portions of Riverside and Orange Counties, and a small part of eastern Los Angeles County (USGS 2025). Santa Ana River Watershed supports a population of over 6 million people across these counties. The total length of the Santa Ana River and the streams that drain into it is approximately 700 miles, starting from its northernmost reaches at the crest of the San Bernardino Mountains out to the coast near Huntington Beach. This network of waterways includes features that are both natural and channelized in concrete. The Santa Ana River is defined by the U.S. Army Biological Resources Technical Report 6 February 2025
OC River Walk Project
Corps of Engineers (USACE) as a traditional navigable water (USACE 2025). Portions of the Santa Ana River are on the CWA Section 303(d) List for impaired waters, however, the reach in the survey area is not listed as impaired (SWRCB 2025).

The portion of the Santa Ana River within the survey area also contains the USACE constructed Santa Ana River 1 Levee System (SAR1 Levee System) (Upstream Reach) (USACE 2015). The SAR1 Levee System (Upstream Reach) was federally authorized and subsequently constructed by the USACE, Los Angeles District. Construction of the SAR1 Levee System (Upstream Reach) was completed in 1999 and is now entirely operated and maintained by Orange County Flood Control District, which is administered by Orange County Public Works staff (USACE 2015).

The National Wetlands Inventory (NWI) results identify several mapped aquatic features in the survey area (Figure 5, National Wetlands Inventory Results) (USFWS 2021). The Santa Ana River within the boundary of the project site is identified as a lake but is more accurately characterized as having lacustrine system1, as is also Burris Basin in the northwestern portion of the survey area (NWI 2025). The Former Ball Road Basin, west of the Santa Ana River and south of the Burris Basin, is identified on the NWI results as both freshwater emergent wetland and freshwater pond. One riverine feature (Collin’s Channel) is identified connecting to the east side of the Santa Ana River in the central portion of the survey area. No other aquatic features are identified in the survey area by the NWI results.

Based on a review of the USGS National Hydrography Dataset (NHD), the survey area contains several mapped aquatic resources, including those that have hydrologic connections to the Santa Ana River (USGS 2025). The Santa Ana River is identified as a stream/river with an artificial path, likely because of the concrete channelization of the river and construction of the SAR1 Levee System (Upstream Reach). Both Burris Basin and Former Ball Road Basin are identified as reservoirs with intermittent connections to each other and the Santa Ana River. Collin’s Channel is identified as a canal/ditch that is connected to the Santa Ana River from the east. No other aquatic features are identified in the survey area by the USGS NHD results. The aquatic resources that occur in the survey area are discussed in Section 5.2, Jurisdictional Aquatic Resources.

2.7 Climate
On a regional level, Orange County has a Mediterranean climate, which is characterized by wet winters and dry summers. This is largely because of a semi-permanent high-pressure zone that sits over the Pacific Ocean during much of the year and forms a fog belt (marine layer). Generalized climate in the region is regarded as dry, subhumid mesothermal, with warm dry summers and cold moist winters, which pushes the growing season to the wet months of the year (late winter to early 1 The lacustrine system includes wetlands and deepwater habitats with all of the following characteristics: (1) situated in a topographic depression or a dammed river channel; (2) lacking trees, shrubs, persistent emergents, and emergent mosses or lichens with 30 percent or greater areal coverage; and (3) total area of at least 8 hectares (ha) (20 acres) (NMI 2025).

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spring). Annual vegetation often goes dormant (senescent) during the later summer months until initial rainfall starts in the fall. The rainy season typically lasts from late October through April.

Average temperatures for this area range from 52 degrees Fahrenheit (°F) to 72°F. Typically, August is the warmest and driest month, February is the wettest month, and December is the coldest month of the year. Average precipitation in the rainy season is approximately 2.2 inches per month (October to March). The average annual precipitation for the project site between 2003 and 2023 was approximately 13.2 inches. In 2022, the total rainfall was 6.35 inches, approximately 1.7 inches less than 2021 (NRCS 2025). As of May 2023, when the biological resources survey was conducted, total precipitation in the area was 19.4 inches, approximately 18 inches more than May 2022.

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Section 3 Regulatory Framework
This section summarizes federal, state, regional, and local regulations, plans, policies, and programs that provide protection and management of sensitive biological resources that are applicable to the project. The federal government administers nonmarine plant- and wildliferelated issues through the USFWS, while waters of the United States issues are administered by the USACE. California law relating to wetland, water-related, and wildlife issues is administered by the CDFW. Under CEQA, the CEQA lead agency (in this case, the City of Anaheim) assesses impacts associated with a proposed project or program using significance criteria determined by the CEQA lead agency pursuant to the CEQA Guidelines. Biological resources-related laws and regulations that apply include FESA, MBTA, CWA, CEQA, CESA, and CFGC.

3.1 Federal
CWA, Section 404 (33 CFR 328.3[a]). These provisions regulate the discharge of dredged or fill material in waters of the United States (U.S), including wetlands. Activities that discharge dredge or fill material into waters of the U.S. can be authorized by the USACE.

On August 29, 2023, the U.S. Environmental Protection Agency (USEPA) and the USACE issued a final rule to amend the final “Revised Definition of Waters of the U.S.” The 2023 final rule became effective on September 8, 2023. Under the 2023 final rule:
(a) Waters of the U.S. are defined as:

1. Waters which are:
i. Currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide;
ii. The territorial seas; or
iii. Interstate waters;

2. Impoundments of waters otherwise defined as waters of the United States under this definition, other than impoundments of waters identified under (a)(5) of this section;

3. Tributaries of waters identified in (a)(1) or (2) of this section that are relatively permanent, standing or continuously flowing bodies of water;

4. Wetlands adjacent to the following waters:
i. Waters identified in (a)(1) of this section; or
ii. Relatively permanent, standing or continuously flowing bodies of water identified in (a)(2) or (a)(3) of this section and with a continuous surface connection to those waters; iii. Intrastate lakes and ponds not identified in (a)(1) through (4) of this section that are relatively permanent, standing or continuously flowing bodies of water with a continuous surface connection to the waters identified in (a)(1) or (a)(3) of this section.

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FESA, Sections 7 and 9 (16 USC 1531 et seq.; 50 CFR Part 402). FESA prohibits the “take” (i.e., harm, harass, or kill individuals, or destroy associated habitat) of species federally listed as threatened or endangered. Take incidental to otherwise lawful activities can be authorized by the USFWS through a permit under Sections 4(d), 7, or 10(a).

MBTA (16 USC 703–712; 50 CFR 10). The federal MBTA prohibits the direct or indirect take of migratory birds and their active nests unless permitted.

Section 408 of the Rivers and Harbors Act. Section 408 program allows another party, such as a local government, company, or individual, to alter a USACE Civil Works project. The Section 408 program verifies that changes to authorized USACE Civil Works projects will not be injurious to the public interest and will not impair the usefulness of the project.

Sections 9 and 10 of the Rivers and Harbors Act. Section 9 of the Rivers and Harbors Act prohibits the construction of any bridge, dam, dike, or causeway over or in navigable waterways of the United States without Congressional approval. Administration of Section 9 has been delegated to the U.S. Coast Guard. Consultation with the U.S. Coast Guard may be necessary to determine if a Section 9 permit would be required under the Rivers and Harbors Act.

Section 10 of the Rivers and Harbors Act requires that permits be obtained from the USACE in navigable waters of the United States for all structures such as riprap and activities such as dredging.

USACE grants or denies Section 10 permits based on the effects on navigation. Most projects covered under this act are also covered under Section 404 of the CWA.

3.2 State
Birds of Prey Protection Provision (CFGC, Section 3503.5). This provision prohibits the taking of birds of prey (order Falconiformes and Strigiformes) including their nests and eggs.

California Endangered Species Act (CFGC, Section 2050 et seq.). Section 2050 of the CFGC prohibits any activities that would jeopardize or take a species designated as threatened or endangered by the state.

California Fish and Game Code, Section 1602. Section 1602 regulates water resources in the State of California. Activities that divert or obstruct the natural flow of or change or use material from the bed, channel, or bank of any river stream or lake may be authorized by the CDFW. CDFW jurisdiction includes intermittent and perennial watercourses and extends to the top of the bank of a stream or lake if unvegetated or to the limit of the adjacent riparian vegetation, located contiguous to the watercourse, if the stream or lake is vegetated.

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California Fish and Game Code, Section 3503. Section 3503 of the CFGC prohibits the take, possession, or needless destruction of the nests or eggs of any birds, except as otherwise provided by the code or any regulation made pursuant thereto.

CEQA, as amended (PRC, Section 21000 et seq.). The goal of CEQA is to assist California public agencies in identifying potential significant negative environmental impacts caused by their actions and avoiding or mitigating those impacts when feasible.

California Fully Protected Wildlife Species Provision (CFGC, Sections 3511, 4700, 5050, and 5515).

These provisions prohibit the taking of fully protected birds, mammals, amphibians, and fish.

California Native Plant Protection Act of 1977 (CFGC, Sections 1900–1913). These provisions preserve, protect, and enhance endangered or rare native plants of the state.

Regional Water Quality Control Board. The Regional Water Quality Control Board (RWQCB) regulates impacts to water quality under Section 401 of the CWA. A project must comply with Section 401 of the CWA before the USACE can issue a Section 404 Permit. The RWQCB will issue a Section 401 Water Quality Certification or Waiver of Certification, depending on the extent of impacts to waters of the United States. The RWQCB also regulates impact to waters of the state (usually limited to “isolated” waters or swales that may not fall under USACE jurisdiction) under the Porter−Cologne.

Streambed Alteration Agreement (CFGC, Section 1600). The CFGC requires any person who proposes a project that will substantially divert or obstruct the natural flow or substantially change the bed, channel, or bank of any river, stream, or lake, or their tributaries, or use materials from a streambed, to submit a notification for a Streambed Alteration Agreement to the CDFW.

Natural Community Conservation Planning Act, as amended (CFGC, Sections 2800–2835). The primary objective of the Natural Community Conservation Planning program is to conserve natural communities at the ecosystem level while accommodating compatible land use. The program seeks to anticipate and prevent the controversies and gridlock caused by species’ listing by focusing on the long-term suitability of wildlife and plant communities and including key interests in the process.

Porter−Cologne. Regulated by the RWQCB for impacts to waters of the state. Although water quality issues related to impacts to waterways are normally addressed during 401 Water Quality Certification, should a water of the State of California be determined by the USACE not to have CWA jurisdiction, Porter−Cologne would be addressed under a Construction General Permit, State General Waste Discharge Order, or Waste Discharge Requirements, depending on the level of impact and the properties of the waterway.

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3.3 Local

3.3.1 County of Orange Central and Coastal Subregion Natural Communities Conservation Plan/Habitat Conservation Plan
The County of Orange Central & Coastal Subregion Natural Communities Conservation Plan/Habitat Conservation Plan (NCCP/HCP) was approved in 1996. It provides a planning framework for development projects within the program’s planning area in order to avoid, minimize, and compensate for impacts to wildlife (County of Orange 1996). The purpose of the NCCP/HCP is to sustain and restore species and their habitat identified by CDFW as necessary to maintain the continued viability of biological communities impacted by growth and development.

The City of Anaheim is enrolled in NCCP/HCP. According to the City of Anaheim General Plan Green Element, a portion of the City, generally south of State Route (SR) 91 Freeway and east of SR-55 Freeway, falls within the NCCP/HCP boundary in the City of Anaheim 2004. The City of Orange is enrolled in the NCCP/HCP. A portion of the City near SR-241, SR-261, and Santiago Canyon Road falls within the NCCP/HCP boundary in the City of Orange (ARCGIS 2025). The project site is not within the boundaries of the NCCP/HCP. Therefore, the project is not subject to the requirements of the NCCP/HCP.

3.3.2 City of Anaheim General Plan
The project is in the City of Anaheim and, therefore, subject to the goals and policies of the City of Anaheim General Plan (City of Anaheim 2004). The City of Anaheim General Plan was adopted in May 2004 and was most recently amended in August 2022. It represents the community’s view of its future and is referred to as the blueprint for growth and development in the City of Anaheim.

The City of Anaheim General Plan is considered “comprehensive,” because it addresses a multitude of land use-related issues. It is also considered “long-term,” because it is designed to provide policy guidance for the next 20 years and beyond. The City of Anaheim General Plan contains 10 elements that provide a comprehensive “blueprint” for the City of Anaheim’s growth over the next 20-plus years. As shown on the City of Anaheim General Plan Land Use Map (Figure LU-4), the project site is in an area designated as Open Space, Water, and Mixed-Use Urban Core.

The City of Anaheim General Plan element applicable to biological resources on the project site includes the Green Element. Table 2, City of Anaheim General Plan Green Element Consistency, documents the project’s consistency with the applicable Green Element goals and policies.

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Table 2. City of Anaheim General Plan Green Element Consistency Goal/Policy Proposed Project
Green Element
Goal 4.1. Maximize the recreational and scenic potential of existing reservoirs, basins and waterways.

Policy 1. Support the County of Orange to continue in their efforts to upgrade and maintain the Santa Ana River Trail.

Consistent: The project is designed to implement
sustainable projects that will benefit and promote
the community’s health, recreation, economics,
safety, entertainment, water supply, and natural
resource needs. The goal of the project is to
transform the Santa Ana River to create a visually
appealing asset and provide outdoor venues for
recreation and entertainment while improving the
ecology of the river corridor.

Goal 4.1.

Policy 2. Work with the County of Orange and the Orange County Water District to maintain and improve the recreational and scenic resources of the Anaheim Lakes and Five Coves areas and other appropriate water resource areas, including regarding basins and reservoirs.

Consistent: Refer to response to Goal 4.1, Policy
1, regarding the project’s design to maintain and
improve the recreational and scenic resources of
the Santa Ana River and surrounding water
basins.

Goal 7.1. Reduce urban run-off from new and existing development.

Policy 1. Ensure compliance with the Federal Clean Water Act requirements for National Pollutant Discharge Elimination System (NPDES) permits, including developing and requiring the development of Water Quality Management Plans for all new development and significant redevelopment in the City.

Consistent: The project would include
implementation of water quality protection
measures, such as water quality detention/swale
areas; and implementation of BMPs. The project
would be in compliance with the NPDES
regulations to ensure the control of polluted
runoff, sedimentation, and erosion during
construction. Future activities consistent with the
project would implement these measures and
policies and be consistent with this goal.

Goal 7.1.

Policy 2. Continue to implement an urban runoff reduction program consistent with regional and federal requirements, which includes requiring and encouraging the following:
• Increase permeable areas and install filtration controls (including grass lined swales and gravel beds) and divert flow to these permeable areas to allow more percolation of runoff into the ground;
• Use natural drainage, detention ponds or infiltration pits to collect runoff; and,
• Prevent rainfall from entering material and waste storage areas and pollution-laden surfaces.

Consistent: Refer to response to Goal 7.1 Policy 2
regarding urban runoff reduction and
management requirements.

Goal 7.1.

Policy 4. Require new development and significant redevelopment to utilize site preparation, grading and best management practices that provide erosion and sediment control to prevent construction-related contaminants from leaving the site and polluting waterways.

Consistent: Refer to response to Goal 7.1 Policy 2
regarding water quality protection measures.

Goal 7.1.

Policy 5. Coordinate with appropriate Federal, State, and local resource agencies on development projects and construction activities affecting waterways and drainages.

Consistent: Refer to response to Goal 7.1 Policy 2
regarding water quality protection measures. The
project would be compliance with all federal,
state, and local regulations applicable to the
protection of aquatic resources and would ensure
no net loss of existing jurisdictional aquatic
resources as a result of the project.

Notes: BMP = best management practices; NPDES = National Pollutant Discharge Elimination System Biological Resources Technical Report 14 February 2025
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3.3.3 City of Orange General Plan
The project is in the City of Orange and therefore subject to the goals and policies of the City General Plan (City of Orange 2010). The City of Orange General Plan was adopted in March 2010 and was most recently amended in January 2025. It represents a long-term vision for growth and change and is referred to as the blueprint to help influence physical growth and change in the City of Orange while protecting citizen’s quality of life. The City of Orange General Plan addresses a broad range of quality-of-life issues and services and contains 10 elements that provide a comprehensive “blueprint” for the City of Orange’s growth through the year 2030. As shown on the City of Orange General Plan Land Use Policy Map (Figure LU-5), the project site is in an area designated as Open Space.

The Natural Resources Element of the City of Orange General Plan is the most relevant to biological resources on the project site. Table 3, City of Orange General Plan Natural Resources Element Consistency, outlines the applicable goals and policies, as well as the project's consistency with them.

Table 3. City of Orange General Plan Natural Resources Element Consistency Goal/Policy Proposed Project
Goal 1.0: Provide recreational use, scenic enjoyment, and the protection of natural resources and features in open space areas.

Policy 1.1: Conserve open space through various public-private funding mechanisms and management strategies including, but not limited to, conservation easements.

Policy 1.2: Actively seek out new public open space opportunities through land recycling.

Policy 1.3: Promote development of additional open spaces and access points adjacent to waterways and planned trails.

Consistent: The project is designed to
implement sustainable projects that will
benefit and promote the community’s health,
recreation, economics, safety, entertainment,
water supply, and natural resource needs.

The goal of the project is to transform the
Santa Ana River to create a visually
appealing asset and provide outdoor venues
for recreation and entertainment while
improving the ecology of the river corridor.

Goal 2.0: Protect air, water, and energy resources from pollution and overuse.

Policy 2.3: Reduce the amount of water used for landscaping through the use of native and drought-tolerant plants, proper soil preparation, and efficient irrigation systems as parks and other City facilities are built or renovated.

Policy 2.4: Encourage the production, distribution, and use of recycled and reclaimed water for landscaping projects, while maintaining urban runoff water quality objectives.

Policy 2.6: Encourage sustainable building and site designs for new construction and renovation projects.

Policy 2.8: Encourage development that incorporates pedestrian- and transitoriented design and landscape elements.

Policy 2.11: Protect the ecological integrity and overall health of Orange’s watersheds.

Policy 2.12: Cooperate with water supply agencies to protect the quantity and quality of local groundwater supplies.

Policy 2.13: Control surface runoff water discharges into the stormwater conveyance system to comply with the City’s National Pollutant Discharge Elimination System (NPDES) Municipal Permit and other regional permits issued by the Santa Ana Regional Water Quality Control Board.

Consistent: Refer to response to Goal 1,
Policies 1.1 through 1.3, regarding the
project’s design to implement sustainable
projects that will benefit and promote the
community’s health. The project includes trail
improvements and two pedestrian/bike
bridges that would support alternative
transportation modes and bicycle- and
pedestrian-friendly neighborhoods to reduce
emissions related to vehicular travel. The
project also includes two river impoundments
for groundwater recharge areas and improve
the river corridor’s ecology and enhance
flood protection capacity.

The project includes implementation of water
quality protection measures, such as water
quality detention/swale areas; and
implementation of BMPs. The project would
be in compliance with the NPDES
regulations to ensure the control of polluted
runoff, sedimentation, and erosion during
construction.

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Table 3. City of Orange General Plan Natural Resources Element Consistency Goal/Policy Proposed Project
Policy 2.14: Reduce pollutant runoff from new development by requiring use of the most low development impact practices and effective Best Management Practices (BMPs) currently available.

Policy 2.15: Minimize the amount of impervious surfaces and associated urban runoff pollutants in new development and significant redevelopment throughout the community.

Policy 2.16: Protect in-stream habitat and natural stream and channel features.

Goal 4.0: Conserve and protect wildlife habitat, plant and animal species of concern, and general biodiversity.

Policy 4.1: Preserve and protect native and habitat-supporting plant resources throughout the City.

Policy 4.3: Reduce the impact of urban development on important ecological and biological resources.

Policy 4.4: Repair or improve ecological and biological conditions in the urban and natural environments when reviewing proposals for site development and redevelopment, as well as public improvements.

Policy 4.5: Protect the Santiago Creek and Santa Ana River corridors from premature urbanization to ensure the continued availability of important sand and gravel, flood control, water recharge, biological, and open space resources.

Consistent: The project is designed to
implement sustainable projects that will
benefit and promote the community’s health,
recreation, economics, safety, entertainment,
water supply, and natural resource needs.

The goal of the project is to transform the
Santa Ana River to create a visually
appealing asset and provide outdoor venues
for recreation and entertainment while
improving the ecology of the river corridor.

While the project would result in temporary
direct loss of wildlife habitat during
construction, project would include aquatic
and upland habitat restoration to the Santa
Ana River corridor, and result in a permanent
increase in potentially suitable nesting and
foraging habitat for wildlife species.

Goal 5.0: Provide recreational facilities and programs that adequately serve the needs of residents.

Policy 5.4: Develop new public parks and open space resources by establishing incentives to use creative techniques available to property owners and developers that support public-private open space partnerships.

Policy 5.5: Explore and pursue new approaches to new park development and to providing a balanced mix of amenities and facilities.

Consistent: The project is designed to
implement sustainable projects that will
benefit and promote the community’s health,
recreation, economics, safety, entertainment,
water supply, and natural resource needs.

The goal of the project is to transform the
Santa Ana River to create a visually
appealing asset and provide outdoor venues
for recreation and entertainment while
improving the ecology of the river corridor.

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Section 4 Methods
Before the biological resourcessurvey was performed, sensitive biological resources with potential to occur in the survey area were identified through a review of existing maps, literature, and sensitive species occurrence databases.

4.1 Literature Review
The following databases and publications were reviewed before the biological resource survey was conducted:
• Calflora Database (Calflora 2025)
• CNPS Inventory of Rare and Endangered Plants (CNPS 2025) • CDFW Biogeographic Information and Observation System (BIOS) (CDFW 2025a) • CDFW California Natural Diversity Database (CDFW 2025b) • U.S. Department of Agriculture Soil Survey (USDA 2025) • USFWS National Wetlands Inventory Wetlands Mapper (USFWS 2025a) • USFWS Information for Planning and Consultation (USFWS 2025b)

4.2 General Biological Survey
Harris biologists conducted a general biological reconnaissance survey and a formal aquatic resources delineation survey on May 16, 2023. During the survey, the biologists mapped vegetation communities, documented observed plant and wildlife species, and evaluated the potential for occurrence of sensitive plant and wildlife species by walking slowly along the meandering transects throughout the survey area. No in-water surveys were conducted by Harris during the May 16, 2023, survey efforts. The aquatic resources delineation was conducted using the routine on-site determination method described in the USACE Wetlands Delineation Manual (USACE 1987) and the Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Arid West Region (USACE 2008). No focused or protocol wildlife surveys or rare plant surveys were conducted during this survey effort.

A discussion of the 2023 survey activities conducted in the survey area is provided in the following subsections.

4.2.1 Vegetation and Land Cover Type Mapping
Vegetation communities and land cover types observed on the project site and within its surrounding 100-foot survey buffer (herein referred to as the survey area) were mapped by Harris biologists using Geographic Information Systems (GIS) aerial maps connected to an iSXBlue II Global Positioning System receiver for maximum accuracy. The vegetation communities and land cover types were documented by walking along meandering transects through the survey area (where accessible).

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The vegetation community and land cover type mapping is in accordance with the Preliminary Descriptions of the Terrestrial Natural Communities of California (Holland 1986).

4.2.2 Plant and Wildlife Species Observations
Wildlife identifications were made in the field directly through visual observation or indirectly through call, burrow, track, or scat detection. Latin and common names of wildlife follow Crother (2012) for reptiles and amphibians, American Ornithological Society (2019) for birds, Wilson and Reeder (2005) for mammals, and Moyle (2002) for fish.

Plant and wildlife species observed during the survey were recorded in field notebooks, and sensitive species locations were recorded in a Geographic Information Systems-enabled ArcGIS Collector application. Complete lists of observed plant and wildlife species are provided in Appendix B, Species Observed.

In addition to species detected during the survey, the survey area was assessed for the potential of sensitive plant and wildlife species to occur on site, the results of which are presented in Section 5.4, Sensitive Species. Determinations were made through assessment of habitat preferences, knowledge of local and regional distributions, and review of pertinent literature and local recorded occurrences.

Plants that could not be identified in the field by the surveyors were collected and subsequently identified using the Jepson Manual, Vascular Plants of California, Second Edition (Baldwin et al. 2012). Plant nomenclature follows Baldwin et al. (2012). Non-native invasive plant species were identified using the California Invasive Plant Council’s California Invasive Plant Inventory rating criteria (Cal-IPC 2025).

4.2.3 Aquatic Resources Delineation
The formal aquatic resources delineation was conducted to identify and document aquatic resources in the survey area. An Arid West Region Ordinary High Water Mark (OHWM) datasheet and a USACE three-parameter wetland determination datasheet for the Arid West Region (wetland determination datasheet) were completed at each sampling point for each unique aquatic resource feature (USACE 1987, 2008). Each aquatic resources sampling point was collected to investigate the presence and extent of potential wetland and non-wetland waters in the survey area. The full results and discussion of the aquatic resources delineation are documented in Appendix C, Aquatic Resources Delineation Report, and summarized in Section 5.2 of this report.

4.3 Survey Limitations
Plants and wildlife were identified by direct observation, vocalizations, or other observance, including tracks, scat, and other signs. Therefore, lists of observed species are not necessarily comprehensive because species can be outside their blooming periods and/or in senescence, Biological Resources Technical Report 19 February 2025
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nocturnal, secretive, or within the region (project area) seasonally or during migration only and, therefore, may not have been observed.

Some areas were not directly surveyed due to a lack of habitat (i.e., developed areas), and other areas were not accessible on foot (i.e., open water). These areas were either not directly reviewed because of lack of habitat or could only be visually scanned rather than walked. The Burris and Former Ball Road Basins are on private property and not accessible on foot. In these areas, binoculars were used to collect aquatic resources delineation data to complete the wetland determination datasheets to the extent feasible.

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Section 5 Results
The results presented below reflect data from the survey conducted in the survey area.

5.1 Vegetation Communities and Land Cover Types
The survey area is in the South Coast subregion of the California Floristic Province (Jepson Online 2025). The vegetation classifications in this report conform to the Preliminary Descriptions of the Terrestrial Natural Communities of California (Holland 1986) and the California Natural Community List (CDFW 2025c).

A total of nine vegetation communities and land cover types were identified in the survey area:
fresh water, emergent wetland, non-vegetated channel, Diegan coastal sage scrub, mulefat scrub (disturbed), southern willow scrub, non-native woodland, disturbed habitat, and developed land.

Table 4, Vegetation Communities and Land Cover Types on the Project Site and in the Survey Buffer, shows the vegetation communities occurring on both the project site and survey buffer.

Figure 6, Vegetation Communities and Land Cover Types, presents the vegetation community and land cover type boundaries on the Project site and survey buffer.

Table 4. Vegetation Communities and Land Cover Types on the Project Site and in the Survey Buffer
Vegetation Community and Land
Cover Type Project Site (acres)1 Survey Buffer (acres)1 Survey Area (acres)1 Aquatic
Freshwater2 3.48 3.15 6.63
Freshwater emergent wetland2 0.00 0.97 0.97
Non-vegetated channel2 74.33 1.95 76.28
Subtotal 77.81 6.07 83.88
Scrub and Riparian Scrub
Diegan coastal sage scrub2 0.21 0.95 1.16
Mulefat scrub (disturbed)2 0.38 0.00 0.38
Southern willow scrub2 0.66 0.97 1.63
Subtotal 1.25 1.92 3.17
Woodland and Forest
Non-native woodland 0.22 0.00 0.22
Disturbed/Developed
Disturbed habitat 3.60 2.75 6.35
Developed land 28.00 40.27 68.27
Subtotal 31.60 43.02 74.62
Total 110.88 51.01 161.89
Sources: CDFW 2025c; Holland 1986.

Notes:
1 Acreages rounded up to one-hundredth.
2 Considered a sensitive vegetation community by CDFW.

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5.1.1 Aquatic Communities

5.1.1.1 Fresh Water
Fresh water includes year-round bodies of fresh water in the form of lakes, streams, ponds, or rivers. Fresh water includes those portions of water bodies that are usually covered by water and contain less than 10 percent vegetated cover (Holland 1986).

A total of approximately 6.63 acres of fresh water was documented, with 3.48 acres occurring within the project site and the remaining 3.15 acres in the survey buffer (Figure 6). The fresh water in the survey area occurs within both Burris Basin and Former Ball Road Basin, as well as The Islands Golf Center and the OCWD owned and operated water distribution plant in the northwestern portion of the survey area. Both Burris Basin and Former Ball Road Basin have direct surface water connectivity to the Santa Ana River, directly east of the basins.

5.1.1.2 Freshwater Emergent Wetland
Freshwater emergent wetlands are dominated by low-growing perennial wetland species. These can be found in channels, seeps and springs, floodplains, margins of lakes and rivers, and various basins such as pools and ponds, palustrine lakes, montane meadows, and dune swales.

Characteristic species include sedges (Carex sp.), spikerushes (Eleocharis sp.), rushes (Juncus sp.), docks and sorrels (Rumex sp.), and giant bur-reed (Sparganium eurycarpum), and many others (Holland 1986).

A total of approximately 0.97 acre of freshwater emergent wetland was documented within Former Ball Road Basin in the western edge of the survey buffer, outside the project site (Figure 6). The emergent wetland within Former Ball Road Basin appears to receive water from Burris Basin through a large concrete box culvert under Ball Road from the northwest. Saturated soils and surface water were observed in the emergent wetland during the May 2023 survey, and dominant plant species included curly dock (Rumex crispus), tall flatsedge (Cyperus eragrostis), Goodding’s willow (Salix gooddingii), mulefat (Baccharis salicifolia), and arundo (Arundo donax).

5.1.1.3 Non-Vegetated Channel
Non-vegetated channel consists of predominantly sandy, gravelly, or rocky channels lacking or with reduced vegetation. Variable water lines inhibit the growth of vegetation, although some weedy species of grasses may grow along the outer edges of the channel. Vegetation may exist here but is usually less than 10 percent of the total cover (Holland 1986).

Non-vegetated channel comprises the majority of the survey area. A total of approximately 76.28 acres of non-vegetated channel was documented, with 74.33 acres occurring within the project site and the remaining 1.95 acres in the survey buffer (Figure 6). The Santa Ana River and Collin’s Channel are both defined as non-vegetated channels. The extent of the Santa Ana River that runs Biological Resources Technical Report 23 February 2025
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northeast to southwest through the majority of the survey area is a fully concrete- and riprap-lined channel and does not support any vegetation. Collin’s Channel is a riprap- and concrete-lined channel that enters the eastern edge of the survey area and connects to the eastern side of the Santa Ana River. Sparse grasses and weeds were observed growing through the rock riprap in Collin’s Channel, however, no substantial vegetation community was observed in the channel.

5.1.2 Scrub and Riparian Scrub Communities

5.1.2.1 Diegan Coastal Sage Scrub
Diegan coastal sage scrub is composed of a variety of soft, low, aromatic shrubs, characteristically dominated by drought-deciduous species, such as California sagebrush (Artemisia californica), California buckwheat (Eriogonum fasciculatum), and sages (Salvia spp.), with scattered evergreen shrubs, including lemonade berry (Rhus integrifolia) and laurel sumac (Malosma laurina) (Holland 1986).

A total of approximately 1.16 acres of Diegan coastal sage scrub was documented, with 0.21 acre occurring on the project site and 0.95 acre in the survey buffer (Figure 6). Diegan coastal sage scrub was observed in the northwest corner of the survey area, bordering the Burris Basin, The Islands Golf Center, and the OCWD facilities. The Diegan coastal sage scrub in the survey area appears to be part of restoration efforts and shows evidence of purposefully planted (installed) vegetation. Dominant species in the Diegan coastal sage scrub include California sagebrush, California buckwheat, Cleveland sage (Salvia clevelandii), and mulefat.

5.1.2.2 Mule Fat Scrub (Disturbed)
Mulefat scrub is defined as depauperate, tall, herbaceous riparian scrub strongly dominated by mulefat. This early seral community is maintained by frequent flooding. Absent this, most stands would succeed to cottonwood- or sycamore-dominated riparian forests or woodlands. Mulefat scrub is often found along intermittent stream channels or large rivers with fairly coarse substrate and moderate depth to the water table. Characteristic species include mulefat, valley sedge (Carex barbarae), narrowleaf willow (Salix exigua), sandbar willow (S. hindsiana), arroyo willow (S. lasiolepis), and stinging nettle (Urtica holosericea) (Holland 1986).

Approximately 0.38 acre of mulefat scrub (disturbed) occurs on the project site, along the southwest shoreline of Burris Basin in the northwestern portion of the survey area (Figure 6).

No mulefat scrub was documented in the survey buffer. This habitat is relatively sparse, with patchy coverage of mulefat and has encroachment of black mustard (Brassica nigra) from nearby disturbed areas.

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5.1.2.3 Southern Willow Scrub
Southern willow scrub consists of dense, broad-leaved, winter-deciduous stands of trees dominated by shrubby willows (Salix sp.) in association with mulefat. This vegetation community typically occurs on loose, sandy, or fine gravelly alluvium deposited near stream channels during flood flows (Holland 1986).

A total of approximately 1.63 acres of southern willow scrub was documented, with 0.66 acre occurring in the northwestern portion of the project site and 0.97 acre in the western edge of the survey buffer (Figure 6). The 0.66 acre of southern willow scrub on the project site is within and along the western shore of Burris Basin. This area is dominated by Goodding’s willow, with mulefat and a small stand of bulrush (Typha sp.) in the understory. The 0.97 acre of southern willow scrub along the western edge of the survey buffer within Former Ball Road Basin is densely vegetated with Goodding’s willow with mulefat and black mustard (Brassica nigra) in the understory and outer edges.

5.1.3 Woodland and Forest Communities

5.1.3.1 Non-Native Woodland
Non-native woodland consists of exotic trees, usually intentionally planted, which are not maintained or artificially irrigated. Characteristic species in non-native woodland include eucalyptus (Eucalyptus sp.), tamarisk (Tamarix sp.), pines (Pinus sp.), or other non-native species.

Approximately 0.22 acre of non-native woodland occurs on the project site, in a narrow stand between The Islands Golf Center putting green and Burris Basin in the northwestern portion of the survey area (Figure 6). This area is dominated by arundo and tamarisk, with a small number of young Goodding’s willows in the northern edge bordering the southern willow scrub to the northwest.

5.1.4 Disturbed/Developed Land Cover Types

5.1.4.1 Disturbed Habitat
Disturbed habitat is a land cover type characterized by a predominance of non-native species, often introduced and established through human action. Disturbed habitat has often been physically disturbed by human activity and is no longer recognizable as a native or naturalized vegetation association but continues to retain a soil substrate. Typically, vegetation, if present, is nearly exclusively composed of non-native plant species such as ornamentals or ruderal exotic species (i.e., weeds).

A total of approximately 6.35 acres of disturbed habitat was documented, with 3.60 acres occurring on the project site and 2.75 acres in the survey area (Figure 6). Disturbed habitat was documented bordering the western, southern, and southeastern edges of Burris Basin and the northern and eastern edges of Former Ball Road Basin in the northern portion of the survey area, as well as Biological Resources Technical Report 25 February 2025
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along the northeastern edge of the Santa Ana River. Alteration of these areas from apparent mechanical disturbance was observed. These areas are dominated by black mustard, star thistle (Centaurea calcitrapa), and fountain grass (Pennisetum sp.), with patches of bare dirt throughout.

5.1.4.2 Developed Land
Developed land refers to areas that have been constructed upon or disturbed so severely that native vegetation is no longer supported. Developed land includes areas with permanent or semipermanent structures, pavement or hardscape, landscaped areas, and areas with a large amount of debris or other materials. Examples of these areas may include graded landscapes or areas, graded firebreaks, graded construction pads, construction staging areas, or areas that are repeatedly used in ways that prevent revegetation (e.g., parking lots, trails that have persisted for years).

A total of approximately 68.27 acres of developed land was documented, with 28 acres occurring on the project site and 40.27 acres in the survey area. The developed land in the survey area is the second most prevalent land cover type in the survey area, after non-vegetated channel. In the survey area, developed land includes roadways, parking lots, concrete sidewalks and bike paths, commercial and industrial buildings, The Islands Golf Center putting green, and areas of ornamental landscaping and decorative hardscape.

5.2 Jurisdictional Aquatic Resources
The results of the 2023 aquatic resources delineation determined that a total of 84.54 acres of nonwetland waters occur in the survey area that are potentially under the jurisdiction of the USACE, RWQCB, and CDFW, pursuant to Sections 404 and 401 of the CWA and Section 1602 of the CFGC. In addition, the reach of the Santa Ana River in the survey area contains the SAR1 Levee System (Upstream Reach) and therefore is potentially under the jurisdiction of the USACE pursuant to the Rivers and Harbors Act, Section 408.

Of the total 84.54 acres of aquatic resources documented in the survey area, 78.47 acres occur on the project site. These include aquatic and riparian vegetation communities (i.e., fresh water, nonvegetated channel, freshwater emergent wetland, and southern willow scrub) that occur in the survey area, which may fall under the regulatory jurisdiction of the USFWS, RWQCB, or CDFW (Figure 6). The regulatory agencies categorize aquatic resources into two types of ‘waters’:
wetland waters (i.e., delineated areas that contain hydrophytic plants, hydric soils, and wetland hydrology) and non-wetland waters (i.e., delineated areas that do not meet the criteria for wetlands, as previously defined). In the survey area, freshwater emergent wetland is considered a wetland water, while fresh water and non-vegetated channel are considered non-wetland waters.

Potentially jurisdictional aquatic resources mapped in the survey area are shown on Figure 7, Aquatic Resources. Table 5, Jurisdictional Aquatic Resources on the Project Site and in the Survey Buffer Biological Resources Technical Report 26 February 2025
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(Acres), provides a summary of these aquatic resources potentially under the jurisdiction of the USACE, RWQCB, and CDFW.

Table 5. Jurisdictional Aquatic Resources on the Project Site and in the Survey Buffer (Acres)
Feature Project Site (acres)
Survey Buffer
(acres) Jurisdiction
Santa Ana River 74.33 1.63 USACE1/RWQCB/CDFW
Collin’s Channel <0.01 0.32 USACE/RWQCB/CDFW
Burris Basin 3.48 3.15 USACE/RWQCB/CDFW
Burris Basin Southern Willow
Scrub

0.66 0.97 USACE/RWQCB/CDFW
Former Ball Road Basin
(Including Freshwater
Emergent Wetland)

0.00 0.97 USACE/RWQCB/CDFW
Total2 78.47 7.04 —
Notes: CDFW = California Department of Fish and Wildlife; RWQCB = Regional Water Quality Control Board; USACE = U.S. Army Corps of Engineers
1 Potentially subject to both the CWA Section 404 and Rivers and Harbors Act, Section 408. 2 Total rounded to one-hundredth of an acre.

A detailed discussion of the aquatic resources delineation results is included in Appendix C.

5.3 Observed Species

5.3.1 Plant Species
Appendix B lists the vascular plant species observed in the survey area during the biological resources survey. A total of 34 plant taxa were observed on the project site, 19 (56 percent) of which were native and 15 (44 percent) of which were non-native. No sensitive plant species were observed in the survey area. However, no focused rare plant surveys were conducted. The sensitive plant species evaluated for potential to occur in the survey area are described in Section 5.4.

5.3.2 Wildlife Species
Appendix B lists the wildlife species detected in the survey area during the biological resources survey. A total of 48 wildlife species, including five invertebrates, three fish, one amphibian, one reptile, 36 birds, and two mammals, were observed in the survey area during the biological resources survey. Of the 48 wildlife species observed in the survey area, four species, American white pelican (Pelecanus erythrorhynchos), double-crested cormorant (Phalacrocorax auritus), least Bell’s vireo (Vireo bellii pusillus), and yellow warbler (Setophaga petechia), are designated as sensitive. The sensitive species observed and those evaluated for potential to occur in the survey area are described in Section 5.4.

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5.4 Sensitive Species
Sensitive species are those recognized by federal, state, or local agencies as being potentially vulnerable to impacts because of rarity, local or regional reductions in population numbers, isolation/restricted genetic flow, or other factors. Special-status plants include those listed as threatened or endangered, proposed for listing, or candidates for listing by the USFWS and CDFW; those considered sensitive by the CDFW; those species included in the California Rare Plant Rank (CRPR) inventory maintained by the CNPS. Sensitive wildlife species include those listed as threatened or endangered, proposed for listing, or candidates for listing by the USFWS and CDFW; those considered sensitive by the CDFW; California Watch List (WL).

No focused sensitive plant or protocol sensitive wildlife surveys were conducted within the survey area during the 2023 survey.

As described in Section 4.1, Literature Review, distributions of historical sensitive species observations within 1 mile of the survey area were reviewed in preparation of this report. For the purposes of this biological resources assessment, those species that are known to occur or have some potential to occur within 1 mile of the survey area are addressed in this section. The list of potentially occurring sensitive plant and wildlife species is provided in Table 6, Sensitive Plant and Wildlife Species with Potential to Occur in the Survey Area, along with an assessment of their potential for occurrence in the survey area.

Table 6. Sensitive Plant and Wildlife Species with Potential to Occur in the Survey Area Scientific Name
Common
Name
Status
Federal/State/CRPR Habitat Potential to Occur
Plants
Abronia villosa var.
aurita
Chaparral
sand-verbena
None/None/1B.1 Occurs in sandy soils
in coastal sage scrub,
chaparral, and desert
dune habitats at
elevations between
245 and 5,250 feet
above mean sea level
(amsl). Blooms
January to
September.

Not Expected. The survey area is out of
elevation range for this species. Diegan
coastal sage scrub is present only in
northwestern portion; however, it is
likely a planted restoration area. A
historical location (from 1924) in the
Santa Ana River exists, however, this
occurrence is likely extirpated (Figure 8,
Sensitive Species with Potential to
Occur) (CDFW 2025b; Calflora 2025).

Eriastrum densifolium
ssp. sanctorum
Santa Ana
River
woollystar
FE/SE/1B.1 Occurs in sandy or
gravelly soils in
chaparral and coastal
sage scrub at
elevations between
300 and 2,000 feet
amsl. Blooms April
through September.

Not Expected. The survey area is out of
elevation range for this species. Diegan
coastal sage scrub is present only in
northwestern portion; however, it is
likely a planted restoration area. A
historical location exists; however, this
occurrence is documented within the
Orange County Quadrangle, and the
exact location is not known (CDFW
2025b; CNPS 2025).

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Table 6. Sensitive Plant and Wildlife Species with Potential to Occur in the Survey Area Scientific Name
Common
Name
Status
Federal/State/CRPR Habitat Potential to Occur
Wildlife
Fish
Oncorhynchus
mykiss irideus
(Southern California
Distinct Population
Segment)
Southern
California
steelhead
FE/SSC/None Occurs in cool, well
oxygenated
freshwater streams,
primarily in the upper
watersheds of most
rivers year-round.

Not Expected. The Santa Ana River,
the only potentially suitable habitat, is
completely concrete lined, with
concrete spillways making fish
passage unlikely. Water levels are too
low for fish passage, and mechanical
disturbance is currently preventing
higher potential for likelihood. A
historical location within 1 mile of the
survey area exists, however, the point
is not specific but mapped to the
quadrangle and therefore could be
further away than 1 mile (Figure 8)
(CDFW 2025b).

Reptiles
Phrynosoma blainvillii Blainville’s
horned lizard
None/SSC/None Occurs in open areas
of sandy soil and low
vegetation in foothills,
valleys, and semi-arid
mountains in
grasslands coniferous
forests, woodlands,
and chaparral. Also
found in lowlands
within sandy washes
with scattered shrubs
and long dirt roads.

Not Expected. No suitable habitat is
present in the survey area. A historical
location within 1 mile of the survey area
exists but is not known in the survey
area (Figure 8) (CDFW 2025b).

Birds
Falco peregrinus
anatum
American
Peregrine
falcon
None/FP, BCC/None Occurs in open
landscapes with cliffs
(or skyscrapers) for
nest sites, as well as
along rivers and
coastlines or in cities.

High Foraging. Not Expected Nesting.

High potential exists for the species to
be observed foraging in the survey
area, however, no suitable nesting
habitat is present. A historical location
within 1 mile of the survey area exists
but is not known in the survey area
(Figure 8) (CDFW 2025b).

Laterallus
jamaicensis ssp.
coturniculus
California black
rail
FP/ST/None Occurs in tidal salt
marshes or grassy
marshes with dense
strands of grasses,
rushes, and sedges
for nesting.

Low Foraging. Not Expected Nesting.

Suitable foraging habitat is limited to the
small wetland areas in the Burris Basin
and Former Ball Road basin. No
suitable nesting habitat is present in the
survey area. A historical location (from
1986) in the Santa Ana River exists,
however, this occurrence is likely
extirpated (Figure 8) (CDFW 2025b;
Calflora 2025).

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Table 6. Sensitive Plant and Wildlife Species with Potential to Occur in the Survey Area Scientific Name
Common
Name
Status
Federal/State/CRPR Habitat Potential to Occur
Pelecanus
erythrorhynchos
American
white pelican
BCC/SSC/None Occurs in coastal
bays, inlets,
estuaries, and
sloughs and inland
freshwater lakes.

Nests on isolated
islands in
freshwater lakes or
ephemeral islands
in shallow wetlands.

Breeding range in
California is limited
to the northeastern
corner of the state.

Present. High Foraging, Not
Expected Nesting. Observed in the
Santa Ana River in the northern
portion of the survey area (Figure 9,
Sensitive Species Observed).

Suitable foraging habitat occurs in
the Santa Ana River and in the
Burris and Former Ball Road
Basins. No suitable nesting habitat
occurs in the survey area.

Phalacrocorax
auritus (nesting
colony)
Doublecrested
cormorant
None/WL/None Occurs in salt and
freshwater habitats.

Nests on the ground,
on cliff edges, trees,
shrubs, and in
artificial surfaces on
and near Channel
Islands and coast
lines and lakes
elsewhere in the U.S.

Present. High Foraging, Moderate
Nesting. Observed during 2023
survey foraging in the Santa Ana
River and sunning on sediment piles
in the river channel in the northern
survey area (Figure 9). Suitable
foraging habitat occurs in the Santa
Ana River and Burris Basin.

Suitable nesting habitat is present,
but lower likelihood to nest due to
high levels of human activity and
frequent disturbance.

Setophaga
petechial
Yellow
warbler
None/SSC/None Nests in welldeveloped riparian
woodlands and
montane scrub.

Present. High Foraging, Moderate
Nesting. Observed in the southern
willow scrub in Former Ball Road
Basin (Figure 9). No nests were
observed directly. Suitable
southern willow scrub is limited to
Burris Basin and Former Ball Road
Basin in the survey area, which
provide suitable foraging and
moderate quality, limited nesting
habitat. No historical locations for
this species occur in the survey
area.

Sternula
antillarum browni
California least
tern
FE, FP/SE/None Nests on open sandy
dunes and flats
lacking vegetation in
colonies along
California coastlines,
in lagoons, bays, and
estuaries.

Low Foraging. Not Expected Nesting.

Low potential exists for the species to
be observed foraging in the Santa Ana
River in the survey area because of the
far distance to nesting habitat. Not
expected for nesting within the survey
area, and no established colony has
been documented in the survey area.

Historical location within 1 mile of the
survey area exists but are not known in
the survey area (Figure 8) (CDFW
2025b).

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Table 6. Sensitive Plant and Wildlife Species with Potential to Occur in the Survey Area Scientific Name
Common
Name
Status
Federal/State/CRPR Habitat Potential to Occur
Vireo belli pusillus Least Bell’s
vireo
FE/SE/None Occurs in riparian
scrub and riparian
forest; and is a
summer resident in
Southern California
below 2,000 feet.

Present. High Foraging, Moderate
Nesting. At least one individual was
observed in the southern willow
scrub in Former Ball Road Basin
(Figure 9). No nests were observed
directly. Suitable southern willow
scrub is limited to Burris Basin and
Former Ball Road Basin in the
survey area, which provides
suitable foraging and moderate
quality nesting habitat. No historical
locations for this species occur in
the survey area.

Mammals
Eumops perotis
californicus
Western
mastiff bat
None/SSC/None Occurs in open, semiarid woodlands,
coastal scrub,
grasslands, palm
oases, chaparral,
desert scrub, and
urban habitats with
abundant roosting
locations
Low Roosting; High Foraging. An
abundance of overpasses, bridges,
and buildings provide crevices suitable
for temporary roosting during foraging.

Foraging habitat is present above the
open water in the Santa Ana River and
Burris Basin. A historical location
within 1 mile of the survey area exists,
but none is known in the survey area
(Figure 8) (CDFW 2025b).

Notes: BCC = Bird of Conservation Concern; FC = federal candidate; FP = federally protected; FE = federally endangered; FT = federally threatened; SE = state endangered; None = No status indicated for species; SE = state endangered; SSC = state species of special concern; WL = state watch list
CNPS CRPR Rare Plant Ranking
1B = rare, threatened, or endangered in California and elsewhere; 2B = rare, threatened, or endangered in California but more common elsewhere; 3 = a watch list of species about which more information is needed; 4 = a watch list of species of limited distribution
Threat Ranks: .1 = seriously threatened; .2 = moderately threatened Bold text: Species observed within the survey area.

5.4.1 Critical Habitat
The potential presence of critical habitat on the project area was also analyzed. No critical habitat for sensitive plant or wildlife species occurs in or within 1 mile of the survey area (CDFW 2025a, 2025b; USFWS 2025b).

5.4.2 Sensitive Plant Species Observed
No sensitive plant species were observed in the survey area during the 2023 survey.

5.4.3 Sensitive Plant Species Not Observed with a High Potential to Occur Based on the literature and database review, no sensitive plant species were determined to have a high potential to occur in the survey area.

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5.4.4 Sensitive Wildlife Species Observed
Four sensitive wildlife species, American white pelican (Pelecanus erythrorhynchos), doublecrested cormorant (Phalacrocorax auritus), least Bell’s vireo (Vireo bellii pusillus), and yellow warbler (Setophaga petechial), were observed in the survey area during the 2023 biological survey.

These sensitive wildlife species observed in the survey area are shown on Figure 9 and described in the following subsections.

5.4.4.1 American White Pelican (Pelecanus erythrorhynchos), BCC, SSC American white pelican is a USFWS Bird of Conservation Concern and a CDFW Species of Special Concern. American white pelican is a huge waterbird with very broad wings, a thick body, short legs, a long neck, and a massive bill that gives the head a unique, long shape. This species occurs in coastal bays, inlets, estuaries, and sloughs and in inland freshwater lakes. American white pelicans nest on isolated islands in freshwater lakes or ephemeral islands in shallow wetlands and forage for fish in shallow water on inland marshes, along lake or river edges, and in wetlands. This species’ breeding range in California has been reduced to the northeastern corner of the state (primarily Modoc, Siskiyou, and Lassen Counties), where they breed with regularity at Lower Klamath and Clear Lake National Wildlife Refuges. Threats to this species include diseases, severe weather, and loss of breeding and foraging habitats due to disturbance and water level changes.

An American white pelican was observed foraging in the Santa Ana River in the northern portion of the survey area during the 2023 biological survey (Figure 9). Suitable foraging habitat occurs in the Santa Ana River and Burris Basin in the northwestern portion of the survey area. No suitable nesting habitat occurs in the survey area, and no known nesting sites have been documented in or surrounding the survey area (Shuford and Gardali 2008).

5.4.4.2 Double-Crested Cormorant (Phalacrocorax auritus), WL Double-crested cormorant, a CDFW Watch List species, is a large waterbird with a small head, a long, kinked neck, and a thin, strongly hooked bill. Adults are brown-black with a small patch of yellow-orange skin on the face. Double-crested cormorants inhabit coasts and banks of inland lakes, and fresh, salt, and estuarine waters. This species resides along the entire coast of California and nests in colonies on the ground, on rocks or reefs with no vegetation, or atop both live and dead trees and occasionally human-made structures. Double-crested cormorants perch beside open water on unvegetated surfaces and require an elevated perch or open length of water for take-off.

This species eats primarily fish captured by swimming underwater, with just a few insects, crustaceans, or amphibians supplementing their diet. Threats to this species include loss of nesting habitat, and pollution, particularly discarded fishing gear and oil spills.

Double-crested cormorants were observed foraging in the Santa Ana River and perching on the sediment piles in the center of the river channel in the northern portion of the survey area during Biological Resources Technical Report 32 February 2025
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biological surveys (Figure 9). Suitable foraging habitat occurs in the Santa Ana River and Burris Basin in the northwestern portion of the survey area. No suitable nesting habitat occurs in the survey area.

5.4.4.3 Least Bell’s Vireo (Vireo bellii pusillus), FE, SE Least Bell’s vireo, a federally endangered and state endangered species, is a small songbird with a dull ashy-grey head, darker wings and tail, and a predominately buffy white underside. Least Bell’s vireo has narrow, white eye-rings and faint wingbars. This species is restricted to riparian woodland and is most frequent in areas that combine an understory of dense young willows or mulefat with a canopy of tall willows. Least Bell’s vireo occurs in riparian habitat in California and Baja California, Mexico, foraging for insects and spiders among dense shrubs and trees along rivers and streams. Historically, least Bell’s vireo was a common summer visitor to riparian habitat throughout much of California. Currently, this subspecies is found only in riparian woodlands in Southern California, with most breeding pairs in San Diego, Santa Barbara, and Riverside counties − with some in Los Angeles and Ventura Counties. Least Bell's vireo arrives in breeding grounds in late March and early April and returns to its wintering ground in September. This species is threatened by urbanization, agriculture, wildfires, firewood cutting, livestock grazing, flood control projects, and reservoir construction.

Least Bell’s vireo was observed calling in the survey buffer, outside the project site, in the southern willow scrub in Former Ball Road Basin during the 2023 survey (Figure 9). The suitable nesting and foraging habitat for least Bell’s vireo in the survey area is limited to the small stands of southern willow scrub in Burris Basin and Former Ball Road Basin. There is potential for the species to move between the two stands of southern willow scrub over Ball Road and through the concrete box culvert that runs under the road connecting the two basins. No least Bell’s vireo nests were observed during the survey; however, no protocol surveys were conducted.

5.4.4.4 Yellow Warbler (Setophaga petechial), SSC
Yellow warbler, a CDFW Species of Special Concern, is a bright yellow, small songbird with a medium-length tail and a rounded head. Males are bright yellow with streaking on their breasts and females are lighter yellow. The species nests in thickets along streams, both disturbed and well-developed riparian woodlands, and montane scrub. Yellow warblers feed primarily on insects and spiders. Nests are cups made out of grasses, bark strips, hairs, and feathers and placed in a deciduous sapling or shrub, 2 to 16 feet above the ground. Threats to this species include habitat loss and nest parasitism, particularly by brown-headed cowbirds (Molothrus ater).

Yellow warbler was observed in the survey buffer, outside the project site, in the southern willow scrub in Former Ball Road Basin during the 2023 survey (Figure 9). The suitable nesting and foraging habitat for yellow warbler in the survey area is limited to the small stands of southern willow scrub in Burris Basin and Former Ball Road Basin. The potential for this species to nest in the survey area is low because the available southern willow scrub does not have a well-developed Biological Resources Technical Report 33 February 2025
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canopy and is disturbed from apparent OCWD maintenance and the presence of unhoused encampments. Similar to least Bell’s vireo, there is potential for the species to move between the two stands of southern willow scrub in the basins. No nests were observed during the survey; however, no focused surveys were conducted.

5.4.5 Sensitive Wildlife Species Not Observed with a High Potential to Occur Based on the literature and database review, six sensitive wildlife species were considered for their potential to occur in the survey area but were not observed during the biological resources surveys (Table 6). Two sensitive wildlife species, including American peregrine falcon (Falco peregrinus anatum) and western mastiff bat (Eumops perotis californicus), were determined to have a high potential to occur in the survey area but were not observed during the biological resource survey.

These sensitive wildlife species with high potential to occur are described in the following subsections.

5.4.5.1 American Peregrine Falcon (Falco peregrinus anatum), FDL, BCC/SDL American peregrine falcon is a federally delisted, USFWS Bird of Conservation Concern, and state delisted species. American peregrine falcon is a large falcon with long, pointed wings and a long tail, and adults are blue-gray above with barred underparts and dark head. This species inhabits riparian woodland, forest, inland wetlands, and open landscapes with cliffs or other high humanmade structures such as skyscrapers and bridges, for nest sites, as well as along rivers and coastlines or in cities. This subspecies migrates throughout California, and breeds along the coast of Southern and Central California, inland north coastal mountains, Klamath Mountains, Cascade Range, Sierra Nevada, and Channel Islands. American peregrine falcons eat a variety of birds and bats and are known to occasionally steal fish and rodents captured by other raptors. Threats to this species include loss of nesting and foraging habitat and poisoning from rodenticides.

Suitable foraging habitat and prey is present in the Santa Ana River and in both Burris Basin and Former Ball Road Basin in the survey area. However, no cliffs or high skyscrapers and bridges suitable for nesting are present in the survey area. One historical location for American peregrine falcon exists within 1 mile of the survey area, however, this species is not known to occur in the survey area (Figure 8) (CDFW 2025b).

5.4.5.2 Western Mastiff Bat (Eumops perotis californicus), SSC Western mastiff bat, a CDFW Species of Special Concern, is North America’s largest bat, with a long tail, dark grey fur, long narrow wings, and large ears that are oriented forward and joined at the midline above the forehead. Western mastiff bat typically roosts colonially in rock crevices on the face of steep rocky cliffs, rock outcrops, and abandoned quarries. This species has been known to occasionally roost in buildings and palm trees; however, roosting in these structures appears to occur temporarily during migration. Western mastiff bat forages primarily on large moths, also eating other insects including beetles, crickets, bees, dragonflies, cicadas, and plant bugs. This Biological Resources Technical Report 34 February 2025
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species forages over open habitats, including meadows, grasslands, ponds, reservoirs, bays, riparian zones, sometimes in urban environments opportunistically while traveling between higher quality habitats. Threats to this species include loss and fragmentation of rocky habitat through mining, water impoundments, and road construction, as well as poisoning from pesticide use.

Suitable foraging habitat is present above the open water in the Santa Ana River and Burris Basin and the narrow riparian fringes around Burris Basin and Former Ball Road Basin. The survey area offers an abundance of overpasses, bridges, and buildings with crevices suitable for temporary roosting by the western mastiff bat during foraging. A historical location for this species exists within 1 mile of the survey area, but none is known in the survey area (Figure 8) (CDFW 2025b).

5.4.6 Nesting Birds
The survey area contains suitable nesting habitat for several bird and raptor species protected under the CFGC and MBTA. The majority of the survey area is developed, and specific to the Santa Ana River, lined with concrete and riprap, devoid of vegetation suitable for most nesting birds and raptors. However, the survey area, particularly the Santa Ana River corridor, contains large expanses of open areas over slowly moving water suitable for insect- and aquatic-foraging bird species that may be attracted to the area for feeding and, therefore, may have higher potential to be found nesting within the survey area. The highest-quality suitable nesting habitat for riparian species occurs in the northwestern portion of the survey area, specifically the southern willow scrub, non-native woodland, disturbed mulefat scrub along the fresh open water of Burris Basin, and within the emergent wetland and southern willow scrub in Former Ball Road Basin. Suitable nesting habitat for cavity nesters is present in the trees, both native and ornamental, and structures throughout and surrounding the survey area. A large amount of avian activity was observed in the southern willow scrub of Former Ball Road Basin, including red-winged blackbirds (Agelaius phoeniceus), a yellow warbler, and a least Bell’s vireo. The riprap-lined banks of the Santa Ana River channel and the shores of Burris Basin and Former Ball Road Basin also serve as suitable nesting habitat for ground-nesting shorebirds, such as killdeer (Charadrius vociferus), of which many were observed perching on the deposited sediment “islands” and banks in the river channel during the 2023 surveys. Forster’s terns (Sterna forsteri) were observed hunting mosquito fish within the Santa Ana River channel and could be utilizing the deposited sediment islands or other shoreline habitats in the survey area for nesting. Additionally, human-made infrastructure, such as light posts, building ledges, and overpasses provide potential nesting habitat for birds and raptors.

Large colonies of cliff swallows (Petrochelidon pyrrhonota) were observed nesting under the Ball Road overpass in the survey area. Nesting materials were observed on parking lot light posts immediately west of the survey area in the Honda Center parking lot and were likely used by nesting osprey (Pandion haliaetus) hunting in the Santa Ana River corridor or the OCWD Basins.

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5.4.7 Roosting Bats
The survey area contains suitable roosting and foraging habitat for both common and sensitive bat species. Several concrete bridge overpasses span the width of the Santa Ana River channel and provide crevices suitable for structure-dwelling bats, including Mexican long-tongued bat (Choeronycteris mexicana) and big brown bat (Eptesicus fuscus). Ornamental and native tree species present on either side of the river channel also provide suitable roosting habitat for tree-roosting bats, such as such as the hoary bat (Lasiurus cinereus), western red bat (Lasiurus blossevillii), and western yellow bat (Lasiurus xanthinus). Further, these potential roosting sites are in proximity to open water where bats that forage on insects over sources of open water, such as the western mastiff bat. While no bats were observed using the survey area for roosting or foraging during the biological resource surveys, no nighttime focused acoustic surveys were conducted, and the availability of suitable habitat indicates bats are likely roosting and foraging in the survey area.

5.4.8 Wildlife Corridors and Habitat Linkages
Wildlife corridors provide routes for local movement and also regional linkages and corridors, often following linear topographical, vegetation, or water features. These corridors can be continuous habitats features or “steppingstone” areas, providing critical rest and foraging areas for, for example, birds traveling along migratory routes. Local routes of movement provide constant connections to resources that include sources of water, home/cover sites, and foraging areas. Regional linkages and movement corridors provide larger patches of open space to allow relatively free movement of wildlife species along multiple paths between important resources. These areas allow for not only long-term genetic flow between subpopulations but also critical pathways of seasonal/migratory movements. Larger predatory mammals often use regional corridors for hunting and reproduction needs. Potential wildlife corridors can include streams, riparian areas, and culverts under roadways. Habitat characteristics considered in the 2023 survey included topography, habitat quality, and adjacent land uses.

The survey area is likely to be used as a wildlife movement corridor and provides suitable nesting, foraging, and dispersal areas primarily for highly mobile species like bats and birds, and some movement opportunities for mammals. The area surrounding the survey area consists of dense urban development which restricts movement for many small mammals, amphibians, and reptiles.

Mesocarnivores and medium-sized mammals, such as raccoon (Procyon lotor), coyote (Canis latrans), or bobcat (Lynx rufus), have some potential to utilize the access roads that border the Santa Ana River channel for movement and may use the channel as a water source when moving through the area. The Santa Ana River flows from the northeast and has upstream connection to large open space preserves such as Chino Hills State Park and Santiago Oaks Regional Park, approximately 8 and 5 miles northeast, respectively. The Santa Ana River channel is one of the widest and longest uninterrupted paths to these open space areas through the dense urban sprawl of Orange County, and while high quality native habitat is scarce, it presents a viable route of movement through these areas.

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The survey area also holds value for migrating birds flying through to wintering grounds that are protected by the MBTA. The survey area is within the path of the Pacific Flyway, along which millions of birds, especially waterfowl, migrate annually between Alaska and Canada, through California, to Mexico and South America. The Santa Ana River corridor and surrounding freshwater basins provide an important stopover area for a large variety of birds during their annual migration. Open water attracts shorebirds including various terns, stilts, and egrets that utilize waterways to forage.

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Section 6 Impact Analysis

6.1 Significance Thresholds and Definition of Impacts
Appendix G of the CEQA Guidelines (CEQA Guidelines, Section 15000 et seq.) defines “significant effect on the environment” as a “substantial, or potentially substantial adverse change in the environment.” Appendix G of the CEQA Guidelines further indicates that there may be a significant effect on biological resources if the project would:

1. Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service.

2. Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, and regulations or by the California Department of Fish and Game or U.S. Fish and Wildlife Service.

3. Have a substantial adverse effect on state or federally protected wetlands (including, but not limited to marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means.

4. Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites.

5. Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance.

6. Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan.

Impacts to biological resources from implementation of the project are categorized quantitatively as direct and indirect impacts.

6.1.1 Direct Impacts
Direct impacts to biological resources occur when significant alterations or destruction occurs during the course of, or because of, project implementation. Examples of such impacts include removing, disturbing, or grading vegetation; dredging or grading a stream bank; filling wetlands with any materials; erecting any structures, including in a stream; and severing or physically restricting wildlife corridors and the distribution of individual species or resources. Other direct impacts may include loss of foraging or nesting habitat and loss of individual species as a result of habitat clearing.

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6.1.2 Indirect Impacts
Indirect impacts may include elevated levels of noise or lighting, change in surface water hydrology within a floodplain, and increased erosion or sedimentation. These types of indirect impacts can affect vegetation communities or their potential use by sensitive species. They can also cause the disruption of normal wildlife functions or activities, impacting individual species.

6.2 Threshold 1: Sensitive Plant and Wildlife Species

6.2.1 Guidelines for Determination of Significance
Significant impacts to sensitive plant and wildlife species could result if the project has a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special-status species in local or regional plans, policies, or regulations or by the CDFW and USFWS.

6.2.2 Impact Analysis

6.2.2.1 Sensitive Plant Species
Direct Impacts
No sensitive plant species were observed in the survey area during the 2023 survey. Further, none of the sensitive plant species analyzed in the literature and database review were determined to have a high potential to occur in the survey area. As discussed in Section 4.3, Survey Limitations, no focused sensitive plant species surveys were conducted in the survey area during the 2023 survey.

Implementation of the project would result in impacts primarily to developed land and non-native habitats, including the concrete and riprap-lined Santa Ana River channel, that do not provide suitable habitat for sensitive plant species. The native and aquatic habitats in the northern end of the project site are disturbed and have little to no potential to support sensitive plant species.

Therefore, direct impacts to sensitive plant species are considered less than significant, and no mitigation is required.

Indirect Impacts
No sensitive plant species were identified during the survey within the survey area, therefore, no temporary construction or long-term operational indirect impacts to sensitive plant species are anticipated. Temporary indirect impacts to sensitive plant species, if present, could result during construction of the project, and may include dust, which could disrupt plant vitality in the short term, or construction-related soil erosion and runoff that may permanently impact plant viability.

Permanent edge effects may include intrusions by humans and therefore possible trampling of individual plants, invasion by exotic plant and wildlife species, exposure to urban pollutants (fertilizers, pesticides, herbicides, and other hazardous materials), soil erosion, litter, and Biological Resources Technical Report 39 February 2025
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hydrologic changes (e.g., surface and groundwater level and quality). However, the project site and surrounding area already consist of disturbed habitat and urban uses subject to these edge effects. The project would be required to be in compliance with the National Pollutant Discharge Elimination System (NPDES) regulations through implementation of site design, source control, and incorporation of construction and permanent Best Management Practices (BMPs). The project’s consistency with the Goals and Policies in both the City of Anaheim General Plan Green Element and the City of Orange General Plan Natural Resources Element is demonstrated in Tables 2 and 3. Consistency with the General Plan’s goals and policies applicable to biological resources ensures further minimization of indirect impacts from implementation of the project.

Therefore, indirect impacts to sensitive plants during construction activities and operation of the project are less than significant, and no mitigation is required.

6.2.2.2 Sensitive Wildlife Species
Direct Impacts
The four sensitive wildlife species that were observed during survey and the two additional sensitive wildlife species that were determined to have a high potential to occur in the survey area are described in Sections 5.4.4, Sensitive Wildlife Species Observed, and 5.4.5, Sensitive Wildlife Species Not Observed with a High Potential to Occur (Figures 8 and 9). The sensitive wildlife species observed in the survey area, American white pelican, double-crested cormorant, least Bell’s vireo, and yellow warbler, were observed in the northern portion of the survey area, primarily within the Santa Ana River channel and Former Ball Road Basin. Least Bell’s vireo and yellow warbler were observed calling in the survey buffer, outside the project site, in the southern willow scrub in Former Ball Road Basin during the 2023 survey (Figure 9). American white pelican and double-crested cormorant were observed foraging in the northern end of the Santa Ana River channel. In addition, two sensitive wildlife species, American peregrine falcon and western mastiff bat, were not observed but determined to have a high potential to forage in the survey area.

The project has the potential to directly impact these species during construction activities through temporary displacement of individual wildlife or temporarily disrupt portions of their habitat (foraging habitat for American white pelican, double-crested cormorant, American peregrine falcon, and western mastiff bat, and suitable nesting and foraging habitat for least Bell's vireo and yellow warbler). While implementation of the project would result in temporary direct loss of habitat, including nesting and foraging habitat, for many of the sensitive wildlife species observed or with a high potential to occur in the survey area, the project proposes improvements to the Santa Ana River corridor, including aquatic and upland habitat restoration. Therefore, implementation of the project would result in a permanent increase in potentially suitable nesting and foraging habitat for sensitive wildlife species.

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Potential temporary direct impacts to the sensitive wildlife species observed or determined to have a high potential to occur are discussed below. An analysis of the exact acreage of temporary impacts that would occur to these sensitive wildlife species in the survey area as a result of the project is not provided at the programmatic level because such analysis would be speculative in nature since not all future site-specific projects are known at this time. Future project-specific analysis would be conducted in the review phase of the project, and any impacts to these sensitive wildlife species would be avoided, minimized, or mitigated as conditions of project approval prior to the implementation of the future site-specific projects.

Approximately 83.88 acres of aquatic communities, including fresh water, freshwater emergent wetland, and non-vegetated channel, occur in the survey area (Table 4). Of this total, approximately 77.81 acres of aquatic communities occur on the project site and have the potential to be temporarily impacted during project implementation. These aquatic communities provide suitable foraging habitat for sensitive American white pelican and double-crested cormorant, both observed using the Santa Ana River corridor in the northern portion of the survey area. These habitats also provide suitable foraging habitat for American peregrine falcon and western mastiff bat, both determined to have a high potential to occur in the survey area. The Santa Ana River corridor (defined as a non-vegetated channel), in particular, provides a wide, open area above fresh water which American peregrine falcon and western mastiff bat can use as foraging habitat. Direct temporary impacts to fresh water, freshwater emergent wetland, and non-vegetated channel could result in direct impacts to American white pelican double-crested cormorant, American peregrine falcon, and western mastiff bat in the form of temporary loss of foraging habitat. Therefore, potential temporary direct impacts to these sensitive wildlife species would be potentially significant without mitigation.

The 3.17 acres of scrub and riparian scrub vegetation communities, including Diegan coastal sage scrub, mulefat scrub (disturbed), and southern willow scrub. Although they are of low quality, these communities have the potential to provide some suitable nesting and foraging habitat for sensitive wildlife species. Of this total, approximately 1.25 acres of scrub and riparian scrub vegetation communities occur on the project site and have the potential to be temporarily impacted during project implementation. Least Bell’s vireo and yellow warbler were observed using the southern willow scrub in Former Ball Road Basin in the northwestern portion of the survey area. There is potential for least Bell’s vireo and yellow warbler to use these vegetation communities in both Burris Basin and Former Ball Road Basin by moving across Ball Road, which separates the two stands of southern willow scrub. Direct temporary impacts to Diegan coastal sage scrub, mulefat scrub (disturbed), and southern willow scrub could result in direct impacts to least Bell’s vireo and yellow warbler in the form of temporary loss of foraging habitat.

Therefore, potential temporary direct impacts to these sensitive wildlife species would be potentially significant without mitigation.

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The 0.22 acre of non-native woodland is limited to a narrow stand between The Islands Golf Center putting green and Burris Basin in the northwestern portion of the project site and does not provide high-quality nesting, roosting, or foraging habitat for the sensitive wildlife species observed or with a high potential to occur in the survey area. Therefore, potential impacts to sensitive wildlife species from removal of the non-native woodland would be less than significant, and no mitigation is required.

The 6.35 acre of disturbed habitat and 74.62 acres of developed land throughout the survey area provides little to no suitable habitat value for the sensitive species observed or with a high potential to occur in the survey area. However, a large number of overpasses, bridges, and buildings with crevices are present within the developed land that could provide suitable temporary roosting habitat for the western mastiff bat foraging on the project site. Potential impacts to western mastiff bat roosting habitat are discussed further under Sensitive Roosting Bats section below. Therefore, direct temporary impacts to other sensitive wildlife species are unlikely. Potential impacts to sensitive wildlife species would be less than significant, and no mitigation is required.

Indirect Impacts
Temporary construction-related and long-term operational indirect impacts to wildlife generally include lighting, increased human activity, hydrologic quality (increased turbidity, excessive sedimentation, flow interruptions, and changes in water temperature), noise, vibration, and trash and garbage, which can attract both introduced terrestrial and native terrestrial and avian predators (such as American crows [Corvus brachyrhynchos], common ravens [Corvus corax], coyotes, domestic dogs [Canis familiaris], raccoons, and striped skunks [Mephitis mephitis]). These indirect impacts in the form of habitat disturbance and potential predation could have a significant impact on the sensitive wildlife species observed or determined to have a high potential to occur in the survey area, identified in Sections 5.4.4 and 5.4.5. As previously discussed in Section 6.1.2, Indirect Impacts, the project and subsequent project approvals would be required to be in compliance with the NPDES regulations, through implementation of site design, source control, and incorporation of construction and permanent BMPs. The project’s consistency with the City of Anaheim General Plan Green Element Policies and Goals is demonstrated in Table 2. Consistency with the General Plan Green Element ensures minimization of indirect impacts from implementation of the project. Therefore, indirect impacts to sensitive wildlife during construction activities and operation of the project would be less than significant, and no mitigation is required.

Nesting Birds
The project site consists primarily of the concrete- and riprap-lined Santa Ana River channel, which provides limited habitat suitable for nesting birds protected under the CFGC and MBTA.

The majority of the highest-quality suitable nesting habitat occurs in the northwestern portion of the survey buffer, outside the project site, specifically the southern willow scrub, non-native Biological Resources Technical Report 42 February 2025
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woodland, and disturbed mulefat scrub along the fresh open water of Burris Basin, and within the emergent wetland and southern willow scrub in Former Ball Road Basin. A large amount of avian activity was observed within the vegetation in the survey buffer, including red-winged blackbird, least Bell’s vireo, and yellow warbler, observed in the southern willow scrub of Former Ball Road Basin. In addition, the ornamental trees within the non-native woodland surrounding Burris Basin in the northwestern portion of the project site may provide suitable nesting habitat for bird and raptor species. No active nests or nesting behavior were observed during the 2023 biological survey. Focused nest surveys were not conducted due to the programmatic nature of the project.

As previously discussed under Section 6.1.1, Direct Impacts, the project would be required to implement regulations protecting sensitive nesting birds, including the CFGC and MBTA.

Implementation is ensured though conditions of subsequent project-level approval. Due to known presence of federal and state endangered avian species, potential temporary direct impacts to these sensitive nesting birds protected under the CFGC and MBTA are considered potentially significant without mitigation.

Sensitive Roosting Bats
As previously discussed, suitable roosting habitat for sensitive bat species, including western mastiff bat, Mexican long-tongued bat, hoary bat, big brown bat, and western red bat, occurs in the structures and ornamental trees within the developed land throughout the survey area. Although roosting bats were not observed during the biological surveys, the availability of suitable roosting with nearby foraging habitat suggest roosting is likely occurring in the survey area. No focused nighttime mist-netting or acoustic surveys were conducted. As described in Section 2.2, Project Description, the majority of the developed land uses currently in the survey area would remain in place, and no impacts would result to the potential roosting habitat provided by the trees or structures those areas. Any potential direct impacts to the developed land in the survey area, particularly removal of any bridges, overpasses, or ornamental trees, could result in direct impacts to sensitive bats in the form of permanent and temporary roosting habitat loss. Potential impacts to sensitive roosting bat species during construction are considered potentially significant without mitigation.

6.2.3 Mitigation Measures

6.2.3.1 Sensitive Plant Species
Direct Impacts
No mitigation is required.

Indirect Impacts
No mitigation is required.

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6.2.3.2 Sensitive Wildlife Species
Direct Impacts
Significant direct impacts to sensitive wildlife species could result during project construction in the species’ suitable habitat. Implementation of Mitigation Measure BIO-1 would reduce potential impacts to sensitive wildlife species through conducting monitoring by a qualified biologist during construction of the project.

MM BIO-1 Qualified Monitoring Biologist. Before the start of construction activities, the City of Anaheim project manager (or designee) shall retain a qualified monitoring biologist to implement required monitoring and document the names and resumes of the people involved in the biological monitoring of the project and a schedule for the proposed work.

The qualified monitoring biologist shall be responsible for the following monitoring and reporting tasks:
• Biological Construction Mitigation/Monitoring Exhibit. Before the start of construction within the future site-specific proposed survey area, the qualified monitoring biologist shall submit a Biological Construction Mitigation/Monitoring Exhibit, which includes limits of work, proposed monitoring schedule, bird, focused sensitive species, or other wildlife surveys/survey schedules (including general avian nesting and U.S. Fish and Wildlife Service protocol), timing of surveys, bird construction avoidance areas/noise buffers/barriers, other impact avoidance areas, and any subsequent requirements determined by the qualified monitoring biologist. The Biological Construction Mitigation/Monitoring Exhibit shall include the construction site plan, written and graphic depiction of the project’s biological mitigation/monitoring program, and a schedule for construction activities. Where the potential for impacts to biological resources is limited (e.g., construction within a footprint that consists entirely of previously developed or disturbed lands), the Biological Construction Mitigation/Monitoring Exhibit may be limited to a pre- and post-maintenance verification inspection. For highly sensitive resource areas, full-time biological monitors may be required. The Biological Construction Mitigation/Monitoring Exhibit shall be approved by the City of Anaheim project manager (or designee) before the start of construction. • Avian Protection. To avoid any direct impacts to raptors and/or any migratory birds protected under the Migratory Bird Treaty Act, removal of habitat that supports active nests on the proposed area of disturbance should occur outside the breeding season for these species (January 15 to August 31). If removal of Biological Resources Technical Report 44 February 2025
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habitat on the proposed area of disturbance must occur during the breeding season, the monitoring biologist shall conduct a pre-construction survey to determine the presence or absence of nesting birds on the proposed area of disturbance. The pre-construction survey must be conducted within 10 calendar days before the start of construction, the results of which must be submitted to the City of Anaheim project manager (or designee) for review and approval before initiating any construction activities. If nesting birds are detected, a letter report or mitigation plan as deemed appropriate by the City of Anaheim shall be prepared and include proposed measures to be implemented to ensure that disturbance of raptor and bird breeding activities are avoided. The report or mitigation plan shall be submitted to the City of Anaheim for review and approval and implemented to the satisfaction of the City of Anaheim. The monitoring biologist shall verify and approve that all measures identified in the report or mitigation plan are in place prior to and/or during construction. • Resource Marking/Protection. Prior to the start of construction activities within the future site-specific proposed survey area, the qualified monitoring biologist shall supervise the placement of orange construction fencing or similar visible marker, staking, or flagging along the limits of the construction area, particularly where adjacent to sensitive biological avoidance areas, as shown on the Biological Construction Mitigation/Monitoring Exhibit to ensure crews remain within the approved construction limits. These demarcations shall not be required for areas with existing barriers, such as chain-link fencing, along the limits or facilities that are within and/or adjacent to developed and non-sensitive habitat areas. This task shall include flagging plant specimens and delineating buffers to protect sensitive biological resources (e.g., habitats, sensitive plant and wildlife species, including nesting birds) prior to construction. • Cover Trenches. The qualified monitoring biologist shall oversee the construction site so that cover and/or escape routes for wildlife from excavated areas shall be provided daily. Steep trenches, holes, and excavations during construction shall be covered at night with backfill, plywood, metal plates, or other means, and if plastic sheeting is used, the edges must be covered with soils such that small wildlife cannot access the excavated hole. Soil piles shall be covered at night to prevent wildlife from burrowing in. Sandbags shall weigh down the edges of the sheeting. These areas may also be fenced to prevent wildlife from gaining access.

Exposed trenches, holes, and excavations shall be inspected twice daily (i.e., each morning and before sealing the exposed area) by the qualified monitoring biologist to monitor for wildlife entrapment. Excavations shall provide an earthen ramp to allow for a wildlife escape route. The qualified monitoring biologist shall Biological Resources Technical Report 45 February 2025
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verify that the contractor has covered all steep-walled trenches or excavations prior to the end of construction daily. If wildlife species are encountered within any trenches or excavated areas, the qualified monitoring biologist shall remove them, if possible, or provide them with a means of escape (e.g., a ramp or sloped surface at no greater than a 30-degree angle) and allow the species to disperse. In addition, the qualified monitoring biologist shall train construction personnel to increase awareness of the possible presence of wildlife beneath vehicles and equipment and to use best judgment to avoid killing or injuring wildlife (refer to Pre-Construction Meeting/Education).
• Structure Clearance. Before the issuance of any permit to allow for the removal or demolition of trees on the project site (particularly any ornamental trees in the developed land areas), the qualified monitoring biologist shall conduct clearance surveys to flush out any wildlife species nesting, roosting, or otherwise occupying the trees. If wildlife species are encountered within any of the trees (outside the general bird nesting season), the qualified monitoring biologist shall remove them, if possible, or provide them with a means of escape and allow the species to disperse. If tree-roosting bats are suspected, slow removal by gently pushing the tree over with heavy equipment is required. • Pre-Construction Meeting/Education. Before the start of any construction activity where the site plan for the construction area indicates that significant impacts to biological resources may occur, a pre-construction meeting shall be held on site with the following in attendance: City of Anaheim project manager (or designee), the construction contractor (if applicable), and the qualified monitoring biologist.

At this meeting, the qualified monitoring biologist shall identify and discuss the construction protocols that apply to the proposed activities and the sensitive nature of the adjacent habitat with appropriate project personnel.

At the pre-construction meeting, the qualified monitoring biologist shall submit to the construction contractor a copy of the Biological Construction Mitigation/Monitoring Exhibit that identifies areas to be protected, fenced, and monitored. This data shall include all buffer limits, if applicable.

Before the start of construction activities, the qualified monitoring biologist shall meet with the construction contractor and crew and conduct an on-site educational session regarding the need to avoid impacts outside the approved construction footprint and to protect sensitive plants and wildlife that may occur at the specific facility. This may include but not be limited to explanations of the avian and aquatic resource buffers, the flag system for retention of sensitive plants, and clarification of acceptable access routes/methods and staging areas.

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• Biological Monitoring and Reporting. The qualified monitoring biologist shall inspect/monitor the project construction area in accordance with the approved Biological Construction Mitigation/Monitoring Exhibit. This may be limited to pre- and post-maintenance inspections, weekly visits, or full-time monitoring, as determined by the qualified monitoring biologist.

The qualified monitoring biologist shall document monitoring events via a Consultant Site Visit Record. This record shall be sent to the project manager each month. However, if weekly reports are submitted as part of a separate agency permit requirement, these reports may be forwarded to the project manager in place of Consultant Site Visit Record submittals.

If no deviations from the construction site plan occur during maintenance, no additional documentation is required. However, if deviations from the site plan do occur, such as unanticipated impacts to sensitive vegetation communities or unanticipated discharge of pollutants, a Final Monitoring Report shall be prepared within 3 months following the completion of mitigation monitoring detailing maintenance and monitoring that occurred and any remedial or compensatory measures taken.

Direct impacts to vegetation communities used by sensitive wildlife species would be conserved or restored through the implementation of Mitigation Measures BIO-2 and Mitigation Measure BIO-3.

These mitigation measures provide mitigation or revegetation for impacts to sensitive vegetation communities and jurisdictional aquatic resources that support sensitive wildlife species in the survey area.

MM BIO-2 Sensitive Vegetation Communities and Jurisdictional Aquatic Resources Impacts Mitigation. Any direct impacts to sensitive vegetation communities or jurisdictional aquatic resources would require mitigation to comply with state and/or federal authorizations in accordance with the minimum ratios described in the following table and the ratios defined in any state and/or federal permit(s) issued for the project.

Mitigation Ratios for Potential Impacts to Sensitive Vegetation Communities and Jurisdictional Aquatic Resources within the Survey Area Vegetation Community Jurisdiction Minimum Mitigation Ratio Fresh Water USACE/RWQCB/CDFW 2:1
Freshwater Emergent Wetland USACE/RWQCB/CDFW 2:1
Non-Vegetated Channel USACE/RWQCB/CDFW 2:1
Diegan Coastal Sage Scrub CDFW 2:1
Mulefat Scrub (Disturbed) CDFW 2:1
Southern Willow Scrub USACE/RWQCB/CDFW 2:1
Notes: CDFW = California Department of Fish and Wildlife; RWQCB = Regional Water Quality Control Board; USACE = U.S. Army Corps of Engineers
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• Potential direct impacts to sensitive vegetation communities, including jurisdictional aquatic resources, resulting from project implementation shall be mitigated through one of the following two options:
− Project compensatory mitigation for proposed impacts to sensitive vegetation communities, including jurisdictional aquatic resources, shall be provided through in-kind and on-site creation, enhancement, and/or restoration. A Habitat Mitigation and Monitoring Plan shall be provided and prepared in accordance with the City of Anaheim and regulatory agency requirements. − Compensatory mitigation requirements that are not able to be satisfied through on-site creation, enhancement, and/or restoration shall be satisfied through the acquisition of mitigation bank credits via a resource agency-approved mitigation site within the Santa Ana River Watershed or by acquisition of other approved off-site mitigation credits. Prior to implementation of project construction impacts that would require compensatory mitigation, documentation demonstrating the availability of mitigation credits (i.e., credit ledger) at the approved mitigation site must be submitted to the City of Anaheim project manager (or designee) for confirmation.

When proposed mitigation involves habitat enhancement, restoration, or creation, the Habitat Mitigation and Monitoring Plan shall include the following information:
• Conceptual planting plan including planting zones, grading, and irrigation. • Seed mix/planting palette.
• Planting specifications.
• Monitoring program including success criteria.
• Long-term maintenance and preservation plan.

For mitigation that involves habitat acquisition, the Habitat Mitigation and Monitoring Plan shall include the following:
• Location of proposed acquisition.
• Description of the biological resources to be acquired, including support for the conclusion that the acquired habitat mitigates for the specific maintenance impact and satisfies the requirement of no net loss. • Documentation that the mitigation area would be adequately preserved and maintained in perpetuity.

The identification of mitigation site credits shall be provided to the City of Anaheim project manager (or designee) and shall include the following:
• Location of approved mitigation site.

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• Description of the mitigation credits to be acquired, including support for the conclusion that the acquired habitat mitigates for the specific maintenance impact and satisfies the requirement of no net loss. • Documentation of the credits that are associated with a mitigation bank, which has been approved by the appropriate resource agencies. • Documentation in the form of a current mitigation credit ledger.

MM BIO-3 Habitat Restoration in Temporary Impact Areas. Temporary direct impact areas shall be restored to pre-construction topographic contours and conditions, including the revegetation of native plant communities, where appropriate. Habitat restoration and erosion control treatments shall be installed within these short-term impact areas.

Habitat revegetation shall feature native species that are typical of the area, and associated erosion control best management practices shall include silt fence and microplastic- and weed-free straw fiber rolls, where appropriate. The revegetation areas shall be monitored and maintained for 25 months to ensure adequate establishment and sustainability of the plantings/seedings.

Where a project activity involves potential disturbance of non-native invasive plant species (as identified by the California Invasive Plant Council), these plants shall be entirely removed where feasible, and the removal shall be monitored by the qualified monitoring biologist to ensure that dispersal of propagules (e.g., seeds, stems, etc.) are avoided or minimized. Where removal of plant roots is not feasible (e.g., where erosive flows are predicted), aboveground plant material shall be fully removed and monitored by the qualified monitoring biologist. Where aboveground plant material cannot be removed (e.g., due to limited access), herbicides shall be applied by a licensed pest control advisor, using chemicals permitted as safe within aquatic environments.

Significant direct impacts could result to sensitive least Bell’s vireo and yellow warbler during project construction in these species’ suitable habitat. Implementation of Mitigation Measure BIO-4 would reduce potential impacts to these sensitive wildlife species through focused species surveys by a qualified biologist prior to the start of project construction.

MM BIO-4 Least Bell’s Vireo and Yellow Warbler Pre-Construction Surveys. For any work proposed in or near suitable habitat between February 15 and August 15 (March 15 and September 15 for least Bell’s vireo), a pre-construction survey for least Bell’s vireo and yellow warbler shall be performed to reaffirm the presence and extent of occupied habitat. The pre-construction survey area for the species shall encompass all potentially suitable habitat within the project work zone and a 300-foot survey buffer. The pre-construction survey shall be performed to the satisfaction of the City of Anaheim project manager (or their designee) by a qualified biologist familiar with the species. The results of the pre-construction survey shall be Biological Resources Technical Report 49 February 2025
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submitted in a report to the City of Anaheim project manager (or their designee) for review and approval before initiating any construction activities. If least Bell’s vireo or yellow warbler are detected, a minimum 300-foot buffer delineated by orange biological fencing shall be established around the detected species. In addition, on-site noise reduction/attenuation techniques shall be incorporated, as appropriate, to avoid impacts to breeding least Bell’s vireo and yellow warbler from elevated construction noise levels during the breeding season. The City of Anaheim project manager (or their designee) shall have the discretion to modify the buffer width depending on site-specific conditions. In addition, noise monitoring may be required to ensure that the elevated construction noise levels are appropriately attenuated at the edge of occupied habitat to a level that is not expected to adversely affect nesting bird behavior (i.e., not to exceed an hourly average of 60 A-weighted decibels or ambient whichever is greater, at the edge of occupied habitat).

Indirect Impacts
No mitigation is required.

6.2.4 Significance after Mitigation

6.2.4.1 Sensitive Plant Species
Direct Impacts
Direct impacts to sensitive plant species were determined to be less than significant, and no mitigation is required.

Indirect Impacts
Indirect impacts to sensitive plant species were determined to be less than significant, and no mitigation is required.

6.2.4.2 Sensitive Wildlife Species
Direct Impacts
Implementation of Mitigation Measure BIO-1 through Mitigation Measure BIO-4 would mitigate potential direct impacts to sensitive wildlife species and their habitats to below a level of significance through monitoring by a qualified biologist, providing mitigation ratios for acreage impacts, the creation and restoration of impacted vegetation communities, and pre-construction sensitive nesting bird surveys.

Implementation of Mitigation Measure BIO-1 would mitigate potential direct impacts to sensitive nesting birds and roosting bats to below a level of significance. This mitigation measure would Biological Resources Technical Report 50 February 2025
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require monitoring by a qualified biologist who is responsible for conducting pre-construction nesting bird surveys and identifying and flushing any roosting bats from trees prior to construction.

Indirect Impacts
Indirect impacts to sensitive wildlife species were determined to be less than significant, and no mitigation is required.

6.3 Threshold 2: Sensitive Vegetation Communities

6.3.1 Guidelines for Determination of Significance
A significant impact would result if the project had a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, or regulations or by the CDFW or USFWS.

6.3.2 Impact Analysis

6.3.2.1 Direct Impacts
A total of nine vegetation communities and/or land cover types occur in the survey area (Table 4) that cover a total of 161.89 acres. Construction of the project has the potential to impact six sensitive vegetation communities that occur in the survey area, including 6.63 acres of fresh water, 0.97 acre of freshwater emergent wetland, 76.28 acres of non-vegetated channel, 1.16 acres of Diegan coastal sage scrub, 0.38 acre of mulefat scrub (disturbed), and 1.63 acres of southern willow scrub.

An analysis of the exact acreage of impacts that would occur to the sensitive vegetation communities in the survey area as a result of the project is not provided at the programmatic level because such analysis would be speculative in nature since the future project specifics are not known at this time. As future project specifics come forward, project-specific analysis would be conducted in the review phase, and any impacts to sensitive vegetation communities would be avoided, minimized, or mitigated as conditions of project approval prior to the implementation of the future project. Potential impacts to sensitive vegetation communities from implementation of the project would be potentially significant and mitigation is required.

6.3.2.2 Indirect Impacts
Most of the indirect impacts to sensitive plant species described in Section 6.2, Threshold 1:

Sensitive Plant and Wildlife Species, also result in potentially significant indirect impacts to sensitive vegetation communities. As previously discussed in Section 6.2.2, Impact Analysts, under Sensitive Plant Species/Indirect Impacts, the project would be required to be in compliance with the NPDES regulations through implementation of site design, source control, and incorporation of construction and permanent BMPs. The project’s consistency with the City of Anaheim General Plan Green Element Policies and Goals is demonstrated in Table 2. Consistency with the General Plan Green Biological Resources Technical Report 51 February 2025
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Element ensures minimization of indirect impacts from implementation of the project. Therefore, indirect impacts to sensitive vegetation communities during construction activities and operation of the project would be less than significant, and no mitigation is required.

6.3.3 Mitigation Measures

6.3.3.1 Direct Impacts
Development of the project would result in potentially significant direct impacts to sensitive vegetation communities. Implementation of Mitigation Measure BIO-1 through Mitigation Measure BIO-3 (described in Section 6.2.3.2, Sensitive Wildlife Species) would reduce direct impacts to sensitive vegetation communities through monitoring by a qualified biologist, providing mitigation ratios for acreage impacts, creating new vegetation, and restoring impacted vegetation.

6.3.3.2 Indirect Impacts
No mitigation is required.

6.3.4 Significance after Mitigation

6.3.4.1 Direct Impacts
Implementation of Mitigation Measure BIO-1 through Mitigation Measure BIO-3 would reduce potential direct impacts to sensitive vegetation communities to below a level of significance through monitoring by a qualified biologist, adhering to required mitigation ratios for acreage impacts, and creating new vegetation communities and restoring impacted ones.

6.3.4.2 Indirect Impacts
Indirect impacts to sensitive vegetation communities were determined to be less than significant, and no mitigation is required.

6.4 Threshold 3: Jurisdictional Aquatic Resources

6.4.1 Guidelines for Determination of Significance
A significant impact would result if the project had a substantial adverse effect on state or federally protected wetlands (including but not limited to marsh, vernal pool, coastal wetland) through direct removal, filling, hydrological interruption, or other means of disturbance.

6.4.2 Impact Analysis

6.4.2.1 Direct Impacts
As discussed in Section 5.2, a total of 85.51 acres of non-wetland waters, freshwater emergent wetland, and riparian potentially under the jurisdiction of the USACE, RWQCB, and CDFW occur in the survey area. These potentially jurisdictional aquatic resources in the survey area include Biological Resources Technical Report 52 February 2025
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approximately 82.91 acres of non-wetland waters (Santa Ana River, Collin’s Channel, Burris Basin, and Former Ball Road Basin), 0.97 acre of wetland (emergent wetland in Former Ball Road Basin), and 1.63 acre of riparian (southern willow scrub in Burris Basin). As discussed in Section

6.3, Threshold 2: Sensitive Vegetation Communities, the project would result in direct impacts to the aquatic and riparian vegetation communities also potentially under the jurisdiction of the USACE, RWQCB, and CDFW. Further, the reach of the Santa Ana River in the survey area contains the SAR1 Levee System (Upstream Reach) and therefore is under the jurisdiction of the USACE pursuant to the Rivers and Harbors Act Section 408. An analysis of the exact acreage of impacts that would occur to wetlands in the survey area as a result of the project is not provided at the programmatic level because such analysis would be speculative in nature since future project specifics are not known at this time. As future project specifics come forward, project-specific analysis would be conducted in the review phase of the project, and any impacts to jurisdictional aquatic resources would be avoided, minimized, or mitigated as conditions of project approval prior to the implementation of the future site-specific projects.

As previously discussed in Section 3, Regulatory Framework, the project would be required to be in compliance with all federal, state, and local regulations protecting biological resources as a condition of subsequent project-level approvals. This includes complying with applicable federal and state regulations that ensure no net loss of aquatic resources, such as Section 404 of the federal CWA, Section 408 of the Rivers and Harbors Act, Section 1600 of the CFGC, and Porter−Cologne. The project would be required to obtain regulatory permits from the USACE, RWQCB, and CDFW and provide compensatory mitigation for impacts prior to the start of construction that would ensure that no net loss of resources would result from implementation of the project. Therefore, direct impacts to jurisdictional aquatic resources would be less than significant with mitigation incorporated.

6.4.2.2 Indirect Impacts
Most of the indirect impacts to sensitive plant species and sensitive vegetation communities described in Sections 6.2.1 and 6.2.2 would also result in potentially significant indirect impacts to jurisdictional aquatic resources. As previously discussed in Section 6.2.2, the project would be required to be in compliance with the NPDES regulations, through implementation of site design, source control, and incorporation of construction and permanent BMPs. The project’s consistency with the City of Anaheim General Plan Green Element Policies and Goals is demonstrated in Table 2. Consistency with the General Plan Green Element ensures minimization of indirect impacts from implementation of the project. Therefore, indirect impacts to jurisdictional aquatic resources during construction activities and operation of the project would be less than significant, and no mitigation is required.

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6.4.3 Mitigation Measures

6.4.3.1 Direct Impacts
Development of the project would result in potentially significant direct impacts to jurisdictional aquatic resources. Implementation of Mitigation Measure BIO-1 through Mitigation Measure BIO-3 (described under Sensitive Wildlife Species Direct Impacts Mitigation) would reduce direct impacts to jurisdictional aquatic resources through monitoring by a qualified biologist, providing mitigation ratios for acreage impacts, and restoring temporary impact areas.

6.4.3.2 Indirect Impacts
No mitigation is required.

6.4.4 Significance after Mitigation

6.4.4.1 Direct Impacts
Implementation of Mitigation Measure BIO-1 through Mitigation Measure BIO-3 would mitigate potential direct impacts to jurisdictional aquatic resources to below a level of significance through monitoring by a qualified biologist, adhering to required mitigation ratios for acreage impacts, and restoring temporary impact areas.

6.4.4.2 Indirect Impacts
Indirect impacts to jurisdictional aquatic resources were determined to be less than significant, and no mitigation is required.

6.5 Threshold 4: Wildlife Corridors and Habitat Linkages

6.5.1 Guidelines for Determination of Significance
A significant impact would result if the project interfered substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors or impede the use of native wildlife nursery sites.

6.5.2 Impact Analysis

6.5.2.1 Direct Impacts
As discussed in Section 5.4.8, Wildlife Corridors and Habitat Linkages, the survey area is likely used as a wildlife movement corridor and provides suitable nesting, foraging, and dispersal areas primarily for highly mobile species like bats and birds, and some movement opportunities for mammals. The dense urban development surrounding the survey area restricts movement opportunities for many small and large mammals, amphibians, and reptiles. However, mesocarnivores and medium-size mammals, such as raccoon, coyote, or bobcat, could utilize the access roads that Biological Resources Technical Report 54 February 2025
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border the Santa Ana River channel for movement and may use the channel as a water source when moving through the area. The Santa Ana River channel, the widest and longest uninterrupted path through the dense urban sprawl of Orange County connecting to open space areasto the north, presents a viable route of wildlife movement through the survey area. The survey area also holds value for migrating birds, protected by the MBTA, flying within the Pacific Flyway to their wintering grounds.

Project impacts are proposed primarily in areas adjacent to and within existing development and would only be temporary impacts that occur during construction activities in the survey area. All existing wildlife corridors would remain in place, and their quality increased after implementation of the project. Therefore, significant direct long-term impacts to wildlife corridors and habitat connectivity provided by the survey area are not expected to occur. While project activities may temporarily disrupt wildlife movement through the survey area, the project is not expected to have a significant impact on habitat linkage over the long-term because the overall habitat quality of the existing corridors would be maintained and improved following project implementation. Therefore, impacts to wildlife corridors and habitat connectivity would be less than significant, and no mitigation is required.

6.5.2.2 Indirect Impacts
Wildlife movement corridors and habitat connectivity would be impacted by many of the other indirect effects discussed in Section 6.2.2 for impacts to sensitive wildlife species. As previously discussed in that section, the project would be required to be in compliance with the NPDES regulations, through implementation of site design, source control, and incorporation of construction and permanent BMPs. The project’s consistency with the City of Anaheim General Plan Green Element Policies and Goals is demonstrated in Table 2. Consistency with the General Plan Green Element ensures minimization of indirect impacts from implementation of the project.

Therefore, indirect impacts to wildlife movement corridors and habitat connectivity during construction activities and operation of the project would be less than significant, and no mitigation is required.

6.5.3 Mitigation Measures

6.5.3.1 Direct Impacts
No mitigation is required.

6.5.3.2 Indirect Impacts
No mitigation is required.

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6.5.4 Significance after Mitigation

6.5.4.1 Direct Impacts
Direct impacts to wildlife movement corridors and habitat linkages within the project area were determined to be less than significant, and no mitigation is required.

6.5.4.2 Indirect Impacts
Indirect impacts to wildlife movement corridors and habitat linkages within the project area were determined to be less than significant, and no mitigation is required.

6.6 Threshold 5: Local Policies or Ordinances

6.6.1 Guidelines for Determination of Significance
A significant impact would result if the project conflicted with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance.

6.6.2 Impact Analysis
As discussed in Section 3.3.2, City of Anaheim General Plan, the project is located in the City of Anaheim; therefore, it is subject to the goals and policies in the City General Plan. The City General Plan element applicable to biological resources includes the Green Element. Table 2 documents the project’s consistency with the Green Element goals and policies applicable to biological resources on the project site. As demonstrated in Table 2, the project would be consistent with the City General Plan goals and policies. Therefore, impacts would be less than significant, and no mitigation is required.

6.6.3 Mitigation Measures
No mitigation is required.

6.6.4 Significance after Mitigation
Impacts from conflicts with the City General Plan Green Element goals and policies were determined to be less than significant, and no mitigation is required.

6.7 Threshold 6: Regional Conservation Planning

6.7.1 Guidelines for Determination of Significance
A significant impact would result if the project conflicted with the provisions of an adopted HCP, NCCP, or other approved local, regional, or state HCP.

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6.7.2 Impact Analysis
As discussed in Section 3.3, Local, although the City of Anaheim is enrolled NCCP/HCP, the project site is not within the boundaries of the NCCP/HCP and is therefore not subject to the requirements of the NCCP/HCP. Therefore, impacts to conservation planning would be less than significant, and no mitigation is required.

Although the project is not subject to the NCCP/HCP, the avoidance, minimization, and mitigation measures proposed in Section 6.2.3, Mitigation Measures, would reduce potentially significant impacts to sensitive plant and wildlife species, sensitive vegetation communities, and jurisdictional aquatic resources to a less than significant level.

6.7.3 Mitigation Measures
No mitigation is required.

6.7.4 Significance after Mitigation
Impacts to conservation planning were determined to be less than significant, and no mitigation is required.

6.8 Cumulative Impacts

6.8.1 Cumulative Threshold 1: Sensitive Plant and Wildlife Species The cumulative survey area specific to biological resources was defined by nearby surrounding areas with similar biological resources. Cumulative projects in the vicinity of the survey area would have the potential to result in impacts to sensitive plant and wildlife species, including loss of habitat. Cumulative projects that are proposed in the City would be similar to the project and would impact primarily developed land covers and could potentially include portions of undeveloped open space in the City. Implementation of these cumulative projects have the potential to result in impacts to sensitive plant and wildlife species. However, all projects proposed in the City, like the OC River Walk project, are required to comply with CEQA, including limiting impacts to biological resources. Through implementation of Mitigation Measures BIO-1 through BIO-4, the project would reduce temporary and permanent impacts to sensitive plant and wildlife species to less than significant and would therefore not contribute to cumulative impacts.

Therefore, cumulative impacts to sensitive plant and wildlife species would be less than significant with mitigation incorporated.

6.8.2 Cumulative Threshold 2: Sensitive Vegetation Communities As discussed in Section 6.8.1, Cumulative Threshold 1: Sensitive Plant and Wildlife Species, the project’s implementation of Mitigation Measures BIO-1 through BIO-3 (provided in Section 6.2.3) ensures the project, in combination with other cumulative projects within the City, would not result in Biological Resources Technical Report 57 February 2025
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cumulatively considerable impacts to biological resources, specifically sensitive vegetation communities. In fact, the project would provide a net benefit to the vegetation communities in the survey area by protecting and restoring the functions of the Santa Ana River aquatic and adjacent habitats. Therefore, because the project minimizes impacts to sensitive vegetation communities, it would not result in a cumulatively considerable impact to sensitive vegetation communities.

6.8.3 Cumulative Threshold 3: Jurisdictional Aquatic Resources As discussed in Section 6.8.1, the project’s implementation of Mitigation Measures BIO-1 through BIO-3 (provided in Section 6.2.3) ensures the project, in combination with other cumulative projects within the City, would not result in cumulatively considerable impacts to biological resources, specifically jurisdictional aquatic resources. In fact, the project would provide a net benefit to the vegetation communities in the survey area by protecting and restoring the functions of the Santa Ana River aquatic and adjacent habitats. Therefore, because the project minimizes impacts to jurisdictional aquatic resources, it would not result in a cumulatively considerable impact to jurisdictional aquatic resources. In addition, all cumulative projects with potential impacts to jurisdictional aquatic resources would be required to comply with applicable federal and/or state regulations that ensure no net loss of resources, such as Section 404 of the federal CWA, Sections 9, 10, and 408 of the Rivers and Harbors Act, Section 1600 of the CFGC, and Porter−Cologne.

Therefore, because the project minimizes impacts to jurisdictional aquatic resources and would comply with federal and state permitting regulations, the project would not result in a cumulatively considerable impact to jurisdictional aquatic resources.

6.8.4 Cumulative Threshold 4: Wildlife Corridors and Habitat Linkages As discussed in Section 6.5.2, Impact Analysis, the project is not expected to result in significant impacts on wildlife corridors and habitat linkages over the long term because the overall habitat quality of the existing corridors would be maintained following project implementation. Therefore, the project would not result in a cumulatively considerable impact to wildlife corridors and habitat linkages.

6.8.5 Cumulative Threshold 5: Local Policies or Ordinances As discussed in Section 6.6.2, the project’s demonstrated consistency with the applicable City of Anaheim General Plan Green Element goals and policies (provided in Table 2) ensures that the project, in combination with other cumulative projects within the City, would not result in cumulatively considerable impacts to biological resources. Therefore, because the project minimizes impacts to biological resources and demonstrates consistency with the City of Anaheim General Plan Green Element, the project would not result in a cumulatively considerable impact associated with a conflict with local policies and ordinances protecting biological resources.

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6.8.6 Cumulative Threshold 6: Regional Conservation Planning As discussed in Section 3.3, the project site is not within the boundaries of the NCCP/HCP and is therefore not subject to the requirements of the NCCP/HCP. Therefore, the project would not result in a cumulatively considerable impact associated with a conflict with a Habitat Conservation Plan.

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Section 7 References
American Ornithological Society. 2019. Sixtieth Supplement to the American Ornithological Society’s Check-List of North American Birds. The Auk 136 (3):1–23. July 1. Accessed February 2025. https://doi.org/10.1093/auk/ukz042.

Baldwin, B.G, D.H. Goldman, D.J Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken. 2012. The Jepson Manual: Higher Plants of California. University of California Press. Berkeley, California. January.

Calflora. 2025. Calflora Database. Accessed February 2025. https://www.calflora.org/entry/wgh.html.

Cal-IPC (California Invasive Plant Council). 2025. Invasive Plant Inventory. Accessed February 2025. https://www.cal-ipc.org/plants/inventory/.

CDFW (California Department of Fish and Wildlife). 2025a. Biogeographic Information and Observation System Database. Accessed February 2025. https://wildlife.ca.gov/ Data/BIOS.

CDFW. 2025b. California Natural Diversity Database. State and Federally Listed Endangered, Threatened, and Rare Plants of California. Accessed February 2025. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=109390&inline.

CDFW. 2025c. California Natural Community List. Updated June 1, 2023. Accessed February 2025. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=153398&inline.

CNPS (California Native Plant Society). 2025. Rare Plant Inventory. A Science-Driven Approach (online edition, v9.5). Accessed February 2025. http://www.rareplants.cnps.org/.

City of Anaheim. 2004. City of Anaheim General Plan. May 2004. Accessed February 2025. https://www.anaheim.net/712/General-Plan.

County of Orange. 1996. County of Orange Central and Coastal Subregion Natural Communities Conservation Plan/Habitat Conservation Plan. Approved July 1996. Accessed February 2025. https://planningandsustainability.uci.edu/community/pdf/nccp-ia-srchbl.pdf.

Crother, B.I. 2012. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in our Understanding, edited by J.J. Moriarty. 7th ed. Society for the Study of Amphibians and Reptiles (SSAR); Herpetological Circular no. 39. August 2012. Accessed February 2025. http://home.gwu.edu/~rpyron/publications/Crother_et_al_2012.pdf.

Holland, R.F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities of California. State of California, the Resources Agency, Department of Fish and Wildlife, Natural Heritage Division. October.

Jepson Online. 2025. “The Jepson Herbarium.” Accessed February 2025. https://ucjeps.berkeley.edu/eflora/.

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Moyle. 2002. Inland Fishes of California. Accessed February 2025. https://www.waterboards.ca.gov/water_issues/programs/tmdl/records/state_board/1998/re f2608.pdf.

NRCS (Natural Resources Conservation Service). 2025. National Water and Climate Center:

WETS Table. Accessed February 2025. https://www.wcc.nrcs.usda.gov/climate/ navigate_wets.html.

Shuford W.D. and T. Gardali, editors. 2008. Species Accounts: American White Pelican (Pelecanus erythrorhynchos). Excerpt from California Bird Species of Special Concern: A ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California. Studies of Western Birds 1. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento. Accessed February 2025. https://www.contracosta.ca.gov/DocumentCenter/ View/34166/Shuford-Gardali-2008-California-Bird-Species-of-Special-Concern-PDF.

SWRCB (State Water Resources Control Board). 2025. California Integrated Report (Clean Water Act Section 303(d) List and 305(b) Report). Accessed February 2025. https://www.waterboards.ca.gov/water_issues/programs/water_quality_assessment/2018_ integrated_report.html.

USACE (U.S. Army Corps of Engineers). 1987. Corps of Engineers Wetlands Delineation Manual.

Final report. Wetlands Research Program Technical Report Y-87-1 (online edition).

Prepared by Environmental Laboratory, U.S. Army Waterways Experiment Station.

Wetlands Research Program. January 1987. Accessed February 2025. https://www.lrh.usace.army.mil/Portals/38/docs/USACE%2087%20Wetland%20Delineat ion%20Manual.pdf.

USACE. 2008. Regional Supplement to the Corps of Engineers Wetlands Delineation Manual:

Arid West Region.

USACE. 2015. Santa Ana River 1 Levee System. August 2015. Accessed February 2025. https://www.spl.usace.army.mil/Portals/17/docs/LeveeSafetyProgram/San_Ana_ River_1_Levee_System_PI_Report_No-01_ES_M_20151023.pdf.

USACE. 2025. “TNWs & Navigable Waters in Los Angeles District.” Accessed February 2025. https://www.spl.usace.army.mil/Missions/Regulatory/JurisdictionalDetermination/Navigable-Waterways/.

USDA (U.S. Department of Agriculture). 2019. Web Soil Survey. Natural Resources Conservation Service, Soil Survey Staff. Last modified July 31. Accessed February 2025. http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm.

USDA. 2025. Web Soil Survey of Orange County Area, California. Accessed February 2025. https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx.

USFWS (U.S. Fish and Wildlife Service). 2021. National Wetlands Inventory Wetlands Mapper.

Last updated November 30. Accessed February 2025. https://www.fws.gov/wetlands/ Data/Mapper.html.

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USFWS. 2025a. National Wetlands Inventory Wetland Mapper. Accessed February 2025. https://www.fws.gov/wetlands/Data/Mapper.html.

USFWS. 2025b. Information for Planning and Consultation. Accessed February 2025. https://ipac.ecosphere.fws.gov/location/index.

USGS (U.S. Geological Survey). 2025. National Hydrologic Dataset. Accessed February 2025. https://www.arcgis.com/home/webmap/viewer.html?url=https://hydro.nationalmap.gov/a rcgis/rest/services/nhd/MapServer&source=sd.

Wilson and Reeder. 2005. Mammal Species of the World. Third Edition. http://www.departments.bucknell.edu/biology/resources/msw3/.

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Appendix A. Figures
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Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure1_Regional.mxd Dana
Point
San Juan
Capistrano
Laguna
Beach
Laguna
Hills Coto De
Caza
Newport
Beach Mission
Viejo
Trabuco
Highlands
Costa
Mesa
Irvine
Huntington
Beach
Tustin
Seal
Beach
Garden
Grove
Orange
Anaheim
Placentia Yorba Linda
Fullerton
Corona
March
Woodcrest AFB
Norco
Riverside
Rubidoux
Wildomar
Lake
Elsinore
Carson
Long
Beach
Cerritos
Gardena Bellflower Compton
Downey
Diamond
Bar
Industry
Walnut
Alhambra Covina
Pomona
Claremont
Glendora
Irwindale
Burbank Monrovia
Altadena
Pasadena Glendale
Acton
Chino
Hills
Chino
Loma
Linda
Ontario Bloomington Colton
Upland Fontana Rialto
Crestline
Hesperia
Victorville
Cypress
nglewood
Whittier
Commerce
Montebello
Rosemead
Arcadia
Los Angeles County
Orange County
San Bernardino County
Los Angeles County
Riverside County
Orange County
Orange County
San Diego
County
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Incorporated Areas
Project Site
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Regional Location
Source: ESRI 2020.

Figure 1 ± 0 5 10
Miles
Source: PACE Advanced Water Engineering 2024.

C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\1st Screencheck DEIR Figure 2
Local Vicinity
OC River Walk Project
Feet
N
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Project Site
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure3_USGS.mxd USGS Topographic Map
Source: USGS 7.5 Minute Anaheim and Orange Quadrangles 1974. ±
0 1,000 2,000 Figure 3
Feet
OC River Walk Project
ÄÆ57

HILDA ST

WINSTON RD

RILES CIR

POPLAR ST

BARKLEY AVE

PRIMROSE DR

DOUGLASS RD

SEQUOIA AVE

PHOENIX CLUB DR

SINCLAIR ST

OMEGA AVE

STRUCK AVE

CLIFPARK WAY

CARL ST
ELM ST

YALE AVE

TRENTON AVE

WALNUT AVE

DOUGLASS RD

ECKHOFF ST

ORANGEWOOD AVE

TAFT AVE

HOWELL AVE

COLLINS AVEMAIN ST

SUNKIST ST

CERRITOS AVE

GROVE AVE

BATAVIA ST

BALL RD

KATELLA AVE
Project Site
Soils
Metz Loamy Sand
Pits
Riverwash
Water
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure4_Soil.mxd Soils
Source: Eagle Imagery 2017.
± 0 500 1,000 Figure 4
Feet
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Aquatic Resource Type
Freshwater Emergent Wetland
Freshwater Forested/Shrub Wetland
Freshwater Pond
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Riverine
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure5_NWI.mxd Source: USFWS 2023; Maxar Imagery 2021.
±
0 1,000 2,000
Feet National Wetlands Inventory Results
Source: USFWS 2023; Maxar Imagery 2021.

Figure 5
OC River Walk Project
B u r r i s B a s i n
F o r m e r B a l l
R o a d B a s i n
S a n t a A n a R i v e r
C o l l i n ' s C h a n n e l
ÄÆ57
Project Site
100-Foot Buffer
Vegetation Communities and
Land Cover Types
Developed
Diegan Coastal Sage Scrub
Disturbed Habitat
Mulefat Scrub (Disturbed)
Emergent Wetland
Non-Native Woodland
Non-Vegetated Channel
Fresh Water
Southern Willow Scrub
Date: 7/9/2025 - Last saved by: Matthew.Dornbach - Path: C:\Users\matthew.dornbach\AppData\Local\Temp\ArcGISProTemp20108\Untitled\Untitled.aprx Vegetation Communities and Land Cover Types
Source: Maxar Imagery 2021.
±
0 500 1,000
Feet
OC River Walk Project
See Inset Map See Inset Map
B u r r i s B a s i n
Figure 6
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B u r r i s B a s i n
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Non-Wetland Waters
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Source: Maxar Imagery 2021.
±
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Figure 7
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Bird Species
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!( California Black Rail
!( California Least Tern
Fish Species
XW Steelhead - Southern California DPS
Mammal Species
") Western Mastiff Bat
Plant Species
*# Chaparral Sand-Verbena
Reptile Species
d
Coast Horned Lizard
Date: 2/25/2025 - Last saved by: Matthew.Dornbach - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\OCRiverWalk_BRTR\OCRiverWalk_BRTR.aprx ±
0 1,000 2,000
Feet Sensitive Species with Potential to Occur
Source: CNDDB 2023; Maxar Imagery 2021.

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Figure 8
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Wildlife Observations !( American White Pelican !( Double-Crested Cormorant !( Least Bell's Vireo !( Yellow Warbler Date: 7/10/2023 - La st saved by: Randy.Deodat - Pa th: C:\GIS \P rojects\Ci ty of A naheim \O C River Wal k\Map Docs\B io\B TR\Fig ure9 _SpeciesObserved.m xd Sensitive Species Observed
Source: Maxar Imagery 2021.
±
0 500 1,000 Figure 9
Feet
OC River Walk Project
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Appendix B. Species Observed
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Plant Species Observed
Scientific Name Common Name Special Status

GYMNOSPERMS
Pinaceae − Pine family
Pinus coulteri Coulter pine
Pinus jeffreyi Jeffrey pine

EUDICOTS
Adoxaceae − Muskroot family
Sambucus nigra ssp. caerulea Blue elderberry
Anacardiaceae − Sumac Or
* Schinus terebinthifolius Brazilian pepper tree
Asteraceae − Sunflower family
Ambrosia acanthicarpa Annual bur-sage
Artemisia californica California sagebrush
Baccharis pilularis ssp. pilularis Coyote brush
Baccharis salicifolia ssp. salicifolia Mulefat
* Centaurea melitensis Tocalote
* Erigeron bonariensis Flax-leaved horseweed
Heterotheca grandiflora Telegraph weed
Pseudognaphalium stramineum Cotton batting everlasting
* Verbesina encelioides ssp. exauriculata Golden crownbeard Boraginaceae − Borage family
Heliotropium curassavicum var. oculatum Alkali heliotrope Brassicaceae − Mustard family
* Brassica nigra Black mustard
Euphorbiaceae − Spurge family
Croton californicus California croton
* Ricinus communis Castorbean
Geraniaceae − Geranium family
* Erodium moschatum Whitestem filaree
Lamiaceae − Mint family
Salvia apiana White sage
Salvia clevelandii Fragrant sage
Salvia mellifera Black sage
Moraceae − Mulberry family
* Ficus carica Edible fig
Myrsinaceae − Myrsine family
* Anagallis arvensis Scarlet pimpernel
Scientific Name Common Name Special Status
Polygonaceae − Buckwheat family
Eriogonum fasciculatum California buckwheat
Salicaceae − Willow family
Salix gooddingii Goodding's black willow
Salix lasiolepis Arroyo willow
Solanaceae − Nightshade family
Datura wrightii Wright's jimsonweed
* Nicotiana glauca Tree tobacco
Verbenaceae − Vervain family
* Lantana camara Lantana

MONOCOTS
Arecaceae − Palm family
* Syagrus romanzoffiana Queen palm
* Washingtonia robusta Mexican fan palm
Cyperaceae − Sedge family
Schoenoplectus americanus American bulrush
Poaceae − Grass family
* Arundo donax Giant reed
* Hordeum vulgare Commercial barley
Legend
*= Non-native or invasive species
Special Status
Federal
FE = Endangered
FT = Threatened
State
SE = Endangered
ST =Threatened
CRPR – California Rare Plant Rank
1A. Presumed extinct in California and elsewhere
1B. Rare or Endangered in California and elsewhere
2A. Presumed extinct in California, more common elsewhere 2B. Rare or Endangered in California, more common elsewhere

3. Plants for which we need more information − Review List

4. Plants of limited distribution − Watch List
Threat Ranks
.1 − Seriously endangered in California
.2 – Fairly endangered in California
.3 – Not very endangered in California
Wildlife Species Observed
Scientific Name Common Name Special Status

INVERTEBRATES
Moths, Skippers, and Butterflies
Pontia protodice Checkered white
Vanessa annabella West coast lady
Hyles lineata White-lined sphinx
Estigmene acrea Salt marsh moth
* Hyles euphorbiae Leafy spurge hawk-moth

VERTEBRATES
Fish
Cyprinus carpio Common carp
Gambusia affinis Western mosquitofish
Micropterus sp. Bass
Amphibians
* Lithobates catesbeianus American bullfrog
Reptiles
Sceloporus occidentalis Western fence lizard
Birds
Branta canadensis Canada goose
* Alopochen aegyptiacus Egyptian goose
Anas platyrhynchos Mallard
Phalacrocorax auritus Double-crested cormorant WL
Pelecanus erythrorhynchos American white pelican SSC, BCC Ardea alba Great egret
Egretta thula Snowy egret
Nycticorax nycticorax Black-crowned night-heron
Cathartes aura Turkey vulture
Buteo jamaicensis Red-tailed hawk
Himantopus mexicanus Black-necked stilt
Recurvirostra americana American avocet
Charadrius vociferus Killdeer
Larus occidentalis Western gull
Sterna forsteri Forster's tern
* Streptopelia decaocto Eurasian collared-dove
*Zenaida macroura Mourning dove
Calypte anna Anna's hummingbird
Selasphorus sasin Allen's hummingbird
Tyrannus verticalis Western kingbird
Scientific Name Common Name Special Status
Vireo bellii pusillus Least Bell's vireo FE, SE
Corvus brachyrhynchos American crow
Corvus corax Common raven
Tachycineta bicolor Tree swallow
Petrochelidon pyrrhonota Cliff swallow
Hirundo rustica Barn swallow
Psaltriparus minimus Bushtit
Mimus polyglottos Northern mockingbird
Geothlypis trichas Common yellowthroat
Setophaga petechia Yellow warbler SSC
Melospiza melodia Song sparrow
Agelaius phoeniceus Red-winged blackbird
Icterus cucullatus Hooded oriole
Haemorhous mexicanus House finch
Carduelis psaltria Lesser goldfinch
* Vidua macroura Pin-tailed whydah
Mammals
Sylvilagus audubonii Desert cottontail
Spermophilus beecheyi California ground squirrel
Legend
*= Non-native or invasive species
Special Status
Federal
BCC = Bird of Conservation Concern
FE = Endangered
FT = Threatened
State
CFP = California Fully Protected Species
SE = Endangered
SSC = California Species of Special Concern
ST =Threatened
WL = California Watch List
Appendix C. Aquatic Resources Delineation Report
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Aquatic Resources
Delineation Report
Orange County River Walk Project
December 2023
Prepared for:

City of Anaheim
Community Services Department, Parks Division
200 S. Anaheim Boulevard, Suite 433
Anaheim, California 92805
Contact: Ana Straabe, Principal Project Planner
Prepared by:
600 B Street, Suite 2000
San Diego, California 92101
(619) 236-1778
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Table of Contents
Acronyms and Abbreviations ...................................................................................................iii Section A Site Description, Landscape Setting .................................................................... 1 A.1 Project Overview ............................................................................................. 1 A.1.1 Project Location ................................................................................... 1 A.1.2 Project Purpose ................................................................................... 2 A.1.3 Project Description............................................................................... 2 A.2 Project Site Access.......................................................................................... 2 Section B Site Alteration, Current, and Past Land Use........................................................ 5 B.1 Topography and Soils...................................................................................... 5 B.2 Hydrology ........................................................................................................ 6 B.3 Vegetation Communities and Land Cover Types ............................................ 7 B.3.1 Fresh Water......................................................................................... 7 B.3.2 Emergent Wetland ............................................................................... 7 B.3.3 Non-Vegetated Channel ...................................................................... 8 B.3.4 Southern Willow Scrub ........................................................................ 8 Section C Precipitation Data and Analysis............................................................................ 9 C.1 Climate and Growing Season.......................................................................... 9 C.2 Antecedent Precipitation Tool and Natural Resources Conservation Service Wetlands Climate Table Results Summary........................................ 9 C.3 Wetland Hydrology and Analysis...................................................................10 Section D Methods.................................................................................................................11 D.1 Pre-Field Review ...........................................................................................11 D.2 On-Site Aquatic Resources Delineation ........................................................11 D.3 On-Site Ordinary High Water Mark Investigation ..........................................13 D.4 Streamflow Duration Assessment ................................................................. 13 Section E Aquatic Resources Descriptions ........................................................................15 E.1 Non-Wetland Waters .....................................................................................15 E.1.1 Santa Ana River.................................................................................15 E.1.2 Collin’s Channel.................................................................................16 E.1.3 Orange County Water District Basin 1...............................................17 E.1.4 Orange County Water District Basin 2...............................................18 Section F Deviation from Local Wetlands Inventory or National Wetlands Inventory....21 Section G Mapping Method...................................................................................................23 Section H Conclusions..........................................................................................................25 Section I Preliminary Jurisdictional Determinations ........................................................27 Aquatic Resources Delineation Report ii December 2023
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Section J Disclaimer Statement...........................................................................................29 Section K References ............................................................................................................31 Tables
Table 1. Non-Wetland Waters in the Survey Area ......................................................................15 Table 2. Summary of Non-Wetland Waters in the Survey Area..................................................25 Table 3. Potential Jurisdiction of Aquatic Resources in the Survey Area ...................................28 Attachments
Attachment A. Figures
Attachment B. Statement of Access
Attachment C. Antecedent Precipitation Tool and NRCS WETS Table Results Attachment D. Arid West Ordinary High Water Mark Datasheets Attachment E. Photographic Log
Attachment F. Geographic Information Systems Data
Attachment G. ORM Bulk Upload Aquatic Resources Spreadsheet Aquatic Resources Delineation Report iii December 2023
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Acronyms and Abbreviations
°F degrees Fahrenheit
CDFW California Department of Fish and Wildlife
County County of Orange
GPS Global Positioning System
Harris Harris & Associates
NHD National Hydrography Dataset
NIDIS National Integrated Drought Information System
NRCS Natural Resources Conservation Service
NWI National Wetlands Inventory
OC River Walk Orange County River Walk
OCWD Orange County Water District
OHWM ordinary high water mark
project Orange County River Walk Project
RWQCB Regional Water Quality Control Board
SAR1 Levee Santa Ana River 1 Levee System
SART Santa Ana River Trail
TNW traditional navigable water
USACE U.S. Army Corps of Engineers
USGS U.S. Geological Survey
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Aquatic Resources Delineation Report 1 December 2023
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Section A Site Description, Landscape Setting
A.1 Project Overview
The City of Anaheim is the Lead Agency responsible for preparing a Draft Environmental Impact Report to analyze the impacts of the Orange County River Walk (OC River Walk) Project (project).

The project consists of various multi-purpose improvement opportunities that are identified in an effort to transform the Santa Ana River corridor and portions of the existing Santa Ana River Trail (SART) into an iconic location and experience. This Aquatic Resources Delineation Report documents the aquatic resources that occur on the project site and a 100-foot survey buffer (survey area).

A.1.1 Project Location
The project site is located along the Santa Ana River corridor, generally extending from Orangewood Avenue north to Ball Road and the existing Anaheim Coves at Burris Basin, encompassing approximately a 2-mile stretch and approximately 111 acres. The project site is adjacent to Angel Stadium, Anaheim Regional Transportation Intermodal Center, the Honda Center, and the Arena Corporate Center (ACC) buildings on the west side in the City of Anaheim (Appendix A, Figures; Figure 1, Regional Location, and Figure 2, Local Vicinity). On the east side, it is near the Sandra Hutchens Regional Law Enforcement Training Center (a facility that includes a combat shooting range), the Orange County Public Works offices, the Stadium Promenade shopping mall, the Extended Stay America – Orange, and the Kinder Morgan Orange Terminal in the City of Orange. The project site is located within the Cities of Anaheim and Orange, with many different landowners and jurisdictional bodies.

The majority of the project site includes the concrete-lined Santa Ana River corridor surrounded by urban development, including commercial, industrial, and residential uses, within the Cities of Anaheim and Orange (Figure 2). The Santa Ana River is within the Orange County Water District’s (OCWD) jurisdiction north of the Union Pacific Railroad (UPRR) and within the Orange County Flood Control District’s (OCFCD) jurisdiction south of the UPRR. Within the boundaries of the project site, five overcrossings and/or bridges span the Santa Ana River: Ball Road Bridge, UPRR overcrossing, Katella Avenue Bridge, Metrolink/Los Angeles-San Diego-San Luis Obispo Rail Corridor (LOSSAN Corridor) railroad overcrossing, and Orangewood Avenue Bridge.

Additionally, State Route (SR-) 57 crosses the Santa Ana River. The northern portion of the project site includes the Orange County Water District (OCWD) pump house, associated water detention basins, and the eastern portion of the Islands Golf Center. The project site’s northern boundary connects to the existing Anaheim Coves at Burris Basin..

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A.1.2 Project Purpose
The following objectives have been established for the project and will aid decision makers in their review of the project and associated environmental impacts:

1. Adopt the OC River Walk Conceptual Master Plan for OC River Walk Project to further enhance and accentuate existing recreational areas, facilitate pedestrian and bicycle access, and promote the use of the river corridor open space area for the community benefit.

2. Implement projects identified in the OC River Walk Conceptual Master Plan that will create visually appealing outdoor public amenities that will benefit and promote environmental and community health, recreation, safety, entertainment, wayfinding, art, education, cultural awareness, beauty, connectivity, water supply, economic, and natural resource needs.

3. Provide seamless and cohesive improvements across jurisdictions on the project site to benefit the public and the area’s aesthetics.

4. Implement projects to transform and improve the river and riverbed’s groundwater recharge potential and improve the river corridor’s ecology (flora and fauna).

5. Maintain and enhance flood protection capacity and resiliency.

6. Enhance connectivity and community access by leveraging the project site's location near ARTIC, major entertainment venues, and adjacent mixed-use developments..

A.1.3 Project Description
The project consists of consists of various multi-purpose improvements to transform the Santa Ana River corridor and portions of the existing Santa Ana River Trail, along with related off-site improvements necessary for its implementation. The main components of the Conceptual Master Plan involve creating two water impoundments by installing three inflatable rubber dams, modifying the riverbanks, constructing two pedestrian/bike bridges, providing new trails, improving existing trails, creating new and protection of existing access ramps, constructing two new undercrossings on the west bank at the Union Pacific Railroad and the Metrolink railroad, providing enhanced community amenities (e.g., terraced seating, nature play areas, parklets, plazas, gathering areas for large-scale events, festivals, and other activities, water access, kayak launch, etc.), and other improvements. These improvements would require the implementation of 19 project elements, which have been categorized into four groups: Group A – Impoundments, Storm Drain Diversions, and Embankments; Group B – New Pedestrian/Bike Bridges; Group C – New Trails and Trail Improvements; and Group D – Enhanced Community Recreation Amenities, as shown Table ES-1, Conceptual Master Plan Elements.

A.2 Project Site Access
The majority of the project site is publicly accessible on public roadways and the SART (Figure 2).

Starting from Interstate (I-) 5 north, take Exit 107A toward Pomona onto State Route 57 north and, after 2 miles, take Exit 3 for Ball Road, turn right, and then turn left into the Islands Golf Center Aquatic Resources Delineation Report 3 December 2023
OC River Walk Project
to access the northern portion of the project site. The remainder of the project site to the south includes the Santa Ana River corridor and can be accessed via the SART. The geographic coordinates for the northern and southern limits of the project site are approximately 33.821440°N, −117.870396°W and 33.795975°N, −117.878083°W, respectively (Attachment B, Statement of Access).

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Section B Site Alteration, Current, and Past Land Use
The survey area is in the highly developed eastern portion of the City of Orange, adjacent to the City of Anaheim (Figures 1 and 2). The Santa Ana River corridor, which makes up the majority of the survey area, is entirely concrete lined and has concrete riprap lining the riverbanks (Figure 2). The portion of the Santa Ana River in the survey area also contains the U.S. Army Corps of Engineers (USACE) constructed Santa Ana River 1 Levee System (SAR1 Levee System) (Upstream Reach) (USACE 2015). The SAR1 Levee System (Upstream Reach) is located on the right/northwest bank of the Santa Ana River in the cities of Anaheim and Orange. The SAR1 Levee System (Upstream Reach) extends from upstream of Yorba Linda Boulevard/Weir Canyon Road to upstream of the I-5 Freeway, a distance of approximately 11.04 miles. The SAR1 Levee System (Upstream Reach) has a levee embankment with a riverward slope lined with either riprap, grouted stone, reinforced concrete, or shotcrete reinforced with welded wire fabric. Other structures in the SAR1 Levee System (Upstream Reach) include wing walls, retaining walls, a floodwall, drop structures, grade stabilizers, 74 conduits associated with the side-drainage/diversion structures, numerous utility crossings, 16 bridge crossings, and 25 access ramps. The SAR1 Levee System (Upstream Reach) was federally authorized and subsequently constructed by the USACE, Los Angeles District. Construction of the SAR1 Levee System (Upstream Reach) was completed in 1999 and is now entirely operated and maintained by Orange County Flood Control District, which is administered by Orange County Public Works staff (USACE 2015).

Santa Ana River Flood Control was observed operating heavy construction equipment to actively move sediment in the bottom of the Santa Ana River during the 2023 aquatic resources delineation field survey. The northern portion of the survey area contains the OCWD pump house and associated water detention basins (OCWD Basins 1 and 2). The OCWD Basins 1 and 2, while artificially constructed, are earthen bottomed and support riparian and wetland vegetation.

The urban development in and surrounding the survey area, including the construction and maintenance of the SAR1 Levee System and other flood control infrastructure, has both disturbed and altered the natural flows through the survey area. These alterations include diverting and directing stormwater flows through detention basins and concrete-lined channels and culverts into the concrete- and riprap-lined Santa Ana River, which makes up the majority of the survey area.

B.1 Topography and Soils
The survey area is in a relatively flat urban setting, with the greatest elevation decreases occurring in the Santa Ana River corridor and the OCWD Basins 1 and 2 (Figure 2 and Figure 3, USGS Topographic Map). The survey area is depicted on the U.S. Geological Survey (USGS) 7.5-minute Anaheim quadrangle in Township 4 South, Range 10 West, Sections 13, 24, and 25 and the 7.5- minute Orange quadrangle in Township 4 South, Range 9 West, Sections 18 and 19 (Figure 3).

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The on-site elevation ranges from approximately 133 to 190 feet above mean sea level. The topographical lines on Figure 3 represent the elevations that occur in the survey area.

The survey area is underlain by three soil types: Metz loamy sand (zero to 2 percent slopes), Pits (zero to 5 percent slopes), and Riverwash (Figure 4, Soils). The northeastern corner of the survey area that cannot be characterized by soil type is water. Metz loamy sand occurs along the eastern edge of the survey area and consists of somewhat excessively drained soils that formed in alluvial material from mixed but dominantly sedimentary rocks, typically found in alluvial fans and floodplains. Pits constitutes a small portion in the northwestern corner of the survey area and consists of poorly drained soils that formed in fine-textured alluvium weathered from igneous rocks that are found on flood plains and in basins. Riverwash represents the majority of the survey area and consists of very recent depositions of gravel, sand, and silt alluvium along major streams and their tributaries (USDA 2019). The Riverwash and Pits soil types that occur in the survey area are classified as hydric (wetland) soils and have the potential to contain hydric inclusions (USDA 2019).

B.2 Hydrology
The project site is in the Santa Ana River Watershed (Hydrologic Unit 18070203) (USGS 2023).

The Santa Ana River Watershed is the largest in Southern California and encompasses 2,840 square miles within portions of Riverside and Orange Counties, and a small part of eastern Los Angeles County (USGS 2023). Santa Ana River Watershed supports a population of over 6 million people across these counties. The total length of the Santa Ana River and the streams that drain into it is approximately 700 miles, starting from its northernmost reaches at the crest of the San Bernardino Mountains out to the coast near Huntington Beach. This network of waterways includes features that are both natural and channelized in concrete. The Santa Ana River is defined by the USACE as a traditional navigable water (TNW) (USACE 2023a). Portions of the Santa Ana River are on the Clean Water Act Section 303(d) List for impaired waters, however, the reach in the survey area is not listed as impaired (SWRCB 2023).

The National Wetlands Inventory (NWI) results identify several mapped aquatic features in the survey area (Figure 5, National Wetlands Inventory Results) (USFWS 2021). The Santa Ana River is identified as a lake, as is also OCWD Basin 1 in the northwestern portion of the survey area. The OCWD Basin 2, west of the Santa Ana River and south of the OCWD Basin 1, is identified on the NWI results as both freshwater emergent wetland and freshwater pond. One riverine feature (Collin’s Channel) is identified connecting to the east side of the Santa Ana River in the central portion of the survey area. No other aquatic features are identified in the survey area by the NWI results.

Based on a review of the USGS National Hydrography Dataset (NHD), the survey area contains several mapped aquatic resources, including those that have hydrologic connections to the Santa Ana River (USGS 2023). The Santa Ana River is identified as a stream/river with an artificial path, likely because of the concrete channelization of the river and construction of the SAR1 Levee System Aquatic Resources Delineation Report 7 December 2023
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(Upstream Reach). Both OCWD Basins 1 and 2 are identified as reservoirs with intermittent connections to each other and the Santa Ana River. Collin’s Channel is identified as a canal/ditch that is connected to the Santa Ana River from the east. No other aquatic features are identified in the survey area by the USGS NHD results. The aquatic resources that occur in the survey area are discussed in Section E, Aquatic Resources Descriptions.

As previously discussed at the beginning of Section B, the aquatic resources and drainage patterns on and adjacent to the survey area are highly altered from urban development and stormwater control infrastructure, especially within the Santa Ana River corridor.

B.3 Vegetation Communities and Land Cover Types
A total of nine vegetation communities and land cover types were observed in the survey area: fresh water, emergent wetland, non-vegetated channel, Diegan coastal sage scrub, mulefat scrub (disturbed), southern willow scrub, non-native woodland, disturbed habitat, and developed land (Figure 6, Vegetation Communities and Land Cover Types). Four vegetation communities associated with aquatic resources in the survey area, fresh water, emergent wetland, non-vegetated channel, and southern willow scrub, are described in the following subsections. The aquatic resources associated with these vegetation communities are discussed further in Section E.

B.3.1 Fresh Water
Fresh water includes year-round bodies of fresh water in the form of lakes, streams, ponds, or rivers. Fresh water includes those portions of water bodies that are usually covered by water and contain less than 10 percent vegetated cover (Holland 1986).

A total of approximately 6.63 acres of fresh water was documented, with 3.48 acres occurring on the project site and the remaining 3.15 acres in the survey buffer (Figure 6). The fresh water in the survey area occurs within OCWD Basins 1 and 2, as well as the Islands Golf Center and the OCWD owned and operated water distribution plant in the northwestern portion of the survey area. OCWD Basins 1 and 2 have direct surface water connectivity to the Santa Ana River, directly east of the basins.

B.3.2 Emergent Wetland
Emergent wetlands are dominated by low growing, perennial wetland species. These can be found in channels, seeps and springs, floodplains, margins of lakes and rivers, and various basins such as pools and ponds, palustrine lakes, montane meadows, and dune swales. Characteristic species include sedges (Carex sp.), spikerushes (Eleocharis sp.), rushes (Juncus sp.), docks and sorrels (Rumex sp.), and giant bur-reed (Sparganium eurycarpum), and many others (Holland 1986).

A total of approximately 0.97 acre of emergent wetland was documented within OCWD Basin 2 in the western edge of the survey buffer, outside the project site (Figure 6). The emergent wetland within OCWD Basin 2 appears to receive water from OCWD Basin 1 through a large concrete box culvert Aquatic Resources Delineation Report 8 December 2023
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under Ball Road from the northwest. Saturated soils and surface water were observed in the emergent wetland during the May 2023 survey, and dominant plant species included curly dock (Rumex crispus), tall flatsedge (Cyperus eragrostis), Goodding’s willow (Salix gooddingii), mulefat (Baccharis salicifolia), and arundo (Arundo donax).

B.3.3 Non-Vegetated Channel
Non-vegetated channel consists of predominantly sandy, gravelly, or rocky channels lacking or with reduced vegetation. Variable water lines inhibit the growth of vegetation, although some weedy species of grasses may grow along the outer edges of the channel. Vegetation may exist there but is usually less than 10 percent of the total cover (Holland 1986).

Non-vegetated channel comprises the majority of the survey area. A total of approximately 76.28 acres of non-vegetated channel was documented, with 74.33 acres occurring on the project site and the remaining 1.95 acres in the survey buffer (Figure 6). The Santa Ana River and Collin’s Channel are both defined as non-vegetated channels. The extent of the Santa Ana River that runs northeast to southwest through the majority of the survey area is a fully concrete- and riprap-lined channel and does not support any vegetation. Collin’s Channel is a riprap- and concrete-lined channel that enters the eastern edge of the survey area and connects to the eastern side of the Santa Ana River.

Sparse grasses and weeds were observed growing through the rock riprap in Collin’s Channel, however, no substantial vegetation community was observed in the channel.

B.3.4 Southern Willow Scrub
Southern willow scrub consists of dense, broad-leaved, winter-deciduous stands of trees dominated by shrubby willows (Salix sp.) in association with mulefat. This vegetation community typically occurs on loose, sandy, or fine gravelly alluvium deposited near stream channels during flood flows (Holland 1986).

A total of approximately 1.63 acre of southern willow scrub was documented, with 0.66 acre occurring in the northwestern portion of the project site and 0.97 acre in the western edge of the survey buffer (Figure 6). The 0.66 acre of southern willow scrub on the project site is within and along the western shore of OCWD Basin 1. This area is dominated by Goodding’s willow, with mulefat and a small stand of bulrush (Typha sp.) in the understory. The 0.97 acre of southern willow scrub along the western edge of the survey buffer within OCWD Basin 2 is densely vegetated with Goodding’s willow with mulefat and black mustard (Brassica nigra) in the understory and outer edges.

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Section C Precipitation Data and Analysis
C.1 Climate and Growing Season
On a regional level, Orange County has a Mediterranean climate, which is characterized by wet winters and dry summers. This is largely because of a semi-permanent high-pressure zone that sits over the Pacific Ocean during much of the year and forms a fog belt (marine layer). Generalized climate in the region is regarded as dry, subhumid mesothermal, with warm dry summers and cold moist winters, which pushes the growing season to the wet months of the year (late winter to early spring). Annual vegetation often goes dormant (senescent) during the later summer months until initial rainfall starts in the fall. The rainy season typically lasts from late October through April.

The closest weather station to the survey area is Anaheim Lake, approximately 3 miles northeast of the survey area. Between 2003 and 2023, the average maximum temperature was 72 degrees Fahrenheit (°F), and the average minimum temperature was 52°F. The average annual precipitation during this time period was 13.2 inches. In 2022, the total rainfall was 6.35 inches, approximately

1.7 inches less than 2021 (NRCS 2023). As of May 2023, when the aquatic resources delineation fieldwork was conducted, total precipitation in the area was 19.4 inches, approximately 18 inches more than May 2022.

C.2 Antecedent Precipitation Tool and Natural Resources Conservation Service Wetlands Climate Table
Results Summary
A typical rainfall year in the City of Orange has historically been expressed by 13 inches of annual precipitation. To calculate if the aquatic resources delineation fell into a wet, dry, or typical rainfall year, the Antecedent Precipitation Tool, Version 2 (USACE 2023b) was used, and the National Integrated Drought Information System (NIDIS) was reviewed (NOAA 2023). The Antecedent Precipitation Tool and NIDIS results determined that the aquatic resources delineation was conducted in wetter than normal conditions for precipitation in the dry season during non-drought conditions (Attachment C, Antecedent Precipitation Tool and NRCS WETS Table Results).

Further, according to NIDIS for Orange County, May 2023 was the wettest May on record in the past 129 years, with the period of January to May 2023 receiving approximately 8.6 inches more precipitation than the average (NOAA 2023).

Attachment C includes the Natural Resources Conservation Service (NRCS) Wetland Climate Table for 2003–2023 at Anaheim Lake, California. Average annual precipitation in the area surrounding the survey area over the past 20 years was approximately 13.2 inches.

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C.3 Wetland Hydrology and Analysis
Historical and current aerial imagery, topographic maps, and NWI and USGS hydrology maps were reviewed to provide wetland hydrology and analysis. The NWI results are presented on Figure 5.

Both the NWI and USGS NHD maps identify the Santa Ana River, the OCWD Basins 1 and 2, and Collin’s Channel in the survey area (USFWS 2021; USGS 2023). No other aquatic features are identified in the survey area by the NWI or the USGS NHD results. Historical aerial imagery depicts what may have been the natural course of the Santa Ana River since at least 1952 and the subsequent channelization of the river between that time and 1963 when urban development increased in the surrounding area (Historic Aerials 2023). All aquatic resources observed in the survey area during the aquatic resources delineation fieldwork on May 16, 2023, are documented in the NWI and USGS NHD mapping results (Figure 5).

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Section D Methods
D.1 Pre-Field Review
Prior to conducting fieldwork, the following materials were reviewed:
• Topographic maps
• Aerial imagery (Google Earth 1985–2022)
• Historical aerial imagery (Historic Aerials 2023)
• U.S. Fish and Wildlife Service NWI Wetlands Mapper maps (USFWS 2021) • USGS NHD maps (USGS 2023)
• U.S. Department of Agriculture NRCS Web Soil Survey for the project site, which lists hydric soils found in Orange County (USDA 2019)
D.2 On-Site Aquatic Resources Delineation
The aquatic resources delineation was conducted using the routine on-site determination method described in the USACE Wetlands Delineation Manual (USACE 1987) and the Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Arid West Region (USACE 2008a). A Harris aquatic resources specialist conducted the aquatic resources delineation fieldwork on May 16, 2023, to identify aquatic resources on the project site and within a 100-foot survey buffer surrounding the project site (together referred to as the survey area). An Arid West Region Ordinary High Water Mark (OHWM) datasheet and a USACE three-parameter wetland determination datasheet for the Arid West Region (wetland determination datasheet) were completed at each sampling point (non-wetland sampling points NW-1-1, NW-1-2, NW-2-1, and NW-2-2; wetland sampling points W-1-1, W-1-2, W-2-1, and W-2-2) for each unique aquatic resource feature (Attachment D, Arid West Ordinary High Water Mark and Wetland Determination Datasheets). Each sampling point was collected to investigate the presence and extent of potential wetland and non-wetland waters.

Because the two non-wetland waters documented in the survey area, the Santa Ana River and Collin’s Channel, are completely channelized with concrete and riprap, the channel dimensions do not change and are uniform throughout their reaches within the survey area. Therefore, only one non-wetland sampling point was collected for each feature. The OCWD Basins 1 and 2 are on private property, and while direct access to these areas was not provided, binoculars were used to collect data to complete the wetland determination datasheets to the extent feasible. The representative photographs of the aquatic resources that occur in the survey area are provided in Attachment E, Photographic Log. The delineation methods applied at each sampling point are described below.

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Sampling point NW-1-1 was collected in the center of the Santa Ana River where the concrete-lined channel enters the northern portion of the survey area (Figure 7, Aquatic Resources; Photographs 1 through 3). Sampling point NW-1-1 documents where an OHWM was observed to determine the extent of the non-wetland feature. The delineation results for sampling point NW-1-1 are presented in Section E.

Sampling point NW-1-2 was collected in the center of the Santa Ana River at the southern end of the survey area to document the southern limits of the Santa Ana River in the survey area (Figure 7; Photograph 8). The delineation results for sampling point NW-1-2 are presented in Section E.

Sampling point NW-2-1 was collected in the center of Collin’s Channel where the riprap-lined channel enters the northeastern edge of the survey area (Figure 7; Photograph 9). Sampling point NW-2-1 documents where an OHWM was observed and was used to determine the extent of the non-wetland feature. The delineation results for sampling point NW-2-1 are presented in Section E.

Sampling point NW-2-2 was collected in the center of Collin’s Channel where the concrete-lined channel connects to the Santa Ana River through a concrete box culvert (Figure 7; Photograph 10). Sampling point NW-2-2 documents the southwestern limit of Collin’s Channel in the survey area. The delineation results for sampling point NW-2-2 are presented in Section E.

Sampling point W-1-1 was collected in the eastern portion of the OCWD Basin 1 approximately 1 foot below the observed OHWM (Figure 7; Photographs 12 and 16). A wetland determination datasheet was completed at sampling point W-1-1 to determine the presence of wetland indicators in this portion of the survey area. The delineation results for sampling point W-1-1 are presented in Section E.

Sampling point W-1-2 was collected in the eastern portion of the OCWD Basin 1 approximately 5 feet above the observed OHWM (Figure 7; Photograph 13). A wetland determination datasheet was completed at sampling point W-1-2 to determine the presence of wetland indicators in this portion of the survey area. The delineation results for sampling point W-1-2 are presented in Section E.

Sampling point W-2-1 was collected in the eastern portion of the OCWD Basin 2 approximately 1 foot below the observed OHWM (Figure 7; Photographs 18 and 19). A wetland determination datasheet was completed at sampling point W-2-1 to determine the presence of wetland indicators in this portion of the survey area. The delineation results for sampling point W-2-1 are presented in Section E.

Sampling point W-2-2 was collected in the eastern portion of the OCWD Basin 2 approximately 5 feet above the observed OHWM (Figure 7; Photographs 18 through 22). A wetland determination datasheet was completed at sampling point W-2-2 to determine the presence of wetland indicators in this portion of the survey area. The delineation results for sampling point W-2-2 are presented in Section E.

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D.3 On-Site Ordinary High Water Mark Investigation
The aquatic resources delineation was conducted using the routine on-site determination method described in A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States: A Delineation Manual (USACE 2008b). As described in Section B, the survey area consists of a primarily urban developed land in the eastern portion of the City of Orange, adjacent to the City of Anaheim.

Data on vegetation, soil, and hydrologic characteristics was collected and recorded following the guidance in A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States: A Delineation Manual (USACE 2008b). An OHWM datasheet was completed for locations of non-wetland waters in the survey area, the Santa Ana River and Collin’s Channel, (Attachment D). The OHWMs in the Santa Ana River (sampling point NW-1-1) and Collin’s Channel (sampling point NW-2-1) were identified based on field observations of presence of OHWM (USACE 2008b). Because both of these non-wetland waters are completely channelized in concrete and riprap, other defined non-wetland water indicators, including changes in sediment texture, vegetation species or cover, break in bank slope, and floodplain contours, were not present and could not be documented per the field guide. Results of the OHWM identifications conducted for sampling points NW-1-1 and NW-2-1 are in Section E.

D.4 Streamflow Duration Assessment
The Streamflow Duration Assessment Method (SDAM) for the Arid West was completed for Channels 1 and 2 (USEPA 2023) (Attachment F, SDAM for the Arid West Forms). SDAMs are rapid field assessment methods that use hydrological, geomorphological, and/or biological indicators, observable in a single site visit, to classify streamflow duration as perennial, intermittent, or ephemeral at the reach scale. The SDAM results for the Santa Ana River and Collin’s Channel are presented in Section E.

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Section E Aquatic Resources Descriptions
E.1 Non-Wetland Waters
The Santa Ana River, Collin’s Channel, and OCWD Basins 1 and 2 observed in the survey area were determined to be non-wetland waters. The non-wetland waters observed in the survey area are summarized in Table 1, Non-Wetland Waters in the Survey Area, and described in the following subsections.

Table 1. Non-Wetland Waters in the Survey Area
Feature Non-Wetland Waters (acres) Linear Feet
Santa Ana River 75.96 8,953
Collin’s Channel 0.32 248
OCWD Basin 1 6.63 —
OCWD Basin 1 Southern Willow Scrub 0.66 —
OCWD Basin 2 (Including Emergent
Wetland)

0.97 —
Total1 84.54 9,201
Notes:
1 Total rounded to one-hundredth of an acre.

The completed OHWM datasheets for the Santa Ana River and Collin’s Channel (sampling points NW-1-1, NW-1-2, NW-2-1, and NW-2-2) and the wetland datasheets for OCWD Basins 1 and 2 (sampling points W-1-1, W-1-2, W-2-1, and W-2-2) are in Attachment D. Representative photographs of the aquatic resources and sampling points taken in the survey area are in Attachment E. Electronic spatial data of the aquatic resources in the survey area is in Attachment F, Geographic Information Systems Data. The USACE ORM Bulk Upload Aquatic Resources Spreadsheet for the aquatic resources observed in the survey area is in Attachment G, ORM Bulk Upload Aquatic Resources Spreadsheet.

E.1.1 Santa Ana River
The Santa Ana River is a concrete- and riprap-lined channel that enters the northeastern portion of the survey area and extends approximately 8,953 linear feet south through the center of the survey area (Figure 7). The Santa Ana River exits the southern end of the survey area and continues south.

The entire length of the Santa Ana River within the survey area is defined by an OHWM with a width of approximately 315 feet. The SDAM conducted for the Santa Ana River determined that it is at least an intermittent feature, but likely perennial (Attachment F).

E.1.1.1 Ordinary High Water Mark Analysis
The Santa Ana River is an approximately 75.96-acre (8,953-linear-foot) non-wetland water that extends through the center of the majority of the survey area (Table 1; Figure 7). Figure 7 shows Aquatic Resources Delineation Report 16 December 2023
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where sampling points NW-1-1 and NW-1-2 were collected in the OHWM of the Santa Ana River to document the extent of this aquatic feature within the survey area. Photographs 1 through 8 in Attachment E provide representative views of the extent of the Santa Ana River in the survey area.

The OHWM indicators investigated at sampling points NW-1-1 and NW-1-2 are described below.

Sampling Point NW-1-1: The OHWM is approximately 315 feet wide and 1.5 feet deep. Other OHWM indicators observed at sampling point NW-1-1 include a break in bank slope and the presence of a defined bed and bank. The Santa Ana River is completely concrete lined with rock riprap lining the channel banks (Photographs 1 through 3). No vegetation or soils were observed within the limits of the Santa Ana River channel. At sampling point NW-1-1, the Santa Ana River is surrounded by developed land, with the OCWD Basins 1 and 2 approximately 460 feet northwest and 340 feet west, respectively. The Santa Ana River is significantly lower in elevation than the surrounding survey area.

Sampling Point NW-1-2: The OHWM is approximately 315 feet wide and 1.5 feet deep. Other OHWM indicators observed at sampling point NW-1-2 include a break in bank slope and the presence of a defined bed and bank. The Santa Ana River is completely concrete lined with rock riprap lining the channel banks (Photograph 8). No vegetation or soils were observed within the limits of the Santa Ana River channel. At sampling point NW-1-2, the Santa Ana River is surrounded by developed land, with the channelized river continuing to the south. The Santa Ana River is significantly lower in elevation than the surrounding survey area.

E.1.2 Collin’s Channel
Collin’s Channel is a riprap- and concrete-lined channel that enters the eastern edge of the survey area and connects to the eastern side of the Santa Ana River through a large box culvert (Figure 7; Photographs 9 through 11). The entire length of Collin’s Channel is defined by an OHWM with a width of approximately 5 feet. The SDAM conducted for Collin’s Channel determined that it is at least an intermittent feature (Attachment F).

E.1.2.1 Ordinary High Water Mark Analysis
Collin’s Channel is an approximately 0.32-acre (248-linear-foot) non-wetland water that occurs in the eastern portion of the survey area (Table 1; Figure 7). Figure 7 shows where sampling points NW-2-1 and NW-2-2 were collected in the OHWM of Collin’s Channel. Photographs 9 through 11 in Attachment E provide representative views of the extent of Collin’s Channel in the survey area. The OHWM indicators investigated at sampling points NW-2-1 and NW-2-2 are described below.

Sampling Point NW-2-1: The OHWM is approximately 5 feet wide and 0.5 foot deep. Other OHWM indicators observed at sampling point NW-2-1 include a break in bank slope and the presence of a defined bed and bank. Collin’s Channel is completely lined with rock riprap and no soils were Aquatic Resources Delineation Report 17 December 2023
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visible. Sparse grasses and weeds were observed growing through the rock riprap outside the OHWM at sampling point NW-2-1 (Photograph 9). At sampling point NW-2-1, Collin’s Channel is surrounded by developed land, with the Santa Ana River corridor directly to the west. Collin’s Channel is lower in elevation than the surrounding survey area loam.

Sampling Point NW-2-2: The OHWM is approximately 5 feet wide and 0.5 foot deep. Other OHWM indicators observed at sampling point NW-2-2 include a break in bank slope and the presence of a defined bed and bank. Collin’s Channel is completely concrete lined at sampling point NW-2-2 (Photograph 10). No vegetation or soils were observed within Collin’s Channel at sampling point NW-2-2. Collin’s Channel is surrounded by developed land, with the Santa Ana River corridor directly to the west. Collin’s Channel is lower in elevation than the surrounding survey area loam.

E.1.3 Orange County Water District Basin 1
OCWD Basin 1 occurs in the northwestern portion of the survey area (Figure 7; Photographs 12 through 17). This area is characterized as a large, depressed basin with a predominantly unvegetated slope that decreases in elevation until it reaches what appeared to be the OHWM of the basin. Ponded fresh water was observed within OCWD Basin 1 up to the OHWM. The majority of OCWD Basin 1 is unvegetated, however, the west−central edge of the basin is vegetated with a stand of southern willow scrub, including Goodding’s willow, mulefat, and bulrush (Typha sp.) which appear to be growing along and just under the OHWM. OCWD Basin 1 was determined to be a non-wetland water containing both non-wetland (fresh water) and an emergent wetland within the limits of the OHWM. OCWD Basin 1 has a minimum depth of 1 foot along the edges. The maximum depth of OCWD Basin 1 could not be determined because there was no direct access to the basin. OCWD Basin 1 is connected to OCWD Basin 2 through a concrete box culvert in the southwestern corner that runs under Ball Road.

E.1.3.1 Aquatic Resources Delineation Results
OCWD Basin 1 is an approximately 7.29-acre non-wetland water in the northwestern portion of the survey area (Table 1; Figure 7). As previously discussed in Section B, OCWD Basin 1 is a managed water detention basin owned and operated by the OCWD. The OHWM of the basin was documented based on observed indicators, including abrupt shifts in vegetative cover and water staining along the shoreline. Sampling points W-1-1 and W-1-2 described below were collected in the western portion of the basin to document the presence of wetland indicators (Figure 7).

Photographs 12 through 17 in Attachment E provide representative views of the extent of OCWD Basin 1 in the survey area. The completed wetland determination datasheets for sampling points W-1-1 and W-1-2 are in Attachment D. Wetland indicators investigated at sampling points W-1-2 and W-1-2 are described below.

Sampling Point W-1-1: Sampling point W-1-1 was collected approximately 1 foot below the observed OHWM in the western portion of OCWD Basin 1 (Figure 7; Photographs 12 and 16). The data Aquatic Resources Delineation Report 18 December 2023
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collected at sampling point W-1-1 determined that wetland hydrology, hydric soils, and hydrophytic vegetation were present or assumed to be present, based on specific factors.

Two facultative wetland plants, Goodding's willow and mulefat, and one upland plant, black mustard, were the dominant plant species at sampling point W-1-1. Therefore, hydrophytic vegetation was determined to be present. No soil pit could be dug at sampling point W-1-1 because there was no direct access to the basin. However, hydric soil was assumed present based on longterm inundation and saturation as well as the persistence of hydrophytic vegetation in the water detention basin (Historic Aerials 2023). The presence of surface water and soil saturation observed at sampling point W-1-1 determined that wetland hydrology is present. While all three wetland indicators were determined to be present, these indicators occur below the OHWM of OCWD Basin 1. Therefore, OCWD Basin 1 is considered a non-wetland water with a three-parameter emergent wetland within the limits of the feature.

Sampling Point W-1-2: Sampling point W-1-2 was collected approximately 5 feet above the observed OHWM in the western portion of OCWD Basin 1 (Figure 7; Photograph 13). The data collected at sampling point W-1-2 determined that wetland hydrology, hydric soils, and hydrophytic vegetation were not present. Two upland plant species, black mustard and star thistle (Centaurea calcitrapa), were documented at sampling point W-1-2. Therefore, hydrophytic vegetation was determined not to be present. No soil pit could be dug at sampling point W-1-2 because there was no direct access to the basin. However, hydric soils were assumed not to be present based on the location of the sampling point above the observed OHWM of the managed water detention basin and the lack of wetland plant species supported by the soil (Historic Aerials 2023). None of the three wetland indicators were observed at sampling point W-1-2, and this area was determined to be upland.

Sampling point W-1-2 functions as an upland sampling point paired with sampling point W-1-1, delineating the limits of the non-wetland water OCWD Basin 1 and the in-feature three-parameter wetland.

E.1.4 Orange County Water District Basin 2
The eastern half of OCWD Basin 2 occurs in the northwestern portion of the survey area, south of OCWD Basin 1 (Figure 7). This area is characterized as a large, depressed basin with a densely vegetated slope that decreases in elevation until it reaches the bottom of the basin, which is also densely vegetated with predominantly arundo, curly dock, and Goodding's willow. OCWD Basin 2 was determined to be a non-wetland water that contains an emergent wetland within the limits of the OHWM. OCWD Basin 2 is connected to OCWD Basin 1 to the north through a concrete box culvert that runs under Ball Road. A concrete box culvert in the southeastern corner of OCWD Basin 2 connects it to the Santa Ana River channel to the southeast.

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E.1.4.1 Aquatic Resources Delineation Results
OCWD Basin 2 is an approximately 1.94-acre non-wetland water in the northwestern portion of the survey area (Table 1; Figure 7). As previously discussed in Section B, OCWD Basin 2 is a managed water detention basin owned and operated by the OCWD. The OHWM of the basin was documented based on observed indicators, including abrupt shifts in vegetative species and cover and water staining along the shoreline. Sampling points W-2-1 and W-2-2 described below were collected in the eastern portion of the basin to document the presence of wetland indicators (Figure 7). The completed wetland determination datasheets for sampling points W-2-1 and W-2-2 are in Attachment D. Wetland indicators investigated at sampling points W-2-1 and W-2-2 are described below.

Sampling Point W-2-1: Sampling point W-2-1 was collected approximately 1 foot below the observed OHWM in the eastern portion of OCWD Basin 2. The data collected at sampling point W-2-1 determined that wetland hydrology, hydric soils, and hydrophytic vegetation were present (Figure 7; Photographs 18 and 19). Two facultative wetland plants, Goodding's willow and arundo, and one facultative plant, curly dock, were the dominant plant species at sampling point W-2-1.

Therefore, hydrophytic vegetation was determined to be present. No soil pit could be dug at sampling point W-2-1 because there was no direct access to the basin. However, hydric soil was assumed present based on long-term inundation and saturation as well as the presence of hydrophytic vegetation in the water detention basin (Historic Aerials 2023). The presence of surface water and soil saturation observed at sampling point W-2-1 determined that wetland hydrology is present. While all three wetland indicators were determined to be present, these indicators occur below the OHWM of OCWD Basin 2. Therefore, OCWD Basin 2 is considered a non-wetland water with a three-parameter emergent wetland within the limits of the feature.

Sampling Point W-2-2: Sampling point W-2-2 was collected approximately 5 feet above the observed OHWM in the eastern portion of OCWD Basin 2. The data collected at sampling point W-2-2 determined that wetland hydrology, hydric soils, and hydrophytic vegetation were not present (Figure 7; Photographs 18 through 22). The only plants that occur at sampling point W-2-2 are two upland plant species, black mustard and star thistle. Therefore, hydrophytic vegetation was determined not to be present. No soil pit could be dug at sampling point W-2-2 because there was no direct access to the basin. However, hydric soils were assumed not to be present based on the location of the sampling point above the observed OHWM of the managed water detention basin and the lack of wetland plant species supported by the soil (Historic Aerials 2023). None of the three wetland indicators were observed at sampling point W-2-2, and this area was determined to be upland. Sampling point W-2-2 functions as an upland sampling point paired with sampling point W-2-1, delineating the limits of the non-wetland water OCWD Basin 2.

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Section F Deviation from Local Wetlands Inventory or
National Wetlands Inventory
The NWI and USGS NHD mapping results identify all four of the aquatic resources observed in the survey area during the aquatic resources delineation fieldwork. No other aquatic resources were identified in the survey area by the NWI and USGS NHD results or observed during the aquatic resources delineation fieldwork.

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Section G Mapping Method
Limits of the wetland and non-wetland, non-tidal waters were digitally mapped at the OHWM and top of bank using an ISXBlue II sub-meter Global Positioning System (GPS) unit. Electronic spatial data collected in the field is in Attachment G.

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Section H Conclusions
Based on the investigation of wetland and non-wetland water indicators, the following four nonwetland waters and two in-feature emergent wetlands occur in the survey area:

1. One non-wetland water (Santa Ana River) was observed entering the northeastern portion of the survey area and continuing south through center of the majority of the survey area. The Santa Ana River is a non-vegetated concrete- and riprap-lined channel that accounts for approximately 75.96 acres (8,953 linear feet) of non-wetland water in the survey area. The Santa Ana River exits the southern end of the survey area and continues south. The SDAM conducted for the Santa Ana River determined that it is at least an intermittent feature, but likely perennial.

2. One non-wetland water (Collin’s Channel) was observed entering the eastern edge of the survey area and ending where it connects to the eastern side of the Santa Ana River through a large box culvert. Collin’s Channel is a riprap- and concrete-lined channel that accounts for approximately 0.32 acre (248 linear feet) of non-wetland water in the survey area. The SDAM conducted for Collin’s Channel determined that it is at least an intermittent feature.

3. One non-wetland (OCWD Basin 1) was observed in the northwestern survey area.

OCWD Basin 1 accounts for approximately 7.29 acres of non-wetland water, including approximately 6.63 acres of open water and 0.66 acre of southern willow scrub (infeature emergent wetland) in the survey area.

4. One non-wetland (OCWD Basin 2) was observed in the northwestern survey area.

OCWD Basin 2 accounts for approximately 1.94 acre of non-wetland water, including approximately 0.97 acre of emergent wetland and 0.97 acre of southern willow scrub (both in-feature emergent wetlands) in the survey area.

Summaries of the aquatic resources delineated in the survey area are provided in Table 2, Summary of Non-Wetland Waters in the Survey Area. Additional information can be provided upon request.

Table 2. Summary of Non-Wetland Waters in the Survey Area Feature
Cowardin
Type1 Acres
Linear
Feet Coordinates
Vegetation/
Land Cover
Type Summary
Santa
Ana
River
R2 75.96 8,953 33.816217 N, -
117.869850 W;

33.795948 N, -
117.879276 W
Non-vegetated
channel
Concrete- and riprap-lined non-wetland
water with OHWM indicators present.

The OHWM is approximately 315 feet
wide and 1.5 feet deep.

Collin’s
Channel
R6 0.32 248 33.804223 N, -
117.873957 W;

33.803637 N, -
117.875120 W
Non-vegetated
channel
Concrete- and riprap-lined non-wetland
water with OHWM indicators present.

The OHWM is approximately 5 feet
wide and 0.5 foot deep. Connected to
the Santa Ana River to the west.

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Table 2. Summary of Non-Wetland Waters in the Survey Area Feature
Cowardin
Type1 Acres
Linear
Feet Coordinates
Vegetation/
Land Cover
Type Summary
OCWD
Basin 1
L2OW/
RP2EM

7.29 — 32.819225 N,
−117.871173 W
Fresh water to
OHWM and
southern
willow scrub
Non-wetland water with OHWM
indicators present. Open water within
and up to the OHWM (includes 0.66
acre of southern willow scrub).

Connected to OCWD Basin 2 to the
south.

OCWD
Basin 2
L2UB/
RP2EM

1.94 — 32.815055 N,
−117.871481 W
Emergent
wetland and
southern
willow scrub
Non-wetland water with OHWM
indicators present. Includes 0.97 acre of
emergent wetland and 0.97 acre of
southern willow scrub up to the OHWM.

Connected to the Santa Ana River to
the southeast.

Non-Wetland Total2 83.88 9,201 —
Notes: OCWD = Orange County Water District; OHWM = ordinary high water mark 1 Cowardin Type: L2OW = Open water/unknown bottom, littoral, lacustrine; L2UB = Unconsolidated bottom, littoral, lacustrine; R2 = Lower perennial, riverine; R6 = A wetland, spring, stream, river, pond, or lake that only exists for a short period of time; RP2EM = Emergent, lentic riparian.
2 Total rounded to one-hundredth of an acre.

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Section I Preliminary Jurisdictional Determinations
The aquatic resources observed in the survey area include the Santa Ana River, Collin’s Channel, and OCWD Basins 1 and 2. Table 3, Potential Jurisdiction of Aquatic Resources in the Survey Area, provides a summary of the aquatic resources and potential jurisdiction of these features. It should be noted that only the resource agencies, USACE, Regional Water Quality Control Board (RWQCB), and/or California Department of Fish and Wildlife (CDFW), can make a final determination of jurisdictional boundaries.

The Santa Ana River is defined by the USACE as a TNW and has direct downstream connectivity to the Pacific Ocean (USACE 2023a). Therefore, the Santa Ana River is potentially under the jurisdiction of the USACE pursuant to the Clean Water Act, Section 404 (Figure 8, Potential Jurisdictional Waters of the U.S. for the OC River Walk Project). Further, the reach of the Santa Ana River in the survey area contains the SAR1 Levee System (Upstream Reach) and therefore is potentially under the jurisdiction of the USACE pursuant to the Rivers and Harbors Act Section 408. Although the Santa Ana River is completely channelized with concrete and riprap lining, it conveys natural flows as well as urban stormwater through the primarily developed Orange County, providing water quality and habitat functions for the Santa Ana River Watershed, and, therefore, is potentially under the jurisdiction of the RWQCB and CDFW, pursuant to the Clean Water Act, Section 401, and California Fish and Game Code, Section 1602, respectively (Figure 9, Potential Jurisdictional Waters of the State for the OC River Walk Project).

Collin’s Channel was determined to be an intermittent non-wetland water with direct connectivity to the to the nearest TNW, the Santa Ana River. Therefore, Collin’s Channel is potentially under the jurisdiction of the USACE pursuant to the Clean Water Act, Section 404 (Figure 8). Although Collin’s Channel is completely channelized with concrete and riprap lining, it conveys natural flows as well as urban stormwater through the primarily developed City of Orange, providing water quality functions for the Santa Ana River Watershed, and, therefore, is potentially under the jurisdiction of the RWQCB and CDFW, pursuant to the Clean Water Act, Section 401, and California Fish and Game Code, Section 1602, respectively (Figure 9).

OCWD Basins 1 and 2 were determined to be non-wetland waters that contain in-feature wetlands and are hydrologically connected to the nearest TNW, the Santa Ana River. Therefore, OCWD Basins 1 and 2 are potentially under the jurisdiction of the USACE pursuant to the Clean Water Act, Section 404 (Figure 8). Although OCWD Basins 1 and 2 are artificially maintained water detention facilities, these basins store fresh water and direct it into the Santa Ana River, providing water quality and habitat functions for the Santa Ana River Watershed, and, therefore, are potentially under the jurisdiction of the RWQCB and the CDFW, pursuant to the Clean Water Act, Section 401, and California Fish and Game Code, Section 1602, respectively (Figure 9).

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Table 3. Potential Jurisdiction of Aquatic Resources in the Survey Area Feature
Feature
Type
Vegetation/
Land Cover
Type
Cowardi
n Type1
Agency Jurisdiction
Description
USACE
404 408 RWQCB CDFW
Santa
Ana
River
Nonwetland
water
Nonvegetated
channel
R2 X X X X
Perennial concrete- and
riprap-lined channel that flows
north from to south through
the center of the survey area.

The Santa Ana River is
defined by the USACE as a
TNW and has direct
downstream connectivity to
the Pacific Ocean.

Collin’s
Channel
Nonwetland
water
Nonvegetated
channel
R6 X — X X
Intermittent concrete- and
riprap-lined channel that flows
from northeast to southwest in
the eastern portion of the
survey area. The channel
connects to the eastern side
of the Santa Ana River
through a large box culvert.

OCWD
Basin 1
Nonwetland
water
Fresh water
to OHWM
and willow
riparian
woodland L2OW/
RP2EM X — X X
Artificial water detention
basin, owned and operated by
the OCWD, in the northwest
portion of the survey area.

The basin connects to OCWD
Basin 2 through a concrete
box culvert in the
southwestern corner that runs
under Ball Road.

OCWD
Basin 2
Nonwetland
water
Freshwater
marsh and
willow
riparian
woodland
L2UB/
RP2EM X — X X
Artificial water detention
basin, owned and operated by
the OCWD, in the northwest
portion of the survey area.

The basin connects to the
Santa Ana River through a
concrete box culvert in the
southeastern corner.

Notes: 404 = Clean Water Act Section 404; 408 = Rivers and Harbors Act Section 408; CDFW = California Department of Fish and Wildlife; RWQCB = Regional Water Quality Control Board; TNW = traditional navigable water; USACE = U.S. Army Corps of Engineers
1 Cowardin Type: R2 = Lower perennial, riverine; R6 = A wetland, spring, stream, river, pond, or lake that only exists for a short period of time; L2OW = Open water/unknown bottom, littoral, lacustrine; L2UB = Unconsolidated bottom, littoral, lacustrine; RP2EM = Emergent, lentic riparian.

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Section J Disclaimer Statement
The aquatic resources delineation and preliminary jurisdictional determinations are subject to verification by the USACE, RWQCB, and CDFW. Harris advises all parties to treat the information in this Aquatic Resources Delineation Report as preliminary until the agencies provide written verification of their respective jurisdictional boundaries.

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Section K References
Google Earth. 2023. Accessed July 2023. https://earth.google.com/web/.

Historic Aerials. 2023. “Historic Aerials.” Accessed July 2023. https://www.historicaerials. com/location/32.706548675246815/-117.16177568660387/1988/16.

Holland, Robert F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities of California. California Department of Fish and Game. October. NOAA. 2023. National Integrated Drought Information System. Drought Conditions in Orange County. Accessed July 2023. https://www.drought.gov/states/california/county/Orange.

NRCS. 2023. National Water and Climate Center: WETS Table. Accessed July 2023. https://www.wcc.nrcs.usda.gov/climate/navigate_wets.html.

State Water Resources Control Board (SWRCB). 2023. 2018 California Integrated Report (Clean Water Act Section 303(d) List and 305(b) Report). Accessed July 2023. https://www.waterboards.ca.gov/water_issues/programs/water_quality_assessment/2018_inte grated_report.html.

USACE (U.S. Army Corps of Engineers). 1987. Corps of Engineers Wetlands Delineation Manual.

Final report. Wetlands Research Program Technical Report Y-87-1 (online edition). Prepared by Environmental Laboratory, U.S. Army Corps of Engineers, Waterways Experiment Station.

Wetlands Research Program. January. Accessed July 2023. http://www.cpe .rutgers.edu/Wetlands/1987-Army-Corps-Wetlands-Delineation-Manual.pdf.

USACE. 2008a. Regional Supplement to the Corps of Engineers Wetlands Delineation Manual: Arid West Region (Version 2.0). Final report. ERDC/EL TR-08-28. Prepared by Environmental Laboratory, U.S. Army Engineer Research and Development Center. Wetlands Regulatory Assistance Program. September. Accessed July 2023. https://usace.contentdm.oclc.org/ utils/getfile/collection/p266001coll1/id/7627.

USACE. 2008b. A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States: A Delineation Manual. ERDC/CRREL TR-08-12. Prepared by Robert W. Lichvar and Shawn M. McColley. Cold Regions Research and Engineering Laboratory, U.S. Army Engineer Research and Development Center. August.

Accessed July 2023. https://www.spl.usace.army.mil/Portals/17/docs/regulatory/JD/ FinalOHWMManual_2008.pdf.

USACE. 2015. Santa Ana River 1 Levee System. August 2015. Accessed July 2023. https://www.spl.usace.army.mil/Portals/17/docs/LeveeSafetyProgram/San_Ana_River_1_Le vee_System_PI_Report_No-01_ES_M_20151023.pdf.

USACE. 2023a. “TNWs & Navigable Waters in Los Angeles District.” Accessed July 2023. https://www.spl.usace.army.mil/Missions/Regulatory/Jurisdictional-Determination/Navigable -Waterways/.

USACE. 2023b. Antecedent Precipitation Tool. Accessed July 2023. https://github.com/j Deters-ACOE/Antecedent-Precipitation-Tool.

Aquatic Resources Delineation Report 32 July 2023
OC River Walk Project
USDA (U.S. Department of Agriculture). 2019. Web Soil Survey. Natural Resources Conservation Service, Soil Survey Staff. Last modified July 31. Accessed July 2023. http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm.

USEPA (U.S. Environmental Protection Agency). 2023. Beta Streamflow Duration Assessment Method for the Arid West (Beta SDAM AW). Version 1.0. March 1. Accessed December 2023. https://betasdamaw-sccwrp.hub.arcgis.com/.

USFWS (U.S. Fish and Wildlife Service). 2021. National Wetlands Inventory Wetlands Mapper. Last updated November 30. Accessed July 2023. https://www.fws.gov/wetlands/Data /Mapper.html.

USGS (U.S. Geological Survey). 2023. National Hydrography Data. Accessed July 2023. https://www.arcgis.com/home/webmap/viewer.html?url=https://hydro.nationalmap.gov/arcgi s/rest/services/nhd/MapServer&source=sd.

Attachment A. Figures
This page intentionally left blank.

Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure1_Regional.mxd Dana
Point
San Juan
Capistrano
Laguna
Beach
Laguna
Hills Coto De
Caza
Newport
Beach Mission
Viejo
Trabuco
Highlands
Costa
Mesa
Irvine
Huntington
Beach
Tustin
Seal
Beach
Garden
Grove
Orange
Anaheim
Placentia Yorba Linda
Fullerton
Corona
March
Woodcrest AFB
Norco
Riverside
Rubidoux
Wildomar
Lake
Elsinore
Carson
Long
Beach
Cerritos
Gardena Bellflower Compton
Downey
Diamond
Bar
Industry
Walnut
Alhambra Covina
Pomona
Claremont
Glendora
Irwindale
Burbank Monrovia
Altadena
Pasadena Glendale
Acton
Chino
Hills
Chino
Loma
Linda
Ontario Bloomington Colton
Upland Fontana Rialto
Crestline
Hesperia
Victorville
Cypress
nglewood
Whittier
Commerce
Montebello
Rosemead
Arcadia
Los Angeles County
Orange County
San Bernardino County
Los Angeles County
Riverside County
Orange County
Orange County
San Diego
County
P a c i f i c O c e a n
£¤101
£¤395
ÄÆ1
ÄÆ18
ÄÆ57
ÄÆ47
ÄÆ39
ÄÆ91
259 ÄÆ
ÄÆ60
ÄÆ57
ÄÆ91
103 ÄÆ
ÄÆ39
ÄÆ55
ÄÆ91
ÄÆ60
ÄÆ73
159 ÄÆ
ÄÆ39
241 ÄÆ
ÄÆ18
142 ÄÆ
206 ÄÆ
173 ÄÆ
134 ÄÆ
ÄÆ1
133 ÄÆ
ÄÆ2
ÄÆ71
ÄÆ60
ÄÆ22
ÄÆ72
ÄÆ90
ÄÆ83
ÄÆ14 ÄÆ18
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§¨¦210
§¨¦15
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§¨¦215
§¨¦105
§¨¦405
§¨¦210
§¨¦10
§¨¦15
OC River Walk Project
Incorporated Areas
Project Site
!(^
Regional Location
Source: ESRI 2020.

Figure 1 ± 0 5 10
Miles
Source: PACE Advanced Water Engineering 2024.

C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\1st Screencheck DEIR Figure 2
Local Vicinity
OC River Walk Project
Feet
N
0 600 1200
Project Site
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure3_USGS.mxd USGS Topographic Map
Source: USGS 7.5 Minute Anaheim and Orange Quadrangles 1974. ±
0 1,000 2,000 Figure 3
Feet
OC River Walk Project
ÄÆ57

HILDA ST

WINSTON RD

RILES CIR

POPLAR ST

BARKLEY AVE

PRIMROSE DR

DOUGLASS RD

SEQUOIA AVE

PHOENIX CLUB DR

SINCLAIR ST

OMEGA AVE

STRUCK AVE

CLIFPARK WAY

CARL ST
ELM ST

YALE AVE

TRENTON AVE

WALNUT AVE

DOUGLASS RD

ECKHOFF ST

ORANGEWOOD AVE

TAFT AVE

HOWELL AVE

COLLINS AVEMAIN ST

SUNKIST ST

CERRITOS AVE

GROVE AVE

BATAVIA ST

BALL RD

KATELLA AVE
Project Site
Soils
Metz Loamy Sand
Pits
Riverwash
Water
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure4_Soil.mxd Soils
Source: Eagle Imagery 2017.
± 0 500 1,000 Figure 4
Feet
OC River Walk Project
ÄÆ57ÄÆ57
§¨¦5
Project Site
Aquatic Resource Type
Freshwater Emergent Wetland
Freshwater Forested/Shrub Wetland
Freshwater Pond
Lake
Riverine
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure5_NWI.mxd Source: USFWS 2023; Maxar Imagery 2021.
±
0 1,000 2,000
Feet National Wetlands Inventory Results
Source: USFWS 2023; Maxar Imagery 2021.

Figure 5
OC River Walk Project
O CWD Ba si n 1
O CWD Ba si n 2
San t a A n a R iv er
Co l li n 's C h an n e l
ÄÆ57
Project Site
100-Foot Buffer
Vegetation Communities
and Land Cover Types
Developed
Diegan Coastal Sage Scrub
Disturbed Habitat
Mulefat Scrub (Disturbed)
Emergent Wetland
Non-Native Woodland
Non-Vegetated Channel
Fresh Water
Southern Willow Scrub
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure6_Vegetation.mxd Vegetation Communities and Land Cover Types
Source: Maxar Imagery 2021.
± 0 500 1,000 Figure 6
Feet
OC River Walk Project
See Inset Map See Inset Map
O CWD Ba si n 1
$+
$+
$+
$+ $+
$+
$+ $+
$+
!(
!(
!(
!(
!(
!(!(
!(
OC W D B a sin 1
OC W D B a sin 2
San ta A na R iv er
C olli n' s C ha nne l
NW-1-1
NW-2-1
W-2-1
NW-1-2
NW-2-2
W-1-1
W-1-2
W-2-2
ÄÆ57
Project Site
100-Foot Buffer
$+ Culverts
!( Sampling Points
Aquatic Resources
Emergent Wetland
Non-Wetland Waters
Date: 6/30/2023 - La st saved by: Randy.Deodat - Pa th: C:\GIS \P rojects\Ci ty of A naheim \O C River Wal k\Map Docs\B io\B TR\Fig ure7 _AquaticResources.mxd Aquatic Resources
Source: Maxar Imagery 2021.
± 0 500 1,000 Figure 7
Feet
OC River Walk Project
$+
$+
$+
$+
$+
$+
$+
$+
$+
!(
!(
!(
!(
!(
!(!(!(
!
!
San ta A na R iv er
C olli n' s C ha nne l
OC W D B a sin 1
OC W D B a sin 2

33.817 ,-117.868

33.806 ,-117.876
NW-1-1
NW-2-1
W-2-1
NW-1-2
NW-2-2
W-1-1
W-1-2
W-2-2
Created on June 8th, 2023
Revised on June 9th, 2023
Coordinate System: NAD 1983 California State Plane Zone 6 Projection: Lambert Conformal Conic
Datum: North American 1983
Vertical Datum: No Coordinate System
1 inch = 1,050 feet
Date: 6/30/2023 - La st saved by: Randy.Deodat - Pa th: C:\GIS \P rojects\Ci ty of A naheim \O C River Wal k\Map Docs\B io\A RD\Figure8_JD_OHWM .m xd ±
0 500 1,000
Feet
Legend
Project Site
100-Foot Survey Buffer
! Reference Points $+ Culverts !( Sampling Points
Aquatic Resources
Emergent Wetland
Non-Wetland Waters
Potential Jurisdictional Waters
of the U.S. for the
OC River Walk Project
Figure 8
Made in accordance with the Updated Map and Drawing Standards for the South Pacific Division Regulatory Program, as amended on February 10, 2016, by: Jason Deters, Project Manager Enforcement and Special Projects Unit U.S. Army Corps of Engineers South Pacific Division Sacramento District, Regulatory Division
1325 J Street, Room 1350
Sacramento, California 95814-2922
$+
$+
$+
$+
$+
$+
$+
$+
$+
!
!
!(
!(
!(
!(
!(
!(!(!( San ta A na R iv er
C olli n' s C ha nne l
OC W D B a sin 1
OC W D B a sin 2

33.817 ,-117.868

33.806 ,-117.876
NW-1-1
NW-2-1
W-2-1
NW-1-2
NW-2-2
W-1-1
W-1-2
W-2-2
Created on June 8th, 2023
Revised on June 9th, 2023
Coordinate System: NAD 1983 California State Plane Zone 6 Projection: Lambert Conformal Conic
Datum: North American 1983
Vertical Datum: No Coordinate System
1 inch = 1,050 feet
Date: 6/30/2023 - La st saved by: Randy.Deodat - Pa th: C:\GIS \P rojects\Ci ty of A naheim \O C River Wal k\Map Docs\B io\A RD\Figure9_JD_TOB .mxd ±
0 500 1,000
Feet
Legend
Project Site
100-Foot Survey Buffer
! Reference Points $+ Culverts !( Sampling Points
Aquatic Resources
Emergent Wetland
Non-Wetland Waters
Potential Jurisdictional Waters
of the State for the
OC River Walk Project
Figure 9
Made in accordance with the Updated Map and Drawing Standards for the South Pacific Division Regulatory Program, as amended on February 10, 2016, by: Jason Deters, Project Manager Enforcement and Special Projects Unit U.S. Army Corps of Engineers South Pacific Division Sacramento District, Regulatory Division
1325 J Street, Room 1350
Sacramento, California 95814-2922
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Attachment B. Statement of Access
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Aquatic Resources Delineation Report B-1 July 2023
OC River Walk Project
Statement of Access
The majority of the project site is publicly accessible on public roadways and the Santa Ana River Trail (see Section A.2, Project Site Access, in the Aquatic Resources Delineation Report), and therefore, U.S. Army Corps of Engineers personnel will not need permission from the property owners to access the project site.

Starting from Interstate 5 north, take Exit 107A toward Pomona onto State Route 57 north, and after 2 miles take Exit 3 for Ball Road, turn right, then turn left into the Islands Golf Center to access the northern portion of the project site. The remainder of the project site to the south includes the Santa Ana River corridor and can be accessed via the Santa Ana River Trail. The geographic coordinates for the northern and southern limits of the project site are approximately

33.821440°N, −117.870396°W, 33.795975°N, −117.878083°W, respectively.

Aquatic Resources Delineation Report B-2 July 2023
OC River Walk Project
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Attachment C. Antecedent Precipitation Tool and
NRCS WETS Table Results
This page intentionally left blank.

WETS Table

WETS Station: ANAHEIM,
CA
Requested years: 2003 -
2023
Month Avg Max
Temp
Avg Min
Temp
Avg Mean
Temp
Avg
Precip
30%
chance
precip less
than
30%
chance
precip
more than
Avg number
days precip

0.10 or more
Avg
Snowfall
Jan 71.7 49.4 60.5 3.13 0.62 3.28 4 -
Feb 71.7 49.4 60.6 2.37 0.86 2.74 4 -
Mar 74.4 51.9 63.1 1.67 0.52 1.89 3 -
Apr 76.8 54.5 65.7 0.79 0.17 0.71 2 -
May 78.0 58.3 68.2 0.84 0.28 0.81 1 -
Jun 82.1 62.1 72.1 0.04 0.00 0.02 0 -
Jul 87.7 66.2 77.0 0.15 0.00 0.10 0 -
Aug 89.0 66.5 77.8 0.01 0.00 0.00 0 -
Sep 88.5 64.8 76.7 0.21 0.00 0.19 0 -
Oct - - - - - - - -
Nov 77.2 53.6 65.4 0.95 0.26 0.92 2 -
Dec 69.8 48.6 59.2 2.84 1.18 3.46 4 -
Annual: - -
Average - - - - - - - -
Total - - - - - -

GROWING SEASON DATES
Years with missing data: 24 deg = 1 28 deg = 1 32 deg = 1 Years with no occurrence: 24 deg = 20 28 deg = 20 32 deg = 20 Data years used: 24 deg = 20 28 deg = 20 32 deg = 20
Probability 24 F or
higher
28 F or
higher
32 F or
higher
50 percent * No
occurrence
No
occurrence
No
occurrence
70 percent * No
occurrence
No
occurrence
No
occurrence
* Percent chance of the
growing season occurring
between the Beginning and
Ending dates.

STATS TABLE - total
precipitation (inches)
Yr Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annl 1989     0.00 0.
49 0.
42 0.46 T 1.37
1990 2.33 3.85 0.15 0.75 0.64 0.02 0.00 0.00 0.
00 0.
00 0.28 0.
02 8.04
1991 1.75 3.15 5.36 0.00 0.00 0.00 0.03 0.00 0.
01 0.
32 0.02 1.
32 11.
96 1992 1.45 6.49 4.75 0.21 0.00 0.00 0.26 0.00 0.
00 0.
93 0.00 5.
88 19.
97 1993 9.17 4.33 2.23 0.00 0.00 1.23 0.00 0.00 0.
00 0.
05 0.99 0.
86 18.
86 1994 0.51 2.61 1.92 1.14 0.23 0.00 0.00 0.00 0.
00 0.
10 0.93 0.
71 8.15
1995 10.49 1.39 5.94 0.55 0.24 1.21 0.03 0.00 0.
00 0.
00 0.00 1.
02 20.
87 1996 1.96 4.47 2.37 0.64 0.00 0.00 0.00 0.00 0.
00 1.
14 3.18 3.
63 17.
39 1997 4.84 0.24 0.00 0.00 0.00 0.05 T 0.00 0.
47 0.
00 2.48 3.
42 11.
50 1998 2.65 11.54 2.82 1.07 2.68 0.05 0.00 T 0.
10 0.
00 1.17 0.
82 22.
90 1999 1.38 0.14 1.29 1.44 0.00 0.10 0.10 0.00 0.
00 0.
00 0.34 0.
07 4.86
2000 0.96 4.50 1.10 1.79 0.00 0.00 T 0.00 0.
12 1.
71 0.00 0.
02 10.
20 2001 2.26 4.62 0.59 0.69 0.00 0.02 0.00 0.00 0.
00 0.
00 1.12 1.
45 10.
75 2002 0.34 0.15 0.31 0.22 0.23 0.00 0.00 0.00 0.
00 0.
08 1.91 2.
54 5.78
2003 0.04 3.99 3.27 1.96 0.72 0.01 0.15 0.00 0.
00 0.
00 0.62 1.
11 11.
87 2004 0.29 5.26 0.61 0.93 0.00 0.00 0.00 0.00 0.
00 6.
85 1.17 3.
19 18.
30 2005 8.18 8.66 1.24 1.11 0.24 0.01 M0.00 0.00 0.
33 M0.
80 0.08 0.
80 21.
45 2006 1.00 1.78 M0.63 2.00 1.12 0.02 0.08 0.11 0.
00 0.
07 0.00 0.
68 7.49
2007 0.12 1.20 0.00 0.36 0.00 0.00 0.00 M0.00 0.
26 0.
40 0.00 1.
02 3.36
2008 4.45 1.25 0.04 0.00 1.15 0.00 0.00 0.00 0.
00 0.
00 1.62 3.
05 11.
56 2009 M0.68 M2.02 M0.12 0.00 0.00 0.05 0.28 0.00 0.
00 0.
58 0.00 4.
65 8.38
2010 17.75 3.94 0.18 0.98 0.00 0.14 0.00 0.00 0.
00 2.
27 5.86 10.
11 41.
23 2011 M0.57 2.10 2.67 M0.02 M4.44 0.38 M0.05 0.00 0.
54 M1.
00 M0.
46 0.
06 12.
29 2012 1.08 0.72 2.16 M3.20 M3.01 0.00 0.57 0.00 0.
02 0.
04 1.13 4.
50 16.
43 2013 M1.08 0.62 M1.25 0.00 0.39 0.00 0.04 0.00 0.
08 0.
25 0.46 0.
59 4.76
2014 0.00 1.95 0.71 1.02 2.00 0.00 1.09 0.07 0.
50 0.
00 1.01 4.
38 12.
73 2015 1.31 2.21 0.60 0.42 1.10 0.01 0.78 0.00 1.
77 1.
03 0.05 1.
13 10.
41 2016 2.84 0.52 1.02 0.20 0.08 0.09 0.00 0.00 0.
00 1.
07 1.06 6.
35 13.
23 2017 10.02 3.01 0.08 0.04 0.40 0.00 0.00 0.00 0.
23 0.
00 0.05 0.
50 14.
33 2018 1.36 0.46 2.07 0.01 0.05 0.00 0.00 0.00 0.
00 0.
66 1.33 2.
26 8.20
2019 6.10 6.10 4.36 1.67 0.96 0.00 0.00 0.00 0.
00 0.
00 2.06 4.
10 25.
35 2020 0.30 0.06 3.41 2.28 0.28 0.01 0.00 0.00 0.
05 0.
00 0.10 1.
46 7.95
2021 1.65 0.00 1.25 0.00 0.00 0.00 0.00 0.00 0.
22 0.
42 0.00 4.
50 8.04
2022 0.08 0.13 0.94 0.23 0.00 0.00 0.02 0.00 0.
29 0.
22 1.99 2.
45 6.35
2023 6.82 3.52 7.41 0.07 1.61 M0.00           19.
43 Notes: Data missing in any
month have an "M" flag. A
"T" indicates a trace of
precipitation.

Data missing for all days in
a month or year is blank.

Creation date: 2023-06-05
Attachment D. Arid West Ordinary High Water Mark Datasheets This page intentionally left blank.

Arid West Ephemeral and Intermittent Streams OHWM Datasheet Project: Date: Time:

Project Number: Town: State:

Stream: Photo begin file#: Photo end file#:

Investigator(s):

Y / N Do normal circumstances exist on the site?
Y / N Is the site significantly disturbed?
Location Details:

Projection: Datum:

Coordinates:

Potential anthropogenic influences on the channel system:

Brief site description:

Checklist of resources (if available):

Aerial photography
Dates:

Topographic maps
Geologic maps
Vegetation maps
Soils maps
Rainfall/precipitation maps
Existing delineation(s) for site
Global positioning system (GPS)
Other studies
Stream gage data
Gage number:

Period of record:

History of recent effective discharges
Results of flood frequency analysis
Most recent shift-adjusted rating
Gage heights for 2-, 5-, 10-, and 25-year events and the most recent event exceeding a 5-year event
Procedure for identifying and characterizing the floodplain units to assist in identifying the OHWM:

1. Walk the channel and floodplain within the study area to get an impression of the geomorphology and vegetation present at the site.

2. Select a representative cross section across the channel. Draw the cross section and label the floodplain units.

3. Determine a point on the cross section that is characteristic of one of the hydrogeomorphic floodplain units. a) Record the floodplain unit and GPS position.
b) Describe the sediment texture (using the Wentworth class size) and the vegetation characteristics of the floodplain unit.
c) Identify any indicators present at the location.

4. Repeat for other points in different hydrogeomorphic floodplain units across the cross section.

5. Identify the OHWM and record the indicators. Record the OHWM position via:

Mapping on aerial photograph GPS
Digitized on computer Other:

Project ID: Cross section ID: Date: Time:

Cross section drawing:

OHWM
GPS point: ___________________________
Indicators:

Change in average sediment texture Break in bank slope
Change in vegetation species Other: ____________________ Change in vegetation cover Other: ____________________
Comments:

Floodplain unit: Low-Flow Channel Active Floodplain Low Terrace GPS point: ___________________________
Characteristics of the floodplain unit:

Average sediment texture: __________________
Total veg cover: _____ % Tree: _____% Shrub: _____% Herb: _____% Community successional stage:

NA Mid (herbaceous, shrubs, saplings)
Early (herbaceous & seedlings) Late (herbaceous, shrubs, mature trees) Indicators:

Mudcracks Soil development
Ripples Surface relief
Drift and/or debris Other: ____________________
Presence of bed and bank Other: ____________________
Benches Other: ____________________
Comments:

Project ID: Cross section ID: Date: Time:

Cross section drawing:

OHWM
GPS point: ___________________________
Indicators:

Change in average sediment texture Break in bank slope
Change in vegetation species Other: ____________________ Change in vegetation cover Other: ____________________
Comments:

Floodplain unit: Low-Flow Channel Active Floodplain Low Terrace GPS point: ___________________________
Characteristics of the floodplain unit:

Average sediment texture: __________________
Total veg cover: _____ % Tree: _____% Shrub: _____% Herb: _____% Community successional stage:

NA Mid (herbaceous, shrubs, saplings)
Early (herbaceous & seedlings) Late (herbaceous, shrubs, mature trees) Indicators:

Mudcracks Soil development
Ripples Surface relief
Drift and/or debris Other: ____________________
Presence of bed and bank Other: ____________________
Benches Other: ____________________
Comments:

Arid West Ephemeral and Intermittent Streams OHWM Datasheet Project: Date: Time:

Project Number: Town: State:

Stream: Photo begin file#: Photo end file#:

Investigator(s):

Y / N Do normal circumstances exist on the site?
Y / N Is the site significantly disturbed?
Location Details:

Projection: Datum:

Coordinates:

Potential anthropogenic influences on the channel system:

Brief site description:

Checklist of resources (if available):

Aerial photography
Dates:

Topographic maps
Geologic maps
Vegetation maps
Soils maps
Rainfall/precipitation maps
Existing delineation(s) for site
Global positioning system (GPS)
Other studies
Stream gage data
Gage number:

Period of record:

History of recent effective discharges
Results of flood frequency analysis
Most recent shift-adjusted rating
Gage heights for 2-, 5-, 10-, and 25-year events and the most recent event exceeding a 5-year event
Procedure for identifying and characterizing the floodplain units to assist in identifying the OHWM:

1. Walk the channel and floodplain within the study area to get an impression of the geomorphology and vegetation present at the site.

2. Select a representative cross section across the channel. Draw the cross section and label the floodplain units.

3. Determine a point on the cross section that is characteristic of one of the hydrogeomorphic floodplain units. a) Record the floodplain unit and GPS position.
b) Describe the sediment texture (using the Wentworth class size) and the vegetation characteristics of the floodplain unit.
c) Identify any indicators present at the location.

4. Repeat for other points in different hydrogeomorphic floodplain units across the cross section.

5. Identify the OHWM and record the indicators. Record the OHWM position via:

Mapping on aerial photograph GPS
Digitized on computer Other:

Project ID: Cross section ID: Date: Time:

Cross section drawing:

OHWM
GPS point: ___________________________
Indicators:

Change in average sediment texture Break in bank slope
Change in vegetation species Other: ____________________ Change in vegetation cover Other: ____________________
Comments:

Floodplain unit: Low-Flow Channel Active Floodplain Low Terrace GPS point: ___________________________
Characteristics of the floodplain unit:

Average sediment texture: __________________
Total veg cover: _____ % Tree: _____% Shrub: _____% Herb: _____% Community successional stage:

NA Mid (herbaceous, shrubs, saplings)
Early (herbaceous & seedlings) Late (herbaceous, shrubs, mature trees) Indicators:

Mudcracks Soil development
Ripples Surface relief
Drift and/or debris Other: ____________________
Presence of bed and bank Other: ____________________
Benches Other: ____________________
Comments:

Project ID: Cross section ID: Date: Time:

Cross section drawing:

OHWM
GPS point: ___________________________
Indicators:

Change in average sediment texture Break in bank slope
Change in vegetation species Other: ____________________ Change in vegetation cover Other: ____________________
Comments:

Floodplain unit: Low-Flow Channel Active Floodplain Low Terrace GPS point: ___________________________
Characteristics of the floodplain unit:

Average sediment texture: __________________
Total veg cover: _____ % Tree: _____% Shrub: _____% Herb: _____% Community successional stage:

NA Mid (herbaceous, shrubs, saplings)
Early (herbaceous & seedlings) Late (herbaceous, shrubs, mature trees) Indicators:

Mudcracks Soil development
Ripples Surface relief
Drift and/or debris Other: ____________________
Presence of bed and bank Other: ____________________
Benches Other: ____________________
Comments:

US Army Corps of Engineers Arid West – Version 2.0
WETLAND DETERMINATION DATA FORM – Arid West Region
Project/Site: City/County: Sampling Date:

Applicant/Owner: State: Sampling Point:

Investigator(s): Section, Township, Range:

Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):

Subregion (LRR): Lat: Long: Datum:

Soil Map Unit Name: NWI classification:

Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , or Hydrology significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:

VEGETATION – Use scientific names of plants.

Dominance Test worksheet:

Number of Dominant Species
That Are OBL, FACW, or FAC: (A)
Total Number of Dominant
Species Across All Strata: (B)
Percent of Dominant Species
That Are OBL, FACW, or FAC: (A/B)
Prevalence Index worksheet:

Total % Cover of: Multiply by:

OBL species x 1 =
FACW species x 2 =
FAC species x 3 =
FACU species x 4 =
UPL species x 5 =
Column Totals: (A) (B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:

Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1
(Provide supporting
data in Remarks or on a separate sheet)
Problematic Hydrophytic Vegetation1
(Explain)
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.

Absolute Dominant Indicator
Tree Stratum (Plot size: ) % Cover Species? Status

1. 2.

3. 4.
= Total Cover
Sapling/Shrub Stratum (Plot size: )

1. 2.

3. 4.

5. = Total Cover
Herb Stratum (Plot size: )

1. 2.

3. 4.

5. 6.

7. 8.
= Total Cover
Woody Vine Stratum (Plot size: )

1. 2.
= Total Cover
% Bare Ground in Herb Stratum % Cover of Biotic Crust
Hydrophytic
Vegetation
Present? Yes No
Remarks:

US Army Corps of Engineers Arid West – Version 2.0
SOIL Sampling Point:

Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1
Loc2 Texture Remarks

1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.

Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:

Histosol (A1) Sandy Redox (S5) 1 cm Muck (A9) (LRR C)
Histic Epipedon (A2) Stripped Matrix (S6) 2 cm Muck (A10) (LRR B) Black Histic (A3) Loamy Mucky Mineral (F1) Reduced Vertic (F18) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Red Parent Material (TF2) Stratified Layers (A5) (LRR C) Depleted Matrix (F3) Other (Explain in Remarks) 1 cm Muck (A9) (LRR D) Redox Dark Surface (F6)
Depleted Below Dark Surface (A11) Depleted Dark Surface (F7) Thick Dark Surface (A12) Redox Depressions (F8) 3
Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Vernal Pools (F9) wetland hydrology must be present, Sandy Gleyed Matrix (S4) unless disturbed or problematic.

Restrictive Layer (if present):

Type:

Depth (inches): Hydric Soil Present? Yes No
Remarks:

HYDROLOGY
Wetland Hydrology Indicators:

Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Salt Crust (B11) Water Marks (B1) (Riverine) High Water Table (A2) Biotic Crust (B12) Sediment Deposits (B2) (Riverine) Saturation (A3) Aquatic Invertebrates (B13) Drift Deposits (B3) (Riverine) Water Marks (B1) (Nonriverine) Hydrogen Sulfide Odor (C1) Drainage Patterns (B10) Sediment Deposits (B2) (Nonriverine) Oxidized Rhizospheres along Living Roots (C3) Dry-Season Water Table (C2) Drift Deposits (B3) (Nonriverine) Presence of Reduced Iron (C4) Crayfish Burrows (C8) Surface Soil Cracks (B6) Recent Iron Reduction in Tilled Soils (C6) Saturation Visible on Aerial Imagery (C9) Inundation Visible on Aerial Imagery (B7) Thin Muck Surface (C7) Shallow Aquitard (D3) Water-Stained Leaves (B9) Other (Explain in Remarks) FAC-Neutral Test (D5) Field Observations:

Surface Water Present? Yes No Depth (inches):

Water Table Present? Yes No Depth (inches):

Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:

Remarks:

US Army Corps of Engineers Arid West – Version 2.0
WETLAND DETERMINATION DATA FORM – Arid West Region
Project/Site: City/County: Sampling Date:

Applicant/Owner: State: Sampling Point:

Investigator(s): Section, Township, Range:

Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):

Subregion (LRR): Lat: Long: Datum:

Soil Map Unit Name: NWI classification:

Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , or Hydrology significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:

VEGETATION – Use scientific names of plants.

Dominance Test worksheet:

Number of Dominant Species
That Are OBL, FACW, or FAC: (A)
Total Number of Dominant
Species Across All Strata: (B)
Percent of Dominant Species
That Are OBL, FACW, or FAC: (A/B)
Prevalence Index worksheet:

Total % Cover of: Multiply by:

OBL species x 1 =
FACW species x 2 =
FAC species x 3 =
FACU species x 4 =
UPL species x 5 =
Column Totals: (A) (B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:

Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1
(Provide supporting
data in Remarks or on a separate sheet)
Problematic Hydrophytic Vegetation1
(Explain)
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.

Absolute Dominant Indicator
Tree Stratum (Plot size: ) % Cover Species? Status

1. 2.

3. 4.
= Total Cover
Sapling/Shrub Stratum (Plot size: )

1. 2.

3. 4.

5. = Total Cover
Herb Stratum (Plot size: )

1. 2.

3. 4.

5. 6.

7. 8.
= Total Cover
Woody Vine Stratum (Plot size: )

1. 2.
= Total Cover
% Bare Ground in Herb Stratum % Cover of Biotic Crust
Hydrophytic
Vegetation
Present? Yes No
Remarks:

US Army Corps of Engineers Arid West – Version 2.0
SOIL Sampling Point:

Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1
Loc2 Texture Remarks

1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.

Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:

Histosol (A1) Sandy Redox (S5) 1 cm Muck (A9) (LRR C)
Histic Epipedon (A2) Stripped Matrix (S6) 2 cm Muck (A10) (LRR B) Black Histic (A3) Loamy Mucky Mineral (F1) Reduced Vertic (F18) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Red Parent Material (TF2) Stratified Layers (A5) (LRR C) Depleted Matrix (F3) Other (Explain in Remarks) 1 cm Muck (A9) (LRR D) Redox Dark Surface (F6)
Depleted Below Dark Surface (A11) Depleted Dark Surface (F7) Thick Dark Surface (A12) Redox Depressions (F8) 3
Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Vernal Pools (F9) wetland hydrology must be present, Sandy Gleyed Matrix (S4) unless disturbed or problematic.

Restrictive Layer (if present):

Type:

Depth (inches): Hydric Soil Present? Yes No
Remarks:

HYDROLOGY
Wetland Hydrology Indicators:

Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Salt Crust (B11) Water Marks (B1) (Riverine) High Water Table (A2) Biotic Crust (B12) Sediment Deposits (B2) (Riverine) Saturation (A3) Aquatic Invertebrates (B13) Drift Deposits (B3) (Riverine) Water Marks (B1) (Nonriverine) Hydrogen Sulfide Odor (C1) Drainage Patterns (B10) Sediment Deposits (B2) (Nonriverine) Oxidized Rhizospheres along Living Roots (C3) Dry-Season Water Table (C2) Drift Deposits (B3) (Nonriverine) Presence of Reduced Iron (C4) Crayfish Burrows (C8) Surface Soil Cracks (B6) Recent Iron Reduction in Tilled Soils (C6) Saturation Visible on Aerial Imagery (C9) Inundation Visible on Aerial Imagery (B7) Thin Muck Surface (C7) Shallow Aquitard (D3) Water-Stained Leaves (B9) Other (Explain in Remarks) FAC-Neutral Test (D5) Field Observations:

Surface Water Present? Yes No Depth (inches):

Water Table Present? Yes No Depth (inches):

Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:

Remarks:

US Army Corps of Engineers Arid West – Version 2.0
WETLAND DETERMINATION DATA FORM – Arid West Region
Project/Site: City/County: Sampling Date:

Applicant/Owner: State: Sampling Point:

Investigator(s): Section, Township, Range:

Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):

Subregion (LRR): Lat: Long: Datum:

Soil Map Unit Name: NWI classification:

Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , or Hydrology significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:

VEGETATION – Use scientific names of plants.

Dominance Test worksheet:

Number of Dominant Species
That Are OBL, FACW, or FAC: (A)
Total Number of Dominant
Species Across All Strata: (B)
Percent of Dominant Species
That Are OBL, FACW, or FAC: (A/B)
Prevalence Index worksheet:

Total % Cover of: Multiply by:

OBL species x 1 =
FACW species x 2 =
FAC species x 3 =
FACU species x 4 =
UPL species x 5 =
Column Totals: (A) (B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:

Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1
(Provide supporting
data in Remarks or on a separate sheet)
Problematic Hydrophytic Vegetation1
(Explain)
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.

Absolute Dominant Indicator
Tree Stratum (Plot size: ) % Cover Species? Status

1. 2.

3. 4.
= Total Cover
Sapling/Shrub Stratum (Plot size: )

1. 2.

3. 4.

5. = Total Cover
Herb Stratum (Plot size: )

1. 2.

3. 4.

5. 6.

7. 8.
= Total Cover
Woody Vine Stratum (Plot size: )

1. 2.
= Total Cover
% Bare Ground in Herb Stratum % Cover of Biotic Crust
Hydrophytic
Vegetation
Present? Yes No
Remarks:

US Army Corps of Engineers Arid West – Version 2.0
SOIL Sampling Point:

Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1
Loc2 Texture Remarks

1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.

Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:

Histosol (A1) Sandy Redox (S5) 1 cm Muck (A9) (LRR C)
Histic Epipedon (A2) Stripped Matrix (S6) 2 cm Muck (A10) (LRR B) Black Histic (A3) Loamy Mucky Mineral (F1) Reduced Vertic (F18) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Red Parent Material (TF2) Stratified Layers (A5) (LRR C) Depleted Matrix (F3) Other (Explain in Remarks) 1 cm Muck (A9) (LRR D) Redox Dark Surface (F6)
Depleted Below Dark Surface (A11) Depleted Dark Surface (F7) Thick Dark Surface (A12) Redox Depressions (F8) 3
Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Vernal Pools (F9) wetland hydrology must be present, Sandy Gleyed Matrix (S4) unless disturbed or problematic.

Restrictive Layer (if present):

Type:

Depth (inches): Hydric Soil Present? Yes No
Remarks:

HYDROLOGY
Wetland Hydrology Indicators:

Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Salt Crust (B11) Water Marks (B1) (Riverine) High Water Table (A2) Biotic Crust (B12) Sediment Deposits (B2) (Riverine) Saturation (A3) Aquatic Invertebrates (B13) Drift Deposits (B3) (Riverine) Water Marks (B1) (Nonriverine) Hydrogen Sulfide Odor (C1) Drainage Patterns (B10) Sediment Deposits (B2) (Nonriverine) Oxidized Rhizospheres along Living Roots (C3) Dry-Season Water Table (C2) Drift Deposits (B3) (Nonriverine) Presence of Reduced Iron (C4) Crayfish Burrows (C8) Surface Soil Cracks (B6) Recent Iron Reduction in Tilled Soils (C6) Saturation Visible on Aerial Imagery (C9) Inundation Visible on Aerial Imagery (B7) Thin Muck Surface (C7) Shallow Aquitard (D3) Water-Stained Leaves (B9) Other (Explain in Remarks) FAC-Neutral Test (D5) Field Observations:

Surface Water Present? Yes No Depth (inches):

Water Table Present? Yes No Depth (inches):

Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:

Remarks:

US Army Corps of Engineers Arid West – Version 2.0
WETLAND DETERMINATION DATA FORM – Arid West Region
Project/Site: City/County: Sampling Date:

Applicant/Owner: State: Sampling Point:

Investigator(s): Section, Township, Range:

Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):

Subregion (LRR): Lat: Long: Datum:

Soil Map Unit Name: NWI classification:

Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , or Hydrology significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.

Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:

VEGETATION – Use scientific names of plants.

Dominance Test worksheet:

Number of Dominant Species
That Are OBL, FACW, or FAC: (A)
Total Number of Dominant
Species Across All Strata: (B)
Percent of Dominant Species
That Are OBL, FACW, or FAC: (A/B)
Prevalence Index worksheet:

Total % Cover of: Multiply by:

OBL species x 1 =
FACW species x 2 =
FAC species x 3 =
FACU species x 4 =
UPL species x 5 =
Column Totals: (A) (B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:

Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1
(Provide supporting
data in Remarks or on a separate sheet)
Problematic Hydrophytic Vegetation1
(Explain)
1 Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.

Absolute Dominant Indicator
Tree Stratum (Plot size: ) % Cover Species? Status

1. 2.

3. 4.
= Total Cover
Sapling/Shrub Stratum (Plot size: )

1. 2.

3. 4.

5. = Total Cover
Herb Stratum (Plot size: )

1. 2.

3. 4.

5. 6.

7. 8.
= Total Cover
Woody Vine Stratum (Plot size: )

1. 2.
= Total Cover
% Bare Ground in Herb Stratum % Cover of Biotic Crust
Hydrophytic
Vegetation
Present? Yes No
Remarks:

US Army Corps of Engineers Arid West – Version 2.0
SOIL Sampling Point:

Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1
Loc2 Texture Remarks

1 Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.

Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:

Histosol (A1) Sandy Redox (S5) 1 cm Muck (A9) (LRR C)
Histic Epipedon (A2) Stripped Matrix (S6) 2 cm Muck (A10) (LRR B) Black Histic (A3) Loamy Mucky Mineral (F1) Reduced Vertic (F18) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Red Parent Material (TF2) Stratified Layers (A5) (LRR C) Depleted Matrix (F3) Other (Explain in Remarks) 1 cm Muck (A9) (LRR D) Redox Dark Surface (F6)
Depleted Below Dark Surface (A11) Depleted Dark Surface (F7) Thick Dark Surface (A12) Redox Depressions (F8) 3
Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Vernal Pools (F9) wetland hydrology must be present, Sandy Gleyed Matrix (S4) unless disturbed or problematic.

Restrictive Layer (if present):

Type:

Depth (inches): Hydric Soil Present? Yes No
Remarks:

HYDROLOGY
Wetland Hydrology Indicators:

Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Salt Crust (B11) Water Marks (B1) (Riverine) High Water Table (A2) Biotic Crust (B12) Sediment Deposits (B2) (Riverine) Saturation (A3) Aquatic Invertebrates (B13) Drift Deposits (B3) (Riverine) Water Marks (B1) (Nonriverine) Hydrogen Sulfide Odor (C1) Drainage Patterns (B10) Sediment Deposits (B2) (Nonriverine) Oxidized Rhizospheres along Living Roots (C3) Dry-Season Water Table (C2) Drift Deposits (B3) (Nonriverine) Presence of Reduced Iron (C4) Crayfish Burrows (C8) Surface Soil Cracks (B6) Recent Iron Reduction in Tilled Soils (C6) Saturation Visible on Aerial Imagery (C9) Inundation Visible on Aerial Imagery (B7) Thin Muck Surface (C7) Shallow Aquitard (D3) Water-Stained Leaves (B9) Other (Explain in Remarks) FAC-Neutral Test (D5) Field Observations:

Surface Water Present? Yes No Depth (inches):

Water Table Present? Yes No Depth (inches):

Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:

Remarks:

Attachment E. Photographic Log
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$+
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&!( !(& (!& !(&
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!(& !(&&!(
!(& !(&
!(&
(!&(!&
O C WD B a s i n 1
O C WD B a s i n 2 S a n ta A n a R iv e r
C o l l i n ' s C h a n n e l
8-240°
7-240°
11-220°
9-90°
10-210°
6-220°
22-270°
21-240°
18-330° 19-330°
20-240° 5-230°
3-340°
4-230°
1-40° 2-140°
AF-1-1
NW-2-1
W-2-1
NW-1-2
NW-2-2
W-1-1
W-1-2
W-2-2
Project Site
100-Foot Buffer
$+ Culverts !(& Photo Locations !( Sampling Points
Aquatic Resources
Emergent Wetland
Non-Wetland Waters
Open Water
Date: 6/12/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\ARD\AttachmentE_PhotoLog.mxd Photographic Log
Source: Maxar Imagery 2021.
±
0 500 1,000 Attachment E
Feet
OC River Walk
Aquatic Resources Delineation Report E-2 July 2023
OC River Walk Project
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Aquatic Resources Delineation Report E-3 July 2023
OC River Walk Project
Santa Ana River
Photograph 1: (Location: 33.817237 N, −117.870209 W) Northeast-facing view of the northern extent of the Santa Ana River where the concrete- and riprap-lined channel enters the northeastern portion of the survey area. This photograph shows the concrete-lined channel and riprap-lined banks of the river. Surface water is also visible in the bottom of the river channel.

Photograph 2: Location: 33.817237 N, −117.870209 W) Southeast-facing view of the northern extent of the Santa Ana River in the survey area. This photograph shows the flowing water through the center of the concrete- and riprap-lined channel. Also shown in the right-hand side background of the photograph is the consolidated deposited sediments in the center of the channel.

Aquatic Resources Delineation Report E-4 July 2023
OC River Walk Project
Photograph 3: (Location: 33.815586 N, −117.869401 W) Northwest-facing view of the Santa Ana River in the northwestern portion of the survey area where sampling point NW-1-1 was collected. Flowing water and deposited soils in the bottom of the channel are visible in the center of the photograph.

Photograph 4: (Location: 33.815586 N, −117.869401 W) Southwest-facing view of the Santa Ana River downstream of where sampling point NW-1-1 was collected. A concrete spillway and riprap that occur across the center of the concrete-lined channel are visible in the center of the photograph.

Aquatic Resources Delineation Report E-5 July 2023
OC River Walk Project
Photograph 5: (Location: 33.815202 N, −117.869595 W) Southwest-facing view of the Santa Ana River south of a spillway in the northern portion of the survey area. This photograph shows the heavy equipment being used to move deposited sediment in the bottom of the concrete- and riprap-lined channel.

Photograph 6: (Location: 33.805756 N, −117.874260 W) Southwest-facing view of the Santa Ana River in the south−central portion of the survey area. Surface water and deposited saturated soils are visible in the bottom of the concrete- and ripraplined channel.

Aquatic Resources Delineation Report E-6 July 2023
OC River Walk Project
Photograph 7: (Location: 33.802343 N, −117.875882 W) Southwest-facing view of the Santa Ana River in the south−central portion of the survey area. One of the many railroad bridges that cross the river corridor is shown in the background of the photograph.

Photograph 8: (Location: 33.795948 N, −117.879276 W) Southwest-facing view of the Santa Ana River in the southern portion of the survey area. This photograph shows where sampling point NW-1-2 was collected to document the presence of OHWM indicators. The concrete- and riprap-lined river channel continues south of the southern end of the survey area, shown in the background of the photograph. Also visible in this photograph is where the surface water in the bottom of the river channel ends, potentially due to buildup of sediment south of the bridge.

Aquatic Resources Delineation Report E-7 July 2023
OC River Walk Project
Collin’s Channel
Photograph 9: (Location: 33.803901 N, −117.874955 W) Northeast-facing view of Collin’s Channel showing where sampling point NW-2-1 was collected to document the presence of OHWM indicators. This photograph shows the riprap and concrete lining the channel. The sparse weeds and grasses growing through the riprap and surface water in the center of the channel are also shown in the center and background of the photograph.

Photograph 10: (Location: 33.803901 N, −117.874955 W) Southwest-facing view of Collin’s Channel showing where sampling point NW-2-2 was collected to document the presence of OHWM indicators. This photograph shows the concretelined channel, surface water flowing through the center, and the box culvert through which Collin’s Channel connects to the Santa Ana River channel.

Aquatic Resources Delineation Report E-8 July 2023
OC River Walk Project
Photograph 11: (Location: 33.803491 N, −117.875346 W) This photograph shows where Collin’s Channel connects to the Santa Ana River channel through a concrete box culvert. The surface water flowing from Collin’s Channel into the Santa Ana River channel is shown in the center of the photograph.

Orange County Water District (OCWD) Basin 1
Photograph 12: (Location: 33.819516 N, −117.871226 W) Southeast-facing view of OCWD Basin 1 where sampling point W-1-1 was collected to determine the presence of wetland and OHWM indicators. This photograph shows the ponded surface water of the basin in the background. The riparian woodland fringe at and below the observed OHWM, dominated by Goodding’s willow (Salix gooddingii) and mulefat (Baccharis salicifolia), surrounding sampling point W-1-1 is visible in the foreground.

Aquatic Resources Delineation Report E-9 July 2023
OC River Walk Project
Photograph 13: (Location: 33.819516 N, −117.871226 W) Northeast-facing view of OCWD Basin 1 where sampling point W-1-2 was collected on the western shoreline to determine the presence of wetland and OHWM indicators. The two dominant upland plant species, black mustard (Brassica nigra) and star thistle (Centaurea calcitrapa), are visible growing around the sampling point in the foreground of the photograph. The ponded surface water of the basin and riparian woodland fringe at and below the observed OHWM are visible in the background of the photograph.

Photograph 14: (Location: 33.818153 N, −117.871780 W) Northeast-facing view of the western shore and central portion of OCWD Basin 1. The disturbed habitat and disturbed mulefat scrub on the basin shoreline and upland are visible in the foreground of the photograph. The ponded surface water of the basin is visible in the background of the photograph. Also visible in the left-hand background of the photograph is the riparian woodland fringe at and below the observed OHWM of the basin.

Aquatic Resources Delineation Report E-10 July 2023
OC River Walk Project
Photograph 15: (Location: 33.818153 N, −117.871780 W) Southeast-facing view of the western shore and southern portion of OCWD Basin 1. The disturbed habitat and disturbed mulefat scrub on the basin shoreline and upland are visible in the foreground of the photograph. The ponded surface water of the basin is visible in the background of the photograph. Also visible in the background of the photograph is the heavy equipment being used to move deposited sediments in the Santa Ana River channel.

Photograph 16: (Location: 33.818138N, −117.869903 W) Southwest-facing view of the eastern shore and center of OCWD Basin 1 in the northwestern survey area. The disturbed shoreline and ponded surface water of the basin are visible in the foreground of the photograph. Also visible in the center-background of the photograph is the riparian woodland fringe at and below the observed OHWM of the basin where wetland sampling point W-1-1 was collected.

Aquatic Resources Delineation Report E-11 July 2023
OC River Walk Project
Photograph 17: (Location: 33.818138N, −117.869903 W) Northwest-facing view of the eastern shore and center of OCWD Basin 1 in the northwestern survey area. The OCWD pump house northwest of the survey area and OCWD Basin 1 are visible in the left-hand background of this photograph.

OCWD Basin 2
Photograph 18: (Location: 33.815653 N, −117.870881 W) Northwest-facing view of the northern end of OCWD Basin 2, south of OCWD Basin 1 in the northwestern portion of the survey area. This photograph shows where sampling point W-2-1 was collected to document the presence of wetland indicators. The densely vegetated emergent wetland, dominated by Goodding's willow (Salix gooddingii), arundo (Arundo donax), and curly dock (Rumex crispus), at and below the OHWM of the basin is visible in the center and background of the photograph. Sampling point W-2-2 is shown in the foreground and was collected to document the presence of wetland indicators. The disturbed habitat in the upland surrounding sampling point W-2-2 is shown in the foreground of the photograph.

Aquatic Resources Delineation Report E-12 July 2023
OC River Walk Project
Photograph 19: (Location: 33.815653 N, −117.870881 W) Northwest-facing view of the center of OCWD Basin 2, south of where sampling points W-2-1 and W-2-2 were collected. The emergent wetland and southern willow scrub in the center of the basin and the disturbed upland outside of the OHWM of the basin are visible in this photograph. Not visible in the background of the photograph, due to dense riparian vegetation, is the concrete box culvert connecting OCWD Basin 1 to OCWD Basin 2.

Photograph 20: (Location: 33.813611 N, −117.871835 W) Southwest-facing view of the center of OCWD Basin 2. The emergent wetland in the center of the basin and the disturbed upland outside the OHWM of the basin are visible in this photograph.

Aquatic Resources Delineation Report E-13 July 2023
OC River Walk Project
Photograph 21: (Location: 33.813611 N, −117.871835 W) Southwest-facing view of the southern portion of OCWD Basin 2. The southern end of the emergent wetland, dominated by curly dock (Rumex crispus) and tall flats edge (Cyperus eragrostis), is visible in the center of the photograph. A topographic rise (likely a pile of deposited sediment) in the southern end of the basin is also visible in the left-hand background of the photograph.

Photograph 22: (Location: 33.812913 N, −117.871977 W) West-facing view of southern end of OCWD Basin 2. The background of the photograph shows a concrete spillway in the basin with the disturbed habitat (primarily bare ground) to the east of the structure. The left-hand foreground of the photograph shows the entrance to a concrete box culvert connecting OCWD Basin 2 to the Santa Ana River channel.

Aquatic Resources Delineation Report E-14 July 2023
OC River Walk Project
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Attachment F. Geographic Information Systems Data
Available Upon Request.

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Attachment G. ORM Bulk Upload Aquatic Resources Spreadsheet This page intentionally left blank.

Waters_Name State Cowardin_Code HGM_Code Meas_Type Amount Units Waters_Type Latitude Longitude Local_Waterway Similarly_Situated Sim_Situated_Aggregated_SPOE Adjcent_Waters_Sbjct_33USC1344 OHWM_Chg_In_Plant_Community OHWM_Bed_And_Banks OHWM_Break_In_Slope OHWM_Chg_In_Character_Of_Soil OHWM_Chg_In_Veg_Densty_Maturty OHWM_Chg_In_Sediment_Texture OHWM_Line_Impressed_On_Bank OHWM_Destr_Of_Terrestrial_Veg OHWM_Leaf_Litter_Disturbed OHWM_Multiple_Flow_Events OHWM_Scour OHWM_Sediment_Deposition OHWM_Sediment_Sorting OHWM_Shelving OHWM_Litter_and_Debris_Present OHWM_Wrack_Line_Present OHWM_Veg_Matted_Bent_Or_Absent OHWM_Water_Staining OHWM_Other OHWM_Other_Text Func_I_Sediment_Trapping Func_II_Nutrient_Recycling Func_III_Pollutant_Management Func_IV_Retntn_Attenu_Fld_Wtrs Func_V_Runoff_Storage Func_VI_Contribution_of_Flow Func_VII_Export_Organic_Matter Func_VIII_Export_Food_Rsources Func_IX_Prov_Life_Cycle_Depdnt Santa Ana River California R2 RIVERINE Area 75.96 ACRE A1 33.816217 N 117.869850 W Santa Ana River NO NO NO NO YES YES NO NO NO NO NO NO NO NO NO NO NO NO NO NO YES NO YES NO NO YES YES YES NO NO NOCollin's Channel California R6 RIVERINE Area 0.32 ACRE A5 33.804223 N 117.873957 W Santa Ana River NO NO NO NO YES YES NO NO NO NO NO NO NO NO NO NO NO NO NO NO YES NO NO NO NO NO NO YES NO NO NOOCWD Basin 1* California L2OW LACUSTRINF Area 6.63 ACRE A4 32.819225 N 117.871173 W Santa Ana River NO NO NO NO YES YES NO NO NO YES NO NO NO NO NO NO NO NO NO NO YES NO YES NO NO YES YES YES NO NO NOOCWD Basin 2** California L2UB LACUSTRINF Area 0.97 ACRE A4 32.815055 N 117.871481 W Santa Ana River NO NO NO NO YES YES NO NO NO YES NO NO NO NO NO NO NO NO NO NO YES NO YES NO NO YES YES YES NO NO NO*In-feature wetland CALIFORNIA RP2EM LACUSTRINF Area 0.66 ACRE A4 33.819225 N 117.871173 W Santa Ana River NO NO NO NO YES YES NO NO NO YES NO NO NO NO NO NO NO NO NO NO YES NO YES NO NO YES YES NO NO NO NO**In-feature wetland CALIFORNIA RP2EM LACUSTRINF Area 0.97 ACRE A4 33.815055 N 117.871481 W Santa Ana River NO NO NO NO YES YES NO NO NO YES NO NO NO NO NO NO NO NO NO NO YES NO YES NO NO YES YES NO NO NO NO This page intentionally left blank.

Appendix E. Cultural Memo
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101 Progress, Suite 250, Irvine, CA 92618  p: 949.655.3900  f: 866.785.0180  WeAreHarris.com March 21, 2025
City of Anaheim
Community Service Department, Park Division
200 S. Anaheim Boulevard, Suite 433
Anaheim, California 92805
Contact: Ana Straabe, Principal Project Planner
Project: Orange County River Walk Project; Cultural Resources Survey Letter Report – Negative Findings Ms. Straabe:

Please be advised that a survey has been conducted by Harris & Associates on the above referenced project. It has been determined that cultural resources are not present on the subject properties. The project is plotted on the attached U.S. Geological Survey (USGS) 7.5-minute topographic map for your information.

County: Orange
USGS 7.5’ Quad: Anaheim, Orange; Date: 1974
Section: 13, 18, 19, 24, 25, 30; Township: 10S; Range: 09W, 10W; Land Grant: None City: Anaheim and Orange; State: California
Locational Data: Santa Ana River Corridor between Orangewood Avenue and Ball Road Bridge Crossings, Anaheim and Orange, CA
Assessor Parcel Number(s): 232-072-07, -08; 253-451-02, -03, -04, -07; 253-472-01; 253-521-36; 253-631-39; 374- 721-08; 374-791-01, -02, -03; 374-792-01, -02, -08, -10, -12; 375-221-01, -02, -03, -09, -10, -16, -17, -18, -19, -20, -21, -26; 375-301-01, -14, -15, -16; 375-311-13, -14, -15, -24, -27; 375-361-22; 386-521-02, -18 UTMs: 11S 419061mN, 3741958mE
Survey Type: Intensive Pedestrian/Phase I
Date of Survey: July 30, 2024
Field Crew: Jasmine Alvarez-Ceja
Setting
Project Description, Location, and Setting
The project site is located within a portion of the Santa Ana River between the Ball Road and Orangewood Avenue bridge crossings, is a 450-foot wide by 9,000-foot-long area (approx. 90 acres and 1.7 miles), and extends to the existing Anaheim Coves. It is adjacent to Angel Stadium, Anaheim Regional Transportation Intermodal Center, and the Honda Center. The project site is located within the Cities of Orange and Anaheim (Cities) with different landowners and jurisdictional bodies. (Attachment 1, Figures; Figure 1, Regional Location, Figure 2, Project Site, and Figure 3, USGS Topographic Map)
The majority of the project site includes the Santa Ana River corridor surrounded by urban development, including commercial, industrial, and residential uses. The northern portion of the project site includes the Orange County Water District (OCWD) pump house, associated water detention basins, and the eastern portion of the Islands Golf Center. Refer to Attachment 2, Photographs, for photographic documentation of the existing condition of the project site.
■ Harris & Associates
2 The OC River Walk Conceptual Master Plan consists of various multi-purpose improvements to transform the Santa Ana River corridor and portions of the existing Santa Ana River Trail (SART), along with related off-site improvements necessary for its implementation. The main components of the Conceptual Master Plan involve creating two water impoundments by installing three inflatable rubber dams, modifying the riverbanks, constructing two pedestrian/bike bridges, providing new trails, improving existing trails, creating new and protection of existing access ramps, constructing two new undercrossings on the west bank at the Union Pacific Railroad and the Metrolink railroad, providing enhanced community amenities (e.g., terraced seating, nature play areas, parklets, plazas, gathering areas for large-scale events, festivals, and other activities, water access, kayak launch, etc.), and other improvements. These improvements would require the implementation of 19 project elements, which have been categorized into four groups: Group A – Impoundments, Storm Drain Diversions, and Embankments; Group B – New Pedestrian/Bike Bridges; Group C – New Trails and Trail Improvements; and Group D – Enhanced Community Amenities. THistorical topographic maps and historical aerials were reviewed to understand the development of the project area of potential effect (APE) and surrounding properties. Historical aerials were reviewed from 1946 through 2020 (NETR Online 2024). Prior to 1955, the Santa Ana River was channelized and by 1977 the access roads are paved. The surrounding areas were in agricultural use in 1946 and by the early 1970s residential and commercial uses are present. By the 1990s the area was fully developed.

The cultural investigation described in this letter report was implemented to support the City’s responsibilities under the California Environmental Quality Act (CEQA) to incur no significant impacts to cultural resources resulting from the project.

Cultural Setting
The following cultural setting is taken in part from the City of Anaheim and City of Orange General Plan Environmental Impact Reports (EIR) (City of Anaheim 2004, City of Orange 2010a).

Prehistoric Setting
The generally accepted framework recognizes four broad temporal periods or cultural horizons. These are the Paleo-coastal or Early Man period dated to more than 10,000 years ago; the Millingstone Period, falling between 10,000 years ago and 3,000 years ago; the Intermediate Period from 3,000 years to 1,350 years ago, and the Late Prehistoric from 1,350 to 650 years ago.

Early Man/Initial Occupation
Initial occupation is thought to have occurred between 8,500 and 11,000 years ago (6,500 – 9,000 B.C.) in Southern California. One recent radiocarbon date from Santa Rosa Island suggests human occupation as early as 11,500 years ago and future research may prove even earlier occupation. Early occupants were viewed as mobile foragers primarily dependent on hunting terrestrial game. This period is characterized by the presence of large projectile points and scrapers, which is an indicator of a reliance on hunting. However, recent archaeological evidence from some coastal sites indicates the systematic and intensive use of marine resources, including shellfish, during this period.

Millingstone Period
Sites dating from around 8,000 years before present (6,000 B.C.) are far more common than those from the Initial Occupation period. They typically include groundstone assemblages, indicating a probable dependence on hard seeds. At coastal sites, there is continued evidence of a wide variety of marine resource exploitation, most commonly shellfish. Some archaeologists believed that terrestrial game still provided the foundation of the diet.

Some archaeologists note that the abundance of Millingstone Horizon sites suggests a sedentary settlement system, rather than a mobile foraging pattern, with central settlements and a logistically based economy supplied from special purpose camps and task sites. Sites of this time period typically yield large numbers of metates and manos, as well as unique artifacts of unknown use, called cogged stones or discoidals.

Intermediate Period
B I Harris & Associates
3 This period, from 1,000 B.C. to A.D. 750, reflects the transitional period between the Milling Stone and Late Prehistoric Horizons. At the beginning of this period important changes began to occur in settlement, technology and subsistence intensification caused by a growing population. Changes included the increased use of acorns, elaborate fishing technology, such as the introduction of the shell fishhook, and a diverse amount of hunting tools.

The apparent disuse of the Newport Coast area during this period is thought to have indicated the arrival of Shoshonean-speaking groups from the deserts to the east. Archaeologists believe these people were protoGabrieleno and Luiseño who were not yet familiar with marine resources.

Late Prehistoric Period
The Late Prehistoric Period, beginning approximately 1,350 years B.P. (650 A.D.), reflects high population densities and complex political, social, technological, and religious systems throughout the Los Angeles Basin. Economic systems, primarily based around the growing marine fisheries, became more diverse and intensive. The growing geographic complexity of trade networks is reflected in shell-bead currency and a variety of materials traded or acquired from remote locations. Technological improvements are seen in the appearance of the bow and arrow, the plank canoe in coastal sites, and a broad variety of marine resources including mammals and fish taken in deep sea environments. Settlements became permanent towns supported by temporary camps set up at resource procurement sites. Archaeological evidence of this time period includes the presence of projectile points, soapstone bowls, callus shell beads, steatite effigies and cremations. This period ended abruptly when Spanish colonists began establishing missions along the California coast.

Ethnographic Setting
The project is situated within the ethnographic territory of the Gabrielino Indians of California. Gabrielino lands included most of present-day Los Angeles and Orange counties, and several offshore islands. The Gabrielino spoke a Cupan language in the Takic family, which in turn is a member of the Ut o-Aztecan linguistic stock. The Gabrielino people lived in either permanent or semi-permanent villages. Known settlement locations seem to have favored two different locales; coastal estuaries and major inland watercourses. Villages are thought to have been the focus of family life, with each individual group linked to others by paternal kinship relations. Coastal Gabrielino exploited bay and kelpbed fish, shellfish, and occasionally sea mammals. Inland groups collected and processed plants and hunted deer, bear, quail and other terrestrial game.

Gabrielino culture was heavily affected by colonial Spanish missionary efforts long before systematic ethnographic studies could be conducted. Disease and forced participation in the mission system disrupted most traditional cultural lifeways and resulted in a catastrophic reduction of the native population. Information about their material culture and life ways is very limited and derived largely from historical sources, such as the diaries and records of early missionaries, soldiers and explorers. While traveling through the area in 1769, Father Crespi noted the presence of a large village, Hotuuknga, upstream from present day Olive on the north side of the Santa Ana River. Crespi wrote that 52 Indians came to greet them and accepted blankets, beads and other goods. When he returned two years later the group was hostile and the Spaniards quickly continued on their way. A small “Indian camp” was visible on the north side of Santiago Creek just west of the Glassell Street crossing as late as the 1870s.

What little ethnographic information is available suggests that the Late Prehistoric Gabrielino settlement pattern may have been characterized by a complex of central villages occupied by patrilineally constructed family lineages and smaller special purpose sites where specific resources were extracted or where food or other resources were collected for transportation back to central villages. Such a pattern is consistent with the "collector" economic model for complex hunter-gatherer societies such as the Gabrielino.

Historic Period
The earliest known records of European contact with Southern California Native Americans date to the mid-1500s, representing the early explorations of the Spanish. These explorations included the identification of populations from ships, but did not include direct contact. Personal contact was not made until the 1770s, when Father Garces traversed the Mojave Desert and entered coastal Southern California through the Cajon Pass.

B I Harris & Associates
4 In 1771, the Mission San Gabriel Archangel was founded. It soon became one of the richest missions controlling all of the property in Orange County north of Aliso Creek and a large portion of Los Angeles County. The Gabrielino Indians are named after the mission.

In the late 18th Century, Felipe de Neve, Spanish Governor of California, saw the opportunity to establish a pueblo along the River Los Angeles north of the San Gabriel Mission. The primary purpose of the pueblo was to reaffirm Spain’s claim over the territory in the face of encroachments by Russia in the north and Britain from the sea. The pueblo would also help to keep Spain’s California military garrisons supplied and fed.

In August 1781, Governor de Neve, the settlers (11 men, 11 women, and 22 children), soldiers, mission priests, and a few Native Americans arrived at the new pueblo alongside the Los Angeles River. Governor de Neve recorded the date of September 4, 1781, as the official date of establishment of El Pueblo de la Reina de Los Angeles.

Americans first arrived in Los Angeles by way of nearby San Pedro, then an unimproved port. Beginning in 1805, U.S. vessels kept up an intermittent trade with the area’s farmers, and in 1818 a crewmember, Joseph Chapman, helped construct the town’s first church. In 1826, Jedidiah Smith, a fur trapper, became the first white man to reach Los Angeles by traveling overland from the Missouri frontier.

Los Angeles was little affected by the revolution that replaced Spanish rule with that of an independent Mexican government in 1821. Mexico’s Congress declared Los Angeles the capital of California in 1835, but the provincial governor refused to move south from San Francisco. Therefore, the City’s relative isolation and the local authority of farmers and ranchers remained unthreatened. By the 1840s, Los Angeles had become the largest settlement in Southern California.

Methods, Regulatory Setting, Analysis of Project Effects, and Recommendations
The project includes the development of recreational, pedestrian, and bikeway improvements to the Santa Ana River corridor. This letter report provides an environmental baseline of the cultural resources present, an analysis of resources that have the potential to be present, and an analysis of impacts on cultural resources from project construction activities. The analysis was prepared in accordance with requirements of CEQA. Literature reviews and an intensive pedestrian cultural survey were conducted in July 2024 in support of this letter report.

Prior Research
Staff conducted a records search of the surrounding area using the California Historic Resources Inventory System (CHRIS) (Confidential Attachment 3, CHRIS Background Data). Data reviewed included identified reports and resources, historic maps, the National Register of Historic Places, California Register of Historical Resources, and Built Environment Resources Directory.

Thirty-seven studies have been conducted within a 0.50-mile radius. Of those, 15 intersect with portions of the project site (Table 1, Previous Studies within 0.50-Mile Buffer). Five resources (four historic structures and one prehistoric isolate) were previously recorded within the 0.50-mile radius. One resource, the Atchison, Topeka & Santa Fe Railroad Bridge (ATS Bridge) aka Burlington Northern Santa Fe Railroad (P-30-176663) crosses over the project site.

The ATS Bridge was evaluated in 1987 by Roger Hatheway. According to the study:

The existing structure is not the original Santa Fe railroad bridge built to cross the Santa Ana River at this point. The earlier structure was replaced in 1916 and again in 1938 as a result of flood damage. The present structure is interesting, however, in that it is of a seemingly inordinate length. An answer to this problem is found through an examination of additional U.S.G.S. Maps. The 1950 edition clearly shows that the river channel widened considerably at this point. This may have been a result of either the 1916 or 1938 floods. The river channel has since been narrowed considerably, hence the anomaly between the B I Harris & Associates
5 bridge length and width of the river channel. The present bridge is, therefore, of engineering interest, although it is not of a unique design, method of construction, or of outstanding historical interest.

The bridge does not possess a high degree of integrity as the original structure was replaced more than once. The present structure contains portions of a 1916 bridge, but is primarily a 1938 structure. The setting has also been altered, including the narrowing of the river channel. The majority of the structure is not more than 50 years old. This fact should, however, not be a major determining factor as the bridge is only one year less old than the 50-year eligibility date. The structure does not possess high artistic or design value as it is a simple standardized well deck girder common throughout California. The structure itself does not have significant historical associations. It is part of a major and historic transportation system, but was not one of the first or most significant elements of this system. The structure does represent unusual scale in terms of its overall length. The structure is not an unusual or rare surviving example of its type.

The study determined that the ATS Bridge did not meet criteria for eligibility to the National Register of Historic Places.

Table 1. Prior Studies within 0.50-Mile Buffer
Study # Title Author Year
OR-00270 Description and Evaluation of Cultural Resources Within the US Army Corps of Engineers' Santa Ana River Project Leonard, Nelson N. III
and Matthew C. Hall 1975
OR-00609 Cultural Resources Report on 5 Proposed Hazardous Waste Storage Sites Located in Northern Orange County,
California
Desautels, Mark
1981
OR-00801 Phase II Archaeological Studies Prado Basin and the Lower Santa Ana River
Langenwalter, Paul E.
and James Brock 1985
OR-00814 ARCHAEOLOGICAL SURVEY REPORT for the Route I-5 Santa Ana Transportation Corridor, Route 405 in Orange
County to Route 605 in Los Angeles County Pm

21.30/44.38; 0.00/6.85
Romani, John F.
1982
OR-00894 An Archaeological Survey of the Orange Drive-in Thester Property Orange, California
McKenna, Jeanette A.
and Hatheway, Roger
G.
1988
OR-00895 Archaeological Survey Report: Villa Park-Lewis 230 Kv Transmission Line Right-Of-Way Orange County,
California
Taylor, Thomas T. 1988
OR-01162 Monitoring Report for the Sports Arena in the City of Anaheim
Brown, Joan C. 1991
OR-01806 Cultural Resources Records Search and Literature Review Report for a Pacific Bell Mobile Services
Telecommunications Facility: Cm 069-12 Anaheim,
Orange County, California
Mason, Roger D. 1998
OR-01836 Cultural Resource Review for Groundwater
Replenishment System Program EIR/Tier I/EIS, Orange
County Water District and County Sanitation Districts of Orange County
Padon, Beth 1998
OR-01900 Historical and Architectural Evaluation of Four Railroad Bridges, Lower Santa Ana River and Santiago Creek
Orange County, California
Hatheway, Roger G. 1987
OR-02091 Cultural Resources Assessment for Pacific Bell Wireless Facility CM 282-02, County of Orange, California
Lapin, Philippe 2000
B I Harris & Associates
6 Table 1. Prior Studies within 0.50-Mile Buffer
Study # Title Author Year
OR-02141 Inspection of Kinder Morgan Energy Partners Electrical Substation and Control Building Proposed Sites, Orange
County.

Self, William 2000
OR-02200 Cultural Resources Investigation for the Nextlink Fiber Optic Project, Los Angeles and Orange Counties,
California.

Atchley, Sara M. 2000
OR-02256 Cultural Resources Assessments for Orange County Sanitation Districts.

Demcak, Carol R. 1999
OR-02354 Review of Cultural Resource Assessment/Evaluation for Cingular Wireless Site CM-282-03, Orange County,
California.

McKenna, Jeanette A. 2001
OR-02503 Construction of a Vehicular Parking Area Within a Portion of Caltrans Right-of-way Near the Southeasterly Corner
of the Orange Freeway (State Route 57) Interchange at
Ball Road in Anaheim.

Shepard, Richard S. 2001
OR-02587 Revised Archaeological/Paleontological Monitoring Report for Arena Corporate Center Project, Contract
Number PO#1058, Project #714375-01
Brown, Joan C. 2002
OR-02765 The Pinnacle at Uptown Orange McKenna, Jeanette A. 2002 OR-02828 Archaeological Monitoring During Excavations for the Westwood College Project, Anaheim, California
Brown, Joan C. 2003
OR-02911 Sunkist Gardens, City of Anaheim, Orange County, California
Garcia, Kyle H. 2005
OR-03090 Taft/CA-8214 1320 South Sanderson Avenue, Anaheim, Ca Orange County
Thal, Sean and Lorna
Billat
2004
OR-03097 Cultural Resources Records Search Results and Site Visit for Sprint Nextel Candidate Ca7061 (monterey), 2023
West Collins Avenue, Orange, Orange County, California
Bonner, Wayne H. 2006
OR-03108 Cultural Resource Records Search and Site Visit for Cingular Telecommunications Facility Candidate Sc-043-
02 (Calvary Baptist Church), 2780 East Wagner Avenue,
Anaheim, Orange County, California
Bonner, Wayne H. 2003
OR-03287 Historic Property Survey Report for Tustin Branch Trail Network, City of Orange, Orange County, California
Mason, Roger D. 2002
OR-03373 Cultural Resources Final Report of Monitoring and Findings for the Qwest Network Construction Project
State of California: Volumes I and Ii
Arrington, Cindy and
Nancy Sikes
2006
OR-03651 Cultural Resources Records Search and Site Visit Results for Royal Street Communications, LLC Candidate
LA2658A (SCE Barre Villa Park M6-T6), 1511 North Main
Street, Orange County, California
Bonner, Wayne H. and
Kathleen A. Crawford
2007
OR-03654 Direct APE Historic Architectural Assessment for Royal Street Communications, LLC Cadidate LA2658A (SCE
Barre Villa Park M6-T6), 1511 North Main Street, Orange, Orange County, California
Bonner, Wayne H. and
Kathleen A. Crawford
2007
B I Harris & Associates
7 Table 1. Prior Studies within 0.50-Mile Buffer
Study # Title Author Year
OR-04017 Cultural Resources Records Search and Site Visit Results for T-Mobile USA Candidate LA33523-A (Dupont
Commercial), 2165 Dupont Drive, Anaheim, Orange
County, California
Bonner, Wayne H. 2011
OR-04087 Program EIR/Tier 1 EIS, for the Groundwater
Replenishment System
Salenius, Sylvia 1998
OR-04091 Cultural Resources Assessment for the Burris Basin Interpretive Loop Trail and the Lincoln Avenue Multi-Use Staging Area, City of Anaheim, Orange County, California Fulton, Terri 2009
OR-04113 Cultural Resources Study of the Anaheim Stadium Project, AT&T Site No. OC0360, 2000 E. Gene Autry Way,
Anaheim, Orange County, California 92806
Supernowicz, Dana E. 2010
OR-04156 Draft, Phase I Archaeological Resources Survey Report, Anaheim Regional Transportation Intermodal Center
Project City of Anaheim, Orange County, California
Wood, Catherine M. 2009
OR-04259 Cultural Resources Monitoring Report, Orange County Water District Groundwater Replenishment System,
Orange County, California
Becker, Kenneth,
Goodman, John,
Sewell, Kristin, and
Van Galder, Sarah
2007
OR-04266 Cultural Resources Reconnaissance for the
Groundwater Replenishment System, Orange County,
California
Bissell, Ronald M. 2000
OR-04291 Results of Rough Grade Monitoring for the Artic Project in the City of Anaheim, CA
Taft, Ryan 2012
OR-04367 Cultural Resources and Paleontological Resource -- Phase I Assessment for the Orange County Water
District's Ball Road Basin General Plan Amendement
and Zone Change Project, City of Anaheim, Orange
County, California
Akyuz, Linda 2013
OR-04470 Cultural Resources Records Search and Site Visit Results for T-Mobile West, LLC Candidate LA02069A (CM069
Anaheim Auto Center Sign) 1383 South Auto Center
Drive, Anaheim, Orange County, California
Bonner, Wayne H. 2013
Bold = Studies that intersect with the project site.

Table 2. Previously Recorded Cultural Resources within 0.50-Mile Buffer Primary Number Trinomial
Chronological
Placement1 Site Type Resource Name
P-30-100402 N/A Prehistoric Isolate - Mano Isolate 1
P-30-176663 N/A Historic Structure- Railroad Atchison, Topeka & Santa Fe Railroad
(aka Burlington
Northern Santa Fe
Railroad)
P-30-177113 N/A Historic Structure- Stadium Angel Stadium of Anaheim
P-30-177465 N/A Historic Structure- Basin and
Channel
Fletcher Retarding
Basin and Channel
B I Harris & Associates

I I I I
8 Table 2. Previously Recorded Cultural Resources within 0.50-Mile Buffer Primary Number Trinomial
Chronological
Placement1 Site Type Resource Name
P-30-177610 N/A Historic StructureTransmission TowerSCE M6 T6 Barre Villa Park Transmission
Tower
Note: 1 This column indicates the time period for each resource type that was recorded from previous studies but does not determine whether a resource qualifies as a historical resource under CEQA Guidelines Section 15064.5.

Bold = Resources that intersect with the project site.

Applicable Regulations
Cultural resource regulations that apply to the project site are CEQA, the California Health and Safety Code, and provisions of the California Register of Historical Resources (CRHR). Historic and archaeological districts, sites, buildings, structures, and objects are assigned significance based on their exceptional value or quality in illustrating or interpreting the heritage of the Citiesin history, architecture, archaeology, engineering, and culture.

Several criteria are used in demonstrating resource importance.

State Level Regulations
California Environmental Quality Act
According to CEQA, a resource shall be considered by the lead agency to be “historically significant” if the resource meets the criteria for listing on the CRHR (PRC Section 5024.1; 14 CCR 4852) including the following:

1. Is associated with events that have made a significant contribution to the broad patterns of California’s history and cultural heritage;

2. Is associated with the lives of persons important in our past;

3. Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of an important creative individual, or possesses high artistic values; or

4. Has yielded, or may be likely to yield, information important in prehistory or history.

The fact that a resource is not listed in or determined to be eligible for listing in the CRHR, not included in a local register of historical resources (pursuant to PRC Section 5020.1(k)), or not identified in an historical resources survey (meeting the criteria in PRC Section 5024.1[g]) does not preclude a lead agency from determining that the resource may be an historical resource as defined in California Public Resources Code, Section 5020.1(j) or 5024.1.

CEQA also requires that Tribal Cultural Resources be considered and are defined in California Public Resources Code, Section 21074, as follows:
(a) “Tribal cultural resources,” are either of the following:

1. “Sites, features, places, cultural landscapes, sacred places, and objects with cultural value to a California Native American tribe that are either of the following:

A. Included or determined to be eligible for inclusion in the California Register of Historical Resources.

B. Included in a local register of historical resources as defined in subdivision (k) of Section 5020.1” (discussed below).

2. A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of Section 5024.1. In applying the criteria set forth in subdivision (c) of Section 5024.1 for the purposes of this paragraph, the lead agency shall consider the significance of the resource to a California Native American tribe.

B I Harris & Associates
9 (b) A cultural landscape that meets the criteria of subdivision (a) is a tribal cultural resource to the extent that the landscape is geographically defined in terms of the size and scope of the landscape. (c) A historical resource described in Section 21084.1, a unique archaeological resource as defined in subdivision (g) of Section 21083.2, or a “nonunique archaeological resource” as defined in subdivision (h) of Section 21083.2 may also be a tribal cultural resource if it conforms with the criteria of subdivision (a).” California Register of Historical Resources (PRC Section 5020 et seq.) In California, the term “historical resource” includes but is not limited to “any object, building, structure, site, area, place, record, or manuscript which is historically or archaeologically significant, or is significant in the architectural, engineering, scientific, economic, agricultural, educational, social, political, military, or cultural annals of California” (PRC Section 5020.1[j]). In 1992, the California Legislature established the CRHR “to be used by state and local agencies, private groups, and citizens to identify the state’s historical resources and to indicate what properties are to be protected, to the extent prudent and feasible, from substantial adverse change” (PRC Section 5024.1[a]). A resource is eligible for listing in the CRHR if the State Historical Resources Commission determines that it is a significant resource and that it meets any of the following National Register of Historic Places (NRHP) criteria (PRC Section 5024.1[c]):

1. Associated with events that have made a significant contribution to the broad patterns of California’s history and cultural heritage.

2. Associated with the lives of persons important in our past.

3. Embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of an important creative individual, or possesses high artistic values.

4. Has yielded, or may be likely to yield, information important in prehistory or history.

Resources less than 50 years old are not considered for listing in the CRHR but may be considered if it can be demonstrated that sufficient time has passed to understand the historical importance of the resources (refer to 14 CCR 4852[d][2]).

The CRHR protects cultural resources by requiring evaluations of the significance of prehistoric and historical resources. The criteria for the CRHR are nearly identical to those for the NRHP, and properties listed or formally designated as eligible for listing on the NRHP are automatically listed on the CRHR, as are the state landmarks and points of interest. The CRHR also includes properties designated under local ordinances or identified through local historical resource surveys. The State Historic Preservation Officer maintains the CRHR.

California Health and Safety Code, Section 7050.5
California law protects Native American burials, skeletal remains, and associated grave goods, regardless of their antiquity, and provides for the sensitive treatment and disposition of those remains. California Health and Safety Code, Section 7050.5, requires that, if human remains are discovered in any place other than a dedicated cemetery, no further disturbance or excavation of the site or nearby area reasonably suspected to contain human remains shall occur until the county coroner has examined the remains (Section 7050.5b). If the coroner determines or has reason to believe the remains are those of a Native American, the coroner must contact the Native American Heritage Commission (NAHC) within 24 hours (Section 7050.5c). The NAHC will notify the most likely descendant (MLD). With the permission of the landowner, the MLD may inspect the site of discovery.

The inspection must be completed within 24 hours of notification of the MLD by the NAHC. The MLD may recommend means of treating or disposing of, with appropriate dignity, the human remains and items associated with Native Americans.

City of Anaheim Regulations
General Plan (2004)
The General Plan (City of Anaheim 2004b) includes the following goals and policies related to Historical Resources that are specific to residential areas of the Anaheim Colony. However, those goals and policies do not apply to this B I Harris & Associates
10 project. No goals or policies are included in the General Plan related to archaeological resources or human remains.

Citywide Historic Preservation Plan (2010)
The City approved the Citywide Historic Preservation Plan (Plan) (City of Anaheim 2010) on May 18, 2010. The plan supplements the 1999 Anaheim Colony Historic District Preservation Plan and applies to the four historic districts (Anaheim Colony, Five Points, Historic Palm, and Hoskins) within the City. The Plan does not apply to this project.

Anaheim Colony Historic District Preservation Plan (1999) The Anaheim Colony Historic District Preservation Plan (Preservation Plan) (City of Anaheim 1999) provides basic guidelines, and encourages property owners to take special care in preserving, protecting, or enhancing historic buildings. This plan does not apply to this project.

City of Orange
General Plan
The General Plan (City of Orange 2010b) includes goals and policies related to Cultural Resources and Historic Preservation. The Cultural Resources and Historic Preservation Element (Element) is based on prior actions taken to recognize historic resources, and is an effort to expand the City’s historic preservation program to ensure recognition and preservation of the City’s resources. The Element provides guidelines to preserve those resources that represent the history and culture of Orange. Specifically, its purpose is to provide guidance in developing and implementing programs that ensure the identification, designation, and protection of cultural resources in the City’s planning, development, and permitting process. The Element also identifies ways in which the City can encourage and coordinate with private property owners in support of historic preservation. The following goals and policies are identified in the Element:

Architecture and Community Character
Goal 1.0: Identify and preserve potential and listed historic resources, including buildings, structures, objects, sites, districts, and archaeological resources citywide.

Policy 1.1: Maintain an accessible inventory of designated and potential historic resources.

Policy 1.2: Promote community education and awareness of the significance of Orange’s potential and listed historic resources.

Policy 1.3: Provide long term assurance that potential and listed historic resources will be used, maintained, and rehabilitated in conformance with Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring and Preserving Historic Buildings (Secretary’s Standards).

Policy 1.4: Encourage alternatives to demolition such as architecturally-compatible rehabilitation, adaptive re-use, new construction, and relocation.

Policy 1.5: Require that no permit for alteration or demolition of properties identified in the Orange Historic Resources Inventory as potential historic resources shall be issued until alternatives to demolition have been duly considered.

Policy 1.6: Promote the preservation of cultural and historical resources controlled by governmental agencies, including those related to City, School District, and other agencies.

Preserving Historic Neighborhood Character
B I Harris & Associates
11 Goal 2.0: Identify and preserve neighborhoods that are culturally and historically significant but do not retain sufficient integrity for eligibility as a local, state, or national district.

Policy 2.1: Encourage identification and listing of Neighborhood Character Areas within the El Modena, Cypress Street Barrio, Railroad/Packinghouse Corridor, and Orange Park Acres neighborhoods.

Policy 2.2: Promote community and visitor awareness and education concerning the unique and special history and architecture found in Neighborhood Character Areas.

Policy 2.3: Ensure that those qualities that contribute to the historic character of designated Neighborhood Character Areas are retained through application of design guidelines consistent with the local context and key physical attributes of each neighborhood.

Incentives and Education
Goal 3.0: Provide incentives and expand education efforts for historic preservation.

Policy 3.1: Expand education efforts to facilitate and encourage historic preservation and recognition of the City’s historic resources.

Policy 3.2: Provide incentives to encourage and support historic preservation.

Policy 3.3: Actively seek funding for historic preservation activities.

Policy 3.4: Leverage recognition of the City’s historic preservation program, participate directly in federal and state historic preservation programs, and gain access to designated historic preservation funding.

Policy 3.5: Explore additional funding sources for maintenance and rehabilitation of historic resources.

Archaeological and Cultural Resources
Goal 4.0: Identify and preserve archaeological and cultural resources.

Policy 4.1: Identify, designate, and protect historically and culturally significant archaeological resources or sites.

Policy 4.2: Recognize the importance of Santiago Creek as an archaeological resource.

Policy 4.3: Encourage curation of any cultural resources and artifacts recovered in the City for public education and appreciation.

Policy 4.4: Celebrate the cultural history of the community by increasing community awareness through the design features of public projects and facilities such as parks, plazas, and community buildings.

Policy 4.5: Encourage private development to celebrate the cultural history of the community through project design.

Policy 4.6: Provide additional resources and promotion for the Orange Public Library Local History Collection.

Native American Traditional Cultural Properties
Native American Heritage Values
Federal and state laws mandate that consideration be given to the concerns of contemporary Native Americans with regard to potentially ancestral human remains, associated funerary objects, and items of cultural patrimony.

Consequently, an important elementin assessing the significance of the study site has been to evaluate the likelihood that these classes of items are present in areas that would be affected by the project.

B I Harris & Associates
12 Also, potentially relevant to prehistoric archaeological sites is the category termed Traditional Cultural Properties in discussions of cultural resources management performed under federal auspices. According to Parker and King (1998), “traditional” in this context refers to those beliefs, customs, and practices of a living community of people that have been passed down through the generations, usually orally or through practice. The traditional cultural significance of a historic property, then, is significance derived from the role the property plays in a community’s historically rooted beliefs, customs, and practices. Examples of properties possessing such significance include the following:

1. A location associated with the traditional beliefs of a Native American group about its origins, its cultural history, or the nature of the world;

2. A rural community whose organization, buildings and structures, or patterns of land use reflect the cultural traditions valued by its long-term residents;

3. An urban neighborhood that is the traditional home of a particular cultural group, and that reflects its beliefs and practices;

4. A location where Native American religious practitioners have historically gone, and are known or thought to go today, to perform ceremonial activities in accordance with traditional cultural rules of practice; and

5. A location where a community has traditionally carried out economic, artistic, or other cultural practices important in maintaining its historic identity.

A Traditional Cultural Property, then, can be defined generally as one that is eligible for inclusion in the NRHP because of its association with cultural practices or beliefs of a living community that (1) are rooted in that community’s history and (2) are important in maintaining the continuing cultural identity of the community.

Methodology
The goal of this survey was to provide a constraints-level survey to identify the location of any cultural resource that may be present on site. Jasmine Alvarez-Ceja, Harris & Associates Junior archaeologist, conducted the survey on July 30, 2024. The survey was conducted in 5- to 10-meter transects. The project site is developed and is primarily developed and covered in disturbed habitat. Dumping on site is evident, and visibility was high due to the paved concrete walkways, dirt patches and dried vegetation. The survey area was relatively level, and greater assessment was focused on open areas.

Historical topographic maps and historical aerials were reviewed from 1946 to 2022 (1946, 1952, 1963, 1972, 1980, 1985, 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997,1998, 1999, 2000, 2002, 2003, 2004, 2005, 2009, 2010, 2012, 2014, 2016, 2018, 2020, and 2022). From 1946 through 1952, the project site was undeveloped except for the presence of railroad tracks, agricultural uses and Interstate 5 nearby. By 1963, major roads (Katella Avenue, Struck Avenue, Ball Road, and Taft Avenue) are present or under construction. By 1972, residential and commercial development is present in the surrounding areas including Angels Stadium. State Route 57 is present by 1980. Development in the area remains essentially static through 2022.

This cultural study will be submitted to the South Central Coastal Information Center.

Results
The ATS Bridge that was previously determined not eligible for listing to the NRHP is present in the southern portion of the project site. No changes to the bridge were identified (see photos 21, 39, and 44) and no new information was identified during the preparation of this report. The ATS Bridge is not eligible for listing to either the NRHP or CRHR; as such, it is not significant under CEQA. It will not be impacted by the project because it crosses over the project site. No other resources were identified during the pedestrian survey.

Native American Outreach
The NAHC was contacted for a Sacred Lands File Check to determine whether sacred lands are present on site.

The NAHC responded that the check yielded no previously known Native American sacred sites. Outreach to the list of Tribes in the NAHC response letter has been conducted (refer to Confidential Attachment 4, Sacred Lands Tribal Outreach). To date, no responses have been received from the Tribes.

B I Harris & Associates
13 Recommendations
No historical or archaeological resources were identified during the cultural survey. The APE is developed and has been historically disturbed. Because of the developed/disturbed nature of the project site and the lack of resources within the project site, no additional work or mitigation is recommended.

If you have any questions, please contact me at (619) 236-1778.

Sincerely,
Donna Beddow, RPA
Senior Archaeologist
Attachments
1 – Figures
2 – Photographs
Confidential Attachments – Under Separate Cover
Confidential Attachment 3 – CHRIS Background Data
Confidential Attachment 4 – Sacred Lands Tribal Outreach References
City of Anaheim. 2004. Final Anaheim General Plan and Zoning Code Update Environmental Impact Report, No. 330, SCH#2003041105, Volume I, Section 5.4. Accessed August 2024. https://www.anaheim.net/DocumentCenter/View/2186/54-Cultural-Resources-?bidId= City of Anaheim. 2003. The Anaheim Colony – Vision, Principles and Design Guidelines. Accessed August 2024. https://www.anaheim.net/DocumentCenter/View/2029/X-Colony-Design-Guidelines-?bidId= City of Anaheim. 2010. Citywide Historic Preservation Plan. Accessed August 2024. https://anaheim.net/DocumentCenter/View/1485/Citywide-Historic-Preservation-Plan-?bidId= City of Orange. 2010a. Program Environmental Impact Report – Orange General Plan. Accessed August 2024. https://www.cityoforange.org/home/showpublisheddocument/240/637698173340500000 City of Orange. 2010b. Orange General Plan. Accessed August 2024. https://www.cityoforange.org/ourcity/departments/community-development/general-plan Hatheway, Roger. 1987. Historical and Architectural Evaluation of Four Railroad Bridges, Lower Santa Ana River and Santiago Creek, Orange County, California. Unpublished manuscript on file at the South Central Coastal Information Center, California State University, Fullerton.

NETR Online. 2024. Historic Aerials. Accessed July 2024. http://www.historicaerials.com.

Parker, Patricia L., and Thomas F. King. 1998. Guidelines for Evaluating and Documenting Traditional Cultural Properties. U.S. Department of the Interior, National Park Service, National Register, History and Education, National Register of Historic Places. 1990, revised 1992 and 1998. = I Harris & Associates
14 National Archaeological Data Base Information
Authors: Donna Beddow and Jasmine Alvarez-Ceja
Firm: Harris & Associates
101 Progress
Irvine, CA 92618
(949) 655-3900
Client/Project Proponent: City of Anaheim
Community Service Department, Park Division
200 S. Anaheim Boulevard, Suite 433
Anaheim, California 92805
Contact: Ana Straabe, Principal Project Planner
Report Date: October 3, 2024
Report Title: Orange County River Walk Project; Cultural Resources Survey Letter Report – Negative Findings
Type of Study: Intensive Pedestrian/Phase I
New Sites: None
Updated Sites: P-30-176663
USGS Quad: Anaheim
Acreage: 90 acres
Key Words: Historic, P-30-176663, Atchison, Topeka & Santa Fe Railroad Bridge aka Burlington Northern Santa Fe Railroad, Anaheim USGS Quad, Pedestrian Survey B I Harris & Associates
Attachment 1. Figures
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Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure1_Regional.mxd Dana
Point
San Juan
Capistrano
Laguna
Beach
Laguna
Hills Coto De
Caza
Newport
Beach Mission
Viejo
Trabuco
Highlands
Costa
Mesa
Irvine
Huntington
Beach
Tustin
Seal
Beach
Garden
Grove
Orange
Anaheim
Placentia Yorba Linda
Fullerton
Corona
March
Woodcrest AFB
Norco
Riverside
Rubidoux
Wildomar
Lake
Elsinore
Carson
Long
Beach
Cerritos
Gardena Bellflower Compton
Downey
Diamond
Bar
Industry
Walnut
Alhambra Covina
Pomona
Claremont
Glendora
Irwindale
Burbank Monrovia
Altadena
Pasadena Glendale
Acton
Chino
Hills
Chino
Loma
Linda
Ontario Bloomington Colton
Upland Fontana Rialto
Crestline
Hesperia
Victorville
Cypress
nglewood
Whittier
Commerce
Montebello
Rosemead
Arcadia
Los Angeles County
Orange County
San Bernardino County
Los Angeles County
Riverside County
Orange County
Orange County
San Diego
County
P a c i f i c O c e a n
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£¤395
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OC River Walk Project
Incorporated Areas
Project Site
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Regional Location
Source: ESRI 2020.

Figure 1 ± 0 5 10
■ MilesHarris & Associates
ÄÆ57
ÄÆ57
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HILDA ST

WINSTON RD

TURIN AVE

POPLAR ST

CASE ST

PALMYRA AVE

ECKHOFF ST

ANITA DR

CULLY DR

PACIFIC ST

SOUTH ST

SINCLAIR ST

ALMOND AVE

MAPLE AVE

NYON AVE

CLIFPARK WAY

FELDNER RD

CULVER AVE

CHANTILLY ST

CITRUS ST

VERMONT AVE

JEWELL PL

PALM AVE

ORANGE ST

GRAND ST

SYCAMORE AVE

STRUCK AVE

LEMON ST

OLIVE ST

PIXLEY ST

CYPRESS ST

PARKER ST

MARJAN ST

GROVE AVE

VERNON ST

SUNKIST ST

DOUGLASS RD

ECKHOFF ST

ANAHEIM WAY

LEWIS ST

MANCHESTER AVE

FLETCHER AVE

ORANGEWOOD AVE

BATAVIA ST

HOWELL AVE

THE CITY DR

STATE COLLEGE BLVD

TAFT AVE

RAMPART ST

GLASSELL ST

FLOWER ST

LA VETA AVE

RIO VISTA ST

COLLINS AVE

CHAPMAN AVE

WALNUT AVE

EAST ST

MAIN ST

CERRITOS AVE

GROVE AVE

WAGNER AVE

BALL RD

GENE AUTRY WAY

KATELLA AVE
Project Site
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure2_ProjectSite.mxd Project Site
Source: Eagle Imagery 2017.
± 0 1,000 2,000 Figure 2
Feet
OC River Walk Project
• Harris & Associates
-
Project Site
Date: 6/30/2023 - Last saved by: Randy.Deodat - Path: C:\GIS\Projects\City of Anaheim\OC River Walk\Map Docs\Bio\BTR\Figure3_USGS.mxd USGS Topographic Map
Source: USGS 7.5 Minute Anaheim and Orange Quadrangles 1974. ± 0 1,000 2,000 Figure 3
Feet
OC River Walk Project
Q •• I
■ Harris & Associates
Attachment 2. Photographs
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Cultural Resources Letter Report November 2024
OC River Walk
Photograph 1: Project site from Orangewood Avenue,
facing northeast.

Photograph 2: Project site from Orangewood Avenue,
facing north.

Photograph 3: Project site between Orangewood
Avenue and Katella Avenue, facing north.

Photograph 4: Katella Avenue underpass, facing east. Photograph 5: Katella Avenue underpass, typical ground visibility, facing north.

Photograph 6: Northwestern portion of project site.

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 7: Southern portion of project site, facing
north.

Photograph 8: Northern portion of project site. Typical cleared area.

Photograph 9: Southern portion of project site, facing
east.

Photograph 10: South of Katella Avenue underpass.

Typical view of Santa Ana River.

Photograph 11: Katella Avenue underpass, facing
north.

Photograph 12: North side of Katella Avenue, facing
east.

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 13: Western portion of river, facing
northeast.

Photograph 14: Typical view of Santa Ana River, facing
east.

Photograph 15: Typical area between pedestrian trail
and river, facing north.

Photograph 16: Santa Ana River between Katella
Avenue and East Ball Road.

Photograph 17: Santa Ana River, typical view, facing
east.

Photograph 18: Santa Ana River, facing southeast..

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 19: Santa Ana River, facing east. Photograph 20: Project site between Katella Avenue and East Ball Road, facing northeast.

Photograph 21: North portion of railroad tracks, facing east.

Photograph 22: Between railroad tracks and East Ball
Road, facing northeast.

Photograph 23: South side of East Ball Road, facing
east.

Photograph 24: Project site from north side of East Ball Road.

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 25: Fenced section of East Ball Road,
facing west.

Photograph 26: Fenced section of East Ball Road,
facing northwest.

Photograph 27: Fenced section of East Ball Road,
typical ground visibility, facing north.

Photograph 28: Fenced section of East Ball Road,
typical ground visibility, facing west.

Photograph 29: Project site from pedestrian trail, facing south.

Photograph 30: Project site from pedestrian trail,
typical ground visibility, facing east.

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 31: Typical ground visibility from pedestrian trail, facing east.

Photograph 32: Project site from pedestrian trail, facing south.

Photograph 33: Typical ground visibility from
pedestrian trail, facing east.

Photograph 34: East side of project site, facing north. Photograph 35: East side of project site, facing northwest.

Photograph 36: East side of project site, facing north.

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 37: East side of project site from
pedestrian trail, facing northwest.

Photograph 38: East side of project site from
pedestrian trail, facing north.

Photograph 39: East side of project site from
pedestrian trail, facing north.

Photograph 40: East side of project site from
pedestrian trail, facing north.

Photograph 41: East side of project site from
pedestrian trail, facing northwest.

Photograph 42: East side of project site, facing south
towards Taft Street.

Cultural Resources Letter Report November 2024
OC River Walk
Photograph 43: East side of project site, facing south. Photograph 44: East side of project site from pedestrian trail, facing south.

Photograph 45: East side of project site from
pedestrian trail, facing southwest.

Photograph 46: East side of project site from
pedestrian trail, facing south.

Attachment 3. CHRIS Background Data
Under Separate Cover – See Confidential Attachments
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Attachment 4. Sacred Lands Tribal Outreach
Under Separate Cover – See Confidential Attachments
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Appendix F. Geotech Report
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Preliminary Geotechnical Evaluation
OC River Walk
Anaheim and Orange, California
Pacific Advanced Civil Engineering
17520 Newhope Street, Suite 200 | Fountain Valley, California 92708 October 11, 2024 | Project No. 212076001
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS Geotechnical & Environmental Sciences Consultants
475 Goddard, Suite 200 | Irvine, California 92618 | p. 949.753.7070 | www.ninyoandmoore.com Preliminary Geotechnical Evaluation
OC River Walk
Anaheim and Orange, California
Mr. Jacob Peterson
Pacific Advanced Civil Engineering
17520 Newhope Street, Suite 200 | Fountain Valley, California 92708 October 11, 2024 | Project No. 212076001
Spencer Marcinek, PE, GE
Senior Engineer
Michael Putt, PG, CEG
Principal Geologist
Soumitra Guha, PhD, PE, GE
Principal Engineer
SCM/MLP/SG/lva
Gaolechnical l Environmental Sc:iancH Consullants
Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 i

CONTENTS
1 INTRODUCTION 1
2 SCOPE OF SERVICES 1
3 BACKGROUND AND PROPOSED CONSTRUCTION 1
4 PREVIOUS GEOTECHNICAL STUDIES 3
5 GEOLOGY AND SUBSURFACE CONDITIONS 4

5.1 Regional Geology 4

5.2 Site Geology 4
6 GROUNDWATER 5
7 FLOOD HAZARDS 6
8 FAULTING AND SEISMICITY 6

8.1 Surface Fault Rupture 6

8.2 Strong Ground Motion 6

8.3 Liquefaction and Seismically Induced Settlement 7

8.4 Lateral Spreading 7

8.5 Tsunamis and Seiches 8
9 SLOPE STABILITY ANALYSES 8
10 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS 10

10.1 Earthwork 12

10.1.1 Construction Plan Review and Pre-Construction Conference 12

10.1.2 Site Clearing 12

10.1.3 Excavation Characteristics 13

10.1.4 Remedial Grading for Improvements on Shallow Foundations 13

10.1.5 Treatment of Near-Surface Soils for the Santa Ana River Trail 14

10.1.6 Temporary Excavations and Shoring 14

10.1.7 Construction Dewatering 15

10.1.8 Slopes 15

10.1.9 Fill Material 16

10.1.10 Fill Placement and Compaction 17

10.1.11 Pipe Bedding 18

10.1.12 Modulus of Soil Reaction 18
Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 ii

10.2 Foundations 18

10.2.1 Pile Design Considerations 18

10.2.2 Driven Pile Construction Considerations 19

10.2.3 CIDH Pile Construction Considerations 20

10.2.4 Pole Foundations 21

10.2.5 Spread Footings and Mats 22

10.2.6 Slabs-On-Grade 23

10.3 Retaining Walls 23

10.3.1 Tieback Anchors 24

10.3.2 Tieback Anchor Construction Considerations 25

10.3.3 Tieback Anchor Testing 25

10.4 Preliminary Pavement Design 27

10.5 Decomposed Granite Trails 28

10.6 Corrosivity 28

10.7 Concrete Placement 29

10.8 Drainage 29
11 CONSTRUCTION MONITORING PROGRAM 30

11.1 Documentation of Existing Conditions 30

11.2 Construction Vibrations 30

11.3 Ground Surface Settlement 31

11.4 Lateral Movement for Shoring Support System 31

11.5 Groundwater Monitoring 31
12 ADDITIONAL GEOTECHNICAL STUDIES 31
13 LIMITATIONS 32
14 REFERENCES 33
TABLES
1 – Groundwater Levels in Monitoring Wells 5
2 – Material Properties Used in Slope Stability Evaluation 9 3 – Summary of Slope Stability Analyses 10
4 – Preliminary Structural Pavement Sections 27
Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 iii

FIGURES
1 – Site Location
2 – Proposed Boring Locations
3 – Site Plan With Boring and CPT Sounding Locations
4 – Regional Geology
5 – Cross Section A-A’
6 – Fault Locations
7 – Caltrans Acceleration Response Spectrum
8 – Seismic Hazard Zones
9 – Lateral Earth Pressures for Braced Excavation Below Groundwater 10 – Lateral Earth Pressures for Temporary Cantilevered Shoring Below Groundwater 11 – Keying and Benching Detail
12 – Lateral Earth Pressures for Yielding Retaining Walls 13 – Lateral Earth Pressures for Restrained Retaining Walls 14 – Retaining Wall Drainage Detail

APPENDICES
A – Previous Boring Logs and CPT Soundings
B – Previous Laboratory Testing
C – Slope Stability Analyses
D – Pile Axial Capacity Plots
Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 1 1 INTRODUCTION
In accordance with your request and authorization, we have performed a preliminary geotechnical evaluation for the City of Anaheim’s Orange County (OC) River Walk Project in the cities of Anaheim and Orange, California (Figure 1). We are currently providing geotechnical consulting services for the project. We previously prepared a Drilling Program Plan dated March 31, 2023, which is required by the United States Army Corps of Engineers (USACE) in order to drill borings within earth embankments under their jurisdiction. The USACE has not approved the Drilling Program Plan and they have informed the project team that Section 404 and 408 permission is needed prior to approving our proposed subsurface exploration.

We understand that Section 404 and 408 permission is a lengthy process and that as part of the USACE’s review of those applications, detailed construction drawings will need to be submitted.

Therefore, we have been requested to prepare a preliminary geotechnical evaluation report in order to facilitate the preparation of the construction drawings. The purpose of our study was to summarize the existing geotechnical data for the site and to provide preliminary geotechnical design considerations and geotechnical design parameters for the planned improvements. Once the Drilling Program Plan has been approved, we will perform site-specific borings, perform supplemental geotechnical engineering analyses, and prepare an updated geotechnical evaluation report for the project based on the findings from our subsurface evaluation. 2 SCOPE OF SERVICES
Our scope of services included the following:
• A review of readily available existing geotechnical information pertinent to the project including documents made available by Pacific Advanced Civil Engineering (PACE) and our in-house files.
• Review of existing as-built drawings and consultation with the project engineer regarding the geotechnical aspects of proposed construction.
• Data compilation and engineering analyses of the information obtained from our background review.
• Preparation of this preliminary geotechnical report presenting our findings, conclusions, and preliminary recommendations pertaining to the design and construction of the proposed improvements.
3 BACKGROUND AND PROPOSED CONSTRUCTION
The proposed OC River Walk project site is located within the Santa Ana River corridor between East Ball Road (or West Taft Avenue) to the north and Orangewood Avenue to the south (Figures 1 Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 2 and 2). The Santa Ana River is a trapezoidal open channel with an unlined bottom and grouted rip-rap constructed on both banks of the existing channel. The Santa Ana River generally flows southwest and discharges into the Pacific Ocean. The topography of the project site consists of a trapezoidal river channel with approximately 15- to 20-foot-high embankment slopes with a gentle sloping trend overall towards the southwest.

The OC River Walk project will include constructing two river impoundment structures and making modifications to the existing Santa Ana River embankment slopes (Figure 3). The new impoundment structures will create two ponded water surface areas totaling approximately 38 acres that will allow for year-round infiltration of stormwater and infiltration of purified water delivered from the Orange County Water District’s Groundwater Replenishment System (GWRS) pipeline, which is located a few feet behind the top of the western river embankment slope. Based on our review of the Master Plan (PACE, 2023), the proposed water surface elevations of the south and north impoundment structures will be 145 and 154 feet above the mean sea level (MSL), respectively. We understand that the impoundment structures will consist of a reinforced concrete slab with cutoff walls to prevent scour.

The proposed modifications to the Santa Ana River embankment slopes include constructing stepped and terraced embankments to create seating and landscape planters and may include rebuilding portions of the embankments at slope ratios of 2:1 (horizontal to vertical) in the majority of areas. Slope ratios of 1.5:1 (horizontal to vertical) will be required in certain areas depending on space limitations. Soil cement mixing is being considered to increase the stability of the embankment slopes where needed, which will involve mechanical mixing of cement with the onsite soils. Creation of the river impoundment will also necessitate new improvements where Collins Channel discharges into the Santa Ana River to mitigate the impounded water from extending into the channel. In addition, we anticipate that pump stations, drop structures, and grade control structures will be constructed as part of this project. Other miscellaneous improvements consist of landscaping, public art, a kayak launch, an overlook, and decorative stone rip rap.

The project will also include constructing a new bicycle and pedestrian bridge that will span the Santa Ana River north of Katella Avenue. Based on our review of the drawings for the pedestrian bridge (Parsons, 2023), the bridge will be approximately 376 feet long and supported on two abutments and three bents. We anticipate that steel HP piles will be used for the bridge foundations. The short term (local) and long term (degradation and contraction) scour depths at the bents are estimated to be approximately 7.7 and 11.9 feet, respectively. Scour is not anticipated at the abutments.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 3 Other active transportation improvements for the project include extensions of the Santa Ana River Trail to connect to the Anaheim Coves trail on the west river embankment, providing trail undercrossings below the existing railroad tracks, continuing the Santa Ana River Trail on the east bank of the river between Katella Avenue and Orangewood Avenue, and widening or creating separate bicycle and pedestrian trails along selected areas of the existing Santa Ana River Trail.

It is also our understanding that the Santa Ana River Trail will be widened by approximately 20 feet at the north abutment of California State Route 57 over a span of approximately 350 feet. An approximately 10-foot-high retaining wall will be constructed at the abutment. We anticipate that the retaining wall will be braced with tieback anchors. 4 PREVIOUS GEOTECHNICAL STUDIES
Previous studies performed within the site vicinity include a geotechnical exploration by Ninyo & Moore for the Burris Basin Groundwater Replenishment System Turnout Project in 2021, Harrington Geotechnical Engineering, Inc., (HGE) for the Anaheim River Walk Project and Angels Stadium Master Plan in 2021 and 2020, NMG Geotechnical, Inc., (NMG) for the ocV!be MixedUse Community and Live Entertainment Redevelopment Project in 2020, Earth Mechanics, Inc. (EMI) for the Orangewood Avenue Bridge over Santa Ana River (Widening) in 2019, Langan in 2019 for the Honda Center Parking Structures A through D, Diaz Yourman & Associates (DYA) for the Anaheim Regional Transportation Intermodal Center in 2010, Kleinfelder for the Artic Phase 1 Project in 2009, California Department of Transportation (Caltrans) for the Santa Ana River Bridge in 1976, and the Orange County Road Department for the Ball Road Bridge Across Santa Ana River in 1967. Several of these consultant logs were included in the appendices of the referenced NMG report (2021). Additionally, NMG installed three monitoring wells in the project vicinity as part of the ocV!be Project in 2023 to monitor groundwater levels. We also reviewed our previous reports for Orange County Water District’s Burris and Lincoln Basins Reconfiguration Project (Ninyo & Moore, 2009) and the Five Coves Lincoln Basins Bypass Pipeline Project (Ninyo & Moore, 2010) that included subsurface exploration in the Santa Ana River area located upstream from the OC River Walk Project.

Logs of the relevant exploratory borings, monitoring wells, and cone penetration test (CPT) soundings that are relatively close to the site are included in Appendix A and the locations are shown on Figure 3. The results of the laboratory testing from the previous borings are included in Appendix B.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 4 5 GEOLOGY AND SUBSURFACE CONDITIONS

5.1 Regional Geology
The subject site is located within the southerly portion of the Los Angeles Basin, which is included in the Peninsular Ranges Geomorphic Province (Norris and Webb, 1990). The Los Angeles Basin has been divided into four structural blocks, which are generally bounded by prominent fault systems, and includes the Northwestern Block, the Southwestern Block, the Central Block, and the Northeastern block. The site is located within the Central Block, which is bordered on the west by the Newport-Inglewood fault, on the east by the Whittier-Elsinore fault, on the north by the Malibu Coast-Santa Monica-Raymond fault, and on the south by the San Joaquin Hills and the Santa Ana Mountains. The Central Block is characterized by thick sequences of alluvium overlying basement rocks at depth. Basement rocks exposed in some oil wells along the margins of the Central Block consist of sedimentary Jurassic-age rocks, late Cretaceous-age plutonic rocks, and late Cretaceous to Pleistocene-age sedimentary rocks. Regional geologic mapping indicates that the project area is underlain by Holocene-age alluvial wash and fan deposits generally consisting of gravel, sand, and silt (Morton and Miller, 2006). A map of the regional geology is presented on Figure 4. The Holocene-age alluvial sediments have an estimated thickness of approximately 110 to 130 feet (Sprotte et al., 1980).

5.2 Site Geology
Based on our experience and our review of previous subsurface exploration performed within the project site vicinity, the subsurface stratigraphy of the site generally consists of artificial fill underlain by alluvium. Artificial fill materials were variable and generally consisted of sand, sand with silt, silty sand, sandy silt, silt, clayey silt, and silty clay with varying densities and consistencies. The alluvium was comprised of coarse to fine sediments ranging from silty sand, sand with silt, sand, gravelly sand, silty gravel, clayey gravel, and sandy gravel, with scattered cobbles, and clay, silty clay, clayey silt, silt, and sandy silt. The materials were generally observed to be moist to wet with consistencies that ranged from very loose to very dense in the granular non-plastic soils and very soft to hard in the fine plastic soils. As described, the soils comprising the existing fill and alluvial deposits can vary significantly both laterally and with depth. Therefore, significant variation in the soil stratigraphy observed in previous explorations necessitates conducting a site-specific exploratory program. The locations of the proposed borings are shown on Figures 2 and 3. Our interpretation of the subsurface conditions based on existing data in the project vicinity is shown on Cross Section A-A’ (Figure 5).

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 5 6 GROUNDWATER
During the previous geotechnical evaluations within the project area, groundwater was encountered during drilling at depths ranging from approximately 3 to 58 feet below the ground surface. It should be noted that groundwater was not encountered in all of the borings. The groundwater depth observed at the time of drilling is not considered a stabilized groundwater condition and may vary from the recorded level. Regional maps indicate that the historic high depth to groundwater at the project site is approximately 10 to 20 feet below the ground surface (California Division of Mines and Geology [CDMG], 1997a, 1997b). The historic depth to shallow groundwater is approximately 10 feet deep along the river and becomes deeper to the east and west, beyond the river embankment.

The depth to groundwater across the project site will highly depend on the water levels in the Santa Ana River. Based on our review of the Master Plan (PACE, 2023), the proposed water surface elevations of the south and north impoundment structures will be 145 and 154 feet above the MSL, respectively. Fluctuations in groundwater levels will occur due to variations in precipitation, ground surface topography, subsurface stratification, irrigation, groundwater pumping, and other factors that may not have been evident at the time of our evaluation.

NMG installed three monitoring wells (GW-1 through GW-3) in the project vicinity as part of the ocV!be Project in 2023 to monitor groundwater levels. Table 1 below summarizes the depth to groundwater measured in the monitoring wells and the corresponding elevations. Groundwater measurements were collected over the course of an approximate calendar year from February 3, 2023, to February 29, 2024.

Table 1 – Groundwater Levels in Monitoring Wells
Monitoring Well GW-1 GW-2 GW-3
Surface Elevation
(feet above MSL) 175.0 162.2 168.3
Date of
Measurement
Depth
(feet)
Elevation
(feet above MSL)
Depth
(feet)
Elevation
(feet above MSL)
Depth
(feet)
Elevation
(feet above MSL)
02/03/2023 26.6 148.4 15.0 147.2 35.5 132.8
03/09/2023 26.4 148.6 14.9 147.3 33.7 134.6
04/17/2023 25.9 149.1 14.3 147.9 32.7 135.6
05/18/2023 25.6 149.4 14.2 148.0 32.4 135.9
06/28/2023 25.6 149.4 14.2 148.0 32.1 136.2
07/17/2023 32.5 142.5 25.8 136.4 32.6 135.7
08/10/2023 34.7 140.3 29.4 132.8 34.1 134.2
09/21/2023 26.7 148.3 14.9 147.3 34.9 133.4
10/25/2023 25.9 149.1 14.4 147.8 33.1 135.2
11/29/2023 26.0 149.0 14.9 147.3 32.3 136.0
12/29/2023 26.0 149.0 14.9 147.3 32.1 136.2
01/29/2024 25.8 149.2 14.8 147.4 31.9 136.4
02/29/2024 25.4 149.6 14.8 147.4 31.2 137.2
Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 6 7 FLOOD HAZARDS
Based on our review of flood insurance rate maps for the project area (Federal Emergency Management Agency [FEMA], 2009), the Santa Ana River is located in a special flood hazard area (Zone A) subject to inundation by the 1 percent annual chance flood (100-year flood). Zone A includes areas to be protected from a 100-year flood by the Federal Flood Protection System under construction at the time of publication of the FEMA map (1 percent annual chance flood discharge contained in the channel); no base flood elevations are given. 8 FAULTING AND SEISMICITY
The site is in a seismically active area, as is the majority of southern California, and the potential for strong ground motion in the project area is considered significant during the design life of the proposed project. Figure 6 shows the approximate site location relative to the major faults in the region. The site is not located within a State of California Earthquake Fault Zone (EFZ) (formerly known as an Alquist-Priolo Special Studies Zone) (California Geological Survey [CGS], 2018).

The nearest mapped active fault to the site is the Peralta Hills fault located approximately 3 miles north of the site (United States Geological Survey [USGS], 2024a).

The principal seismic hazards evaluated at the subject site are surface fault rupture, ground motion, liquefaction, dynamic settlement, lateral spread, and tsunamis and seiches. A brief description of these principal seismic hazards is discussed in the following sections.

8.1 Surface Fault Rupture
Based on our review of the referenced literature, no active faults are known to cross the project site. Therefore, the probability of damage from surface fault rupture is considered to be low.

However, lurching or cracking of the ground surface as a result of nearby seismic events is possible.

8.2 Strong Ground Motion
Considering the proximity of the site to active faults capable of producing a maximum moment magnitude of 6.0 or more, the project area has a high potential for experiencing strong ground motion. Based on our discussions with the design team, it is our understanding that the proposed pedestrian bridge will be designed in accordance with the Caltrans Seismic Design Criteria (Caltrans, 2019a). The average shear wave velocity in the upper 30 meters (100 feet) of the subsurface profile (VS30) at the site is estimated to be approximately 228 meters per second (i.e., 748 feet per second) based on our review of CGS’s shear wave velocity map (2015). This corresponds to EMI’s estimated VS30 (235 meters per second [771 feet per second]) based on Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 7 blow count correlations from their borings for the Orangewood Avenue Bridge (2020). Based on the Caltrans Acceleration Response Spectra (ARS) online web tool (Caltrans, 2024b) and using a VS30 of 228 meters per second for the site, a mean magnitude of 6.58 and a peak ground acceleration (PGA) of 0.51g is appropriate for the proposed pedestrian bridge. The design Caltrans ARS curve evaluated for the bridge site is presented on Figure 7.

8.3 Liquefaction and Seismically Induced Settlement
Liquefaction is the phenomenon in which loosely deposited, saturated granular soils (located below the water table) undergo rapid loss of shear strength due to development of excess pore pressure during strong earthquake-induced ground shaking. Ground shaking of sufficient duration results in the loss of grain-to-grain contact due to rapid rise in pore water pressure and it eventually causes the soil to behave as a fluid for a short period of time. Liquefaction is known generally to occur in saturated or near-saturated cohesionless soils at depths shallower than 50 feet below the ground surface. Liquefaction is also known to occur in relatively fine-grained soils (i.e., sandy silt and clayey silt) with a plasticity index of less than 7. Factors known to influence liquefaction potential include composition and thickness of soil layers, grain size, relative density, groundwater level, degree of saturation, and both intensity and duration of ground shaking. Based on our review of the State of California Seismic Hazard Zones maps (CDMG, 1998a, 1998b), the project site is located in an area mapped as being potentially susceptible to liquefaction (Figure 8).

Based on the referenced previous studies and our experience in the project area, the relatively loose to medium dense sand and silt layers at variable depths below the groundwater table are expected to be liquefiable during a significant seismic event. As a result of liquefaction, the proposed improvements may be subject to liquefaction-induced dynamic settlement. The amount of soil settlement during a strong seismic event depends on the thickness of the liquefiable layers and the density and/or consistency of the soils. Dynamic settlements associated with liquefaction at the site could vary from approximately 2 to 6 inches (HGE, 2021; NMG, 2020; and EMI, 2019).

8.4 Lateral Spreading
Lateral spreading of the ground surface during an earthquake usually takes place along weak shear zones that have formed within a liquefiable soil layer. Lateral spread has generally been observed to take place in the direction of a free-face (i.e., retaining wall, slope, and channel), but has also been observed to a lesser extent on ground surfaces with very gentle slopes. An empirical model developed by Bartlett and Youd (1995, revised 2002) is typically used to predict the amount of horizontal ground displacement within a site. For sites located in proximity to a freeface, the amount of lateral ground displacement is strongly correlated with the distance of the site Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 8 from the free-face. Other factors such as earthquake magnitude, distance from the earthquake epicenter, thickness of the liquefiable layers, and the fines content and particle sizes of the liquefiable layers also affect the amount of lateral ground displacement. Since the site is located within the free-faces of the Santa Ana River, there is a potential for seismically induced lateral spread at the site. EMI concluded that lateral spreading is not a design concern for the Orangewood Avenue Bridge since the potentially liquefiable thin soil layers are intermittent and discontinuous (2019).

8.5 Tsunamis and Seiches
Tsunamis are long wavelength, seismic, sea waves (long compared to ocean depth) generated by the sudden movements of the ocean floor during submarine earthquakes, landslides, or volcanic activity. Seiches are waves generated in a large, enclosed body of water. The project area is not mapped within an area considered susceptible to tsunami or seiche inundation (California Department of Conservation, 2024). Therefore, damage due to tsunamis or seiches is not a design consideration.
9 SLOPE STABILITY ANALYSES
Slope stability analyses were performed to evaluate the stability of the proposed embankment slopes based on Cross Section A-A’ (north impoundment area). The west side of the cross-section was considered to be more critical. Based on our discussions with PACE, it is our understanding that a majority of the slopes will be constructed at a slope ratio of 2:1 (horizontal to vertical), but some of slopes may need be constructed at a slope ratio of 1.5:1 (horizontal to vertical) depending on space limitations. Soil cement mixing is being considered to increase the stability of the embankment slopes where needed. Our analyses were developed for the empty (dry), full, and rapid drawdown conditions. The analyses involving empty and full water conditions considered static and pseudo-static loading. The rapid drawdown condition was conservatively modeled assuming that the phreatic surface is approximately aligned with the slope surface on the channel side.

Our slope stability analyses were performed using the Morgenstern and Price limit equilibrium option in a two-dimensional stability analysis program, Slope/W (GeoStudio, 2023). The pseudostatic analyses were performed using a coefficient of horizontal ground acceleration of 0.15 as recommended in Special Publication (SP) 117A (California Geological Survey, 2008). In general accordance with the guidelines of SP 117A and the standard of practice, our analyses considered the following design criteria: 1) a factor of safety of 1.5 for the static conditions, 2) a factor of Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 9 safety of 1.1 for the pseudo-static conditions, and 3) a factor of safety of 1.3 for the rapid drawdown condition.

The shear strength parameters used in our stability analyses were selected based on the findings from the previous field and laboratory testing and our experience with these material types. Each of the materials were assigned with homogeneous, isotropic properties and modeled using the Mohr-Coulomb constitutive model. The material properties used in our stability analyses are presented in Table 2.

Table 2 – Material Properties Used in Slope Stability Evaluation Earth Material Unit Weight (pcf) Cohesion (psf) Friction Angle (degree) River Embankment Fill 115 100 32
New Engineered Fill 120 100 32
Alluvium – Sand (Medium Dense) 120 100 32
Alluvium – Sand (Dense) 120 100 34
Alluvium – Clay 120 2,000 0
Soil Cement 130 5,000 0
Notes:
psf – pounds per square feet
Our analyses incorporated the maximum water levels anticipated within the Santa Ana River as discussed in Section 6 of this report. A surface water elevation of 154 feet was considered in the Santa Ana River based on the north impoundment structure for the full and rapid drawdown conditions. The results of our global stability evaluation indicate that the proposed embankment slopes constructed at a slope ratio of 2:1 (horizontal to vertical) will have adequate factors of safety against global instability during empty, full, and rapid-drawdown scenarios under both static and pseudo-static loading conditions. However, we calculated that the embankment slopes placed at a slope ratio of 1.5:1 (horizontal to vertical) will not have adequate factors of safety against global stability during full and rapid-drawdown scenarios under both static and pseudo-static loading conditions. However, our slope stability analyses indicate that if the outer portion of the slope is removed and those materials are replaced with a stabilization fill slope with an approximately 15-foot-wide soil cement zone, the factors of safety will increase to adequate levels. The results of our slope stability analyses are summarized in Table 3 and are presented in Appendix C. We recommend that the stability of the proposed slopes be evaluated in more detail based on the findings from our subsurface evaluation and our review of the grading plans when they are available. Additionally, surcharge loads from existing improvements and surface development areas should be considered in supplemental analyses. Future seepage analyses may also be appropriate during a supplemental design phase to evaluate the effects of impounding water against the proposed embankment slopes and the potential for seepage and piping beneath the impoundment structures.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 10 Table 3 – Summary of Slope Stability Analyses
Analysis
Calculated Factor of Safety
Required Factor of
2:1 Slope Ratio 1.5:1 Slope Ratio Safety 1.5:1 Slope Ratio Soil Cement
Empty – Static 1.88 1.51 1.60 1.5
Empty – Pseudo-static 1.37 1.16 1.22 1.1
Full – Static 1.75 1.45 1.51 1.5
Full – Pseudo-static 1.23 1.08 1.11 1.1
Rapid Drawdown 1.52 1.23 1.32 1.3
10 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS
The purpose of this study was to perform a preliminary evaluation of the soil, geologic, and groundwater conditions in the area of the proposed OC River Walk Project. The results from our preliminary geotechnical evaluation will be used to assist the USACE in providing the project with Section 404 and 408 permission and approving our Drilling Program Plan. Based on the preliminary evaluation, it is Ninyo & Moore’s opinion that the project is feasible from a geotechnical perspective. Although there were several previous borings and CPT soundings performed in the project area, additional borings will be appropriate in areas with insufficient data (i.e., the impoundment structures, the east side of the Santa Ana River, and the proposed pedestrian bridge). Updated design and construction recommendations for the project will be provided in an updated geotechnical evaluation report based on the findings from our subsurface evaluation once our Drilling Program Plan is approved. A summary of our preliminary conclusions is presented below:
• The project area is generally anticipated to be underlain by artificial fill and alluvium consisting of moist to wet, very loose to very dense silty sand, sand with silt, sand, gravelly sand, silty gravel, clayey gravel, and sandy gravel with scattered cobbles, and very soft to hard clay, silty clay, clayey silt, silt, and sandy silt. A significant variation in the soil stratigraphy was observed in the previous explorations, which accentuates the need for conducting a site-specific exploratory program.
• In order to provide suitable support for the planned improvements (impoundment structures, pump stations, retaining walls, drop structures, and grade control structures), remedial excavation and recompaction of loose soil beneath the foundation zones should be performed. The old fills on site are anticipated to have variable degrees of compaction and are not considered suitable for support of the new improvements. We anticipate that the excavations within the Santa Ana River Channel will extend below the potential scour depth. • Excavations during site grading should be feasible with earthmoving equipment in good working order. We anticipate that the existing fill and alluvial materials may be reused as compacted fill. Depending on seasonal variability and groundwater levels, some of the soils may have relatively high moisture contents and may involve drying or blending with drier materials in order to be used as compacted fill.
• Groundwater was encountered in some of the previous borings performed in the project area at depths ranging from approximately 3 to 58 feet below the ground surface. The historic high groundwater is reported at depths ranging from approximately 10 to 20 feet below the ground Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 11 surface. Excavations for the impoundment structures that extend below groundwater may involve construction dewatering depending on the depths and seasonal conditions.

Excavations for cast-in-drilled-hole (CIDH) piles may also encounter groundwater.

Fluctuations in the groundwater level are anticipated to occur as a result of the proposed water impoundment as well as variations in seasonal precipitation, irrigation practices, groundwater pumping, and other factors.
• The proposed water surface elevations of the south and north impoundment structures will be 145 and 154 feet above MSL, respectively. Based on these elevations and the elevations of the river bottom near the proposed impoundment structures, the impounded water will be on the order of 8 to 10 feet deep adjacent to the impoundment structures. The surface water level in the river is anticipated to have an impact on the groundwater level; therefore, impounding water in the river is anticipated to result in raising the groundwater elevations in the embankment slope areas adjacent to the river. Based on the generally granular nature of the alluvium, we anticipate infiltration of the impounded surface water into the subsurface soils predominantly in the vertical direction. However, the presence of less permeable silt and clay layers at depth could create a perched groundwater condition that could result in shallower depths to groundwater extending beyond the river embankment slopes. Additional groundwater monitoring during and after high river flow events should be considered to evaluate the change in groundwater elevations and the distance to which the river surface water elevation may influence the groundwater level beyond the river embankment slopes. • The site is located within a “Zone A” designated flood area (FEMA, 2009). The lower terrace path, and portions of the middle terrace path and amphitheater seating are planned at elevations that are lower than the 100-year flood level. Proposed structural improvements below the 100-year flood zone should be designed to mitigate the potential for scour and erosion from the 100-year flood event.
• Should a 100-year flood event occur, river sediments may be deposited on the lower and middle terraces, and amphitheater seating areas. Periodic maintenance to clean-up and remove flood deposits should be planned for.
• On-site soils should be considered as Type C soils in accordance with Occupational Safety and Health Administration (OSHA) soil classifications. Sandy soils may be prone to caving during earthwork operations. Excavations that extend below groundwater or where temporary slopes are not feasible will involve shoring for safety and protection to existing improvements. • The results of our stability analyses indicate that adequate factors of safety will be maintained for design slopes constructed at a slope ratio of 2:1 (horizontal to vertical) under static, pseudo-static, and rapid drawdown conditions. Proposed 1.5:1 (horizontal to vertical) slopes will not have adequate factors of safety against global stability during fill and rapid-drawdown scenarios. As such, proposed 1.5:1 (horizontal to vertical) slopes will need to be reconstructed as 15-foot-wide stabilization fill slopes with soil cement to increase the factors of safety. • The subject site is not located within a State of California Earthquake Fault Zone (AlquistPriolo Special Studies Zone). The probability of surface fault rupture or secondary ground deformation is considered low at the site.
• The site is mapped within a State of California Seismic Hazards Zone as being potentially liquefiable (CDMG, 1998a, 1998b). Our evaluation indicates that the relatively loose to medium dense granular soil layers occurring below the historic high groundwater level are susceptible to liquefaction during the design seismic event. Liquefaction-induced ground settlement were estimated to be on the order of approximately 2 to 6 inches by previous geotechnical consultants. A site-specific exploratory program will be needed to more accurately quantify the depths to which the subsurface soils are prone to liquefaction at the project site and the dynamic settlement magnitudes at the proposed improvements. • The site is not located in an area considered susceptible to landsliding, tsunamis, or seiches.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 12 • Based on the previous laboratory test results in the project vicinity, the near-surface site soils can be classified as non-corrosive based on the California Department of Transportation (Caltrans, 2021b) corrosion guidelines.

As mentioned above, a detailed geotechnical evaluation including subsurface exploration should be performed to develop site-specific information and develop appropriate geotechnical recommendations for the design and construction of the OC River Walk Project. This will involve performing additional borings to evaluate liquefaction, foundations, and slope stability in more detail. The locations of the proposed borings are presented on Figures 2 and 3. Preliminary design recommendations are presented below.

10.1 Earthwork
We anticipate that earthwork at the site will include site clearing, foundation excavations for the pedestrian bridge, subgrade preparation for structures, retaining wall backfill, slope construction along the Santa Ana River, and relatively shallow grading for the new trails and bikeways.

Earthwork operations should be performed in accordance with the requirements of applicable governing agencies and the recommendations presented in the following sections.

10.1.1 Construction Plan Review and Pre-Construction Conference We recommend that grading and foundation plans be submitted to Ninyo & Moore for review to check for conformance to the recommendations provided in this preliminary report and our future report. We further recommend that a pre-construction conference be held in order to discuss the grading recommendations presented in our reports. The owner and/or their representative, the governing agencies’ representatives, the civil engineer, Ninyo & Moore, and the contractor should be in attendance to discuss the work plan, project schedule, and earthwork requirements.

10.1.2 Site Clearing
Prior to commencing earthwork operations, the site should be cleared of surface obstructions, abandoned utilities (if present), debris, vegetation, as well as surface soils containing organic materials. Existing utilities to remain in place should be located and then re-routed or protected from damage by construction activities. The contractor may need to implement a documentation and instrumentation program near certain improvements during construction.

Obstructions that extend below the finished grade, if any, should be removed and the resulting holes filled with compacted soil. The materials generated from the clearing operations should be removed from the site and disposed at a legal dump site.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 13

10.1.3 Excavation Characteristics
Based on the previous field exploration, we anticipate that excavations within the existing fill and alluvial materials at the site may be accomplished with earthmoving equipment in good working condition. The soils generally consisted moist to wet, very loose to very dense silty sand, sand with silt, sand, gravelly sand, silty gravel, clayey gravel, and sandy gravel, with scattered cobbles, and very soft to hard clay, silty clay, clayey silt, silt, and sandy silt.

Contractors should make their own independent evaluation of the excavatability of the onsite materials prior to submitting their bids.

10.1.4 Remedial Grading for Improvements on Shallow Foundations In order to provide suitable support for the planned improvements (impoundment structures, pump stations, retaining walls, amphitheater seating walls, drop structures, and grade control structures that will be placed on shallow foundations, remedial grading consisting of the excavation and recompaction of the existing undocumented fill and/or loose natural materials is appropriate. We recommend that excavation and recompaction extend to the depth of the undocumented fill to expose firm and unyielding alluvium or to a depth that will provide 2 to 3 feet of compacted fill below the bottom of the proposed foundations, whichever is deeper.

For improvements constructed within the Santa Ana River channel, the base of the improvements should extend approximately 2 feet below the potential scour depth unless the improvements are designed to prevent scour. We understand that the impoundment structures will consist of a reinforced concrete slab with cutoff walls to prevent scour.

The limits of excavation should extend laterally 2 to 3 feet beyond the outside edges of the foundation or a distance equal to the depth of the excavation, whichever is further. Relatively competent alluvial materials should be exposed at the excavation bottoms. If the remedial grading bottom is unstable under heavy equipment loads, additional excavation may be needed to stabilize the bottom. Stabilizing the bottom may include excavating an additional 1 to 2 feet and replacing the material with aggregate base or crushed rock wrapped in filter fabric. The extent of the removals should be evaluated by Ninyo & Moore at the time of construction.

The removal and recompaction work should consist of 1) excavating to the depths discussed above, 2) scarifying, moisture-conditioning, and compacting the exposed subgrade soils to a depth of 8 inches or more, and 3) placing the excavated materials back as compacted fill.

The fill soils should be moisture-conditioned generally above the optimum moisture content Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 14 and should be compacted to a relative compaction of 90 percent as evaluated by the ASTM International (ASTM) test method D 1557.

10.1.5 Treatment of Near-Surface Soils for the Santa Ana River Trail Prior to placement of the new structural pavement sections for the Santa Ana River Trail, the subgrade soils should be prepared appropriately. In areas of the proposed pavement sections, concrete walkways, bicycle paths, and other hardscape improvements, we recommend that the top 12 inches of subgrade soils be scarified and compacted to approximately 90 percent or more at a moisture content slightly above the laboratory optimum as evaluated by ASTM D 1557.

10.1.6 Temporary Excavations and Shoring
We recommend that trenches and excavations be designed and constructed in accordance with the OSHA regulations. These regulations provide shoring design parameters for excavations and trenches up to 20 feet deep based on the soil types encountered. Although not anticipated, if trenches over 20 feet deep are needed, they should be designed by the contractor’s engineer based on site-specific geotechnical analyses.

We anticipate that the majority of the excavations at the site will be laid-back using temporary slopes. Some of the near-surface soils at the site are granular with little fines content and may be subject to caving and are, therefore, not anticipated to be stable in vertical excavations. In addition, bedding materials for existing pipelines, if encountered, may also be prone to caving. Depending on seasonal precipitation, some soft ground may be present at the ground surface resulting in unstable conditions for equipment and/or temporary excavations. Based on the granular nature of the near-surface site soils, excavations should be sloped at an inclination no steeper than 1.5:1 (horizontal to vertical). For planning purposes, we recommend that the on-site soils be considered as Type C soil in accordance with the OSHA soil classification.

Where slopes cannot be laid back, shoring will be appropriate. If there will be excavations that extend below the springline of the GWRS pipeline, such as to excavate a temporary backcut for a 1.5:1 (horizontal to vertical) soil cement stabilization fill slope or for excavations for the pedestrian bridge western abutment, shoring may be needed to support the GWRS pipeline. Where shoring systems are used for site excavations, they should be designed for the anticipated soil conditions using the lateral earth pressure values presented on Figures 9 and 10 for braced and cantilevered excavations below groundwater, respectively. The recommended design pressures are based on the assumption that the shoring system will Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 15 be constructed without raising the ground surface elevation behind the shored sidewalls of the excavation, that there will be no surcharge loads, such as soil stockpiles and construction materials, and that no loads will act above a 1:1 (horizontal to vertical) plane ascending from the base of the shoring system. For a shoring system subjected to the above-mentioned surcharge loads, the contractor should include the effect of these loads on the lateral earth pressures acting on the shored walls.

We anticipate that settlement of the ground surface will occur behind the shored excavations.

The amount of settlement depends heavily on the type of shoring system, the contractor’s workmanship, and soil conditions. To reduce the potential for distress to adjacent improvements, we recommend that the shoring system be designed to limit the ground settlement behind the shoring system to 0.5 inch or less. Possible causes of settlement that should be addressed include settlement during installation of the shoring elements, excavation for structure construction, construction vibrations, and removal of the support system. We recommend that shoring installation be evaluated carefully by the contractor prior to construction.

The contractor should retain a qualified and experienced engineer to design the shoring system. The shoring parameters presented in this report are minimum requirements, and the contractor should evaluate the adequacy of these parameters and make the appropriate modifications for their design. We recommend that the contractor take appropriate measures to protect workers. OSHA requirements pertaining to worker safety should be observed.

10.1.7 Construction Dewatering
If applicable, dewatering will be involved for excavations that extend below groundwater so that work can be performed in a relatively dry condition. Lowering the water table results in an increase in effective stresses and may induce settlement of soils beneath existing improvements. Dewatering systems should be designed to reduce the withdrawal of groundwater outside of the planned excavations. This may be achieved with a combination of shoring systems that act as cut-off walls and pumping out groundwater from within the shored excavations. Disposal of groundwater should be performed in accordance with guidelines of the Regional Water Quality Control Board and Orange County Sanitation District.

10.1.8 Slopes
We recommend that new fill slopes be constructed at slope ratios of 2:1 (horizontal to vertical) or flatter. Fill slopes constructed at 2:1 (horizontal to vertical) or flatter are anticipated to be Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 16 stable. Based on the findings from our slope stability analyses, we recommend that soil cement be used on fill slopes steeper than 2:1 (horizontal to vertical). New fill slopes should be constructed with a keyway that is approximately 15 feet wide and should extend 2 feet or more into competent alluvial soils (Figure 11). As shown on Figure 11, the soil for the fill key should be removed within a 1:1 (horizontal to vertical) projection from the proposed toe-ofslope. After the fill key is constructed, benching should be performed to remove loose surficial soils associated with the existing slopes. For the 1.5:1 (horizontal to vertical) soil cement stabilization fill slopes, the 15-foot-wide soil cement zone should be maintained from the keyway up to the top of the slope.

The need for keyway backdrains should be evaluated during grading and will depend on the soils that are used to construct the slope as well as the soils that comprise the existing slopes that the new fill slopes will be benched into. In general, if the new fill material that will be placed to construct the new slopes is similar to the soils that comprise the existing slopes, a keyway backdrain should not be needed. However, if the soils are significantly different, such as the new fill having a significantly higher percentage of fines than the existing slope soils, this condition could result in a buildup of hydrostatic pressure at the contact between the new fill and the existing fill. In this condition, installation of a keyway backdrain would be appropriate. A representative of Ninyo & Moore should observe the keyway construction and provide recommendations for subdrain systems, as appropriate.

Fill slopes should be constructed in a manner (e.g., overfilling and cutting to grade) such that the recommended degree of compaction is achieved to the finished slope face. Appropriate drainage devices should be provided to direct surface runoff away from slope faces. The project plans and specifications should contain design features and construction requirements to reduce the potential for erosion of the on-site soils both during and after construction. We recommend that routine slope maintenance be performed including repair of rills and other slope erosion features that may occur.

10.1.9 Fill Material
In general, the on-site soils should be suitable for use as embankment fill and trench backfill provided that they are free of trash, debris, roots, vegetation, deleterious materials, and contamination. Fill should generally be free of rocks or lumps of material in excess of 4 inches in diameter. Rocks or hard lumps larger than approximately 4 inches in diameter should be broken into smaller pieces or should be removed from the site. On-site soils used as fill will involve moisture-conditioning to achieve the appropriate moisture content for compaction.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 17 Recommendations for the percent cement content that will need to be added to the on-site soils in order to achieve the desired strength parameters for the 1.5:1 (horizontal to vertical) stabilization fill slopes will be provided in our forthcoming report. Varying amounts of cement will be added to representative samples of the on-site soils to evaluate the corresponding material strength. We will also evaluate the gradation, unit weight, and moisture content of the samples. Proportioning of the mix designs should be based on procedures outlined in the Federal Highway Administration (FHWA) Design Manual: Deep Mixing for Embankment and Foundation Support (2013). A shear strength of 5,000 psf (approximately 35 pounds per square inch [psi]) was considered for the soil cement in our slope stability analyses. For preliminary planning purposes, a cement content of 5 to 10 percent is anticipated.

Fill used as backfill behind retaining walls and other structure backfill should consist of freedraining, granular, non-expansive soil that conforms with the latest edition of “Greenbook” Standard Specifications for Public Works Construction for structure backfill. “Non-expansive” can be defined as soils having an expansion index (EI) of 20 or less in accordance with ASTM D 4829.

Imported materials, if used, should consist of clean, non-expansive, granular material, which conforms to the “Greenbook” for structure backfill. The imported materials should also meet the Caltrans (2021b) criteria for non-corrosive soils (i.e., soils having a minimum resistivity greater than 1,500 ohm-centimeters, a chloride concentration less than 500 parts per million [ppm], a sulfate concentration of less than 0.15 percent (1,500 ppm), and a pH value greater than 5.5). Import materials for use as fill should be evaluated by the geotechnical consultant prior to importing. The contractor should be responsible for the uniformity of import material brought to the site.

10.1.10 Fill Placement and Compaction
Fill material, including trench backfill, should be moisture-conditioned and compacted in horizontal lifts to a relative compaction of 90 percent or more as evaluated by ASTM D 1557.

Fill material should be moisture-conditioned to slightly above the laboratory optimum moisture content. The lift thickness for fill soils will depend on the type of compaction equipment used but generally should not exceed 8 inches in loose thickness. Special care should be exercised to avoid damaging pipes during compaction of trench backfill. Placement and compaction of the fill soils should be in general accordance with local grading ordinances and good construction practice. Specific recommendations for placement and compaction of soil cement will be provided in our future geotechnical report based on our laboratory testing of the on-site soils with varying cement contents and our engineering analyses.

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10.1.11 Pipe Bedding
We recommend that pipelines be supported on 6 inches or more of granular bedding material such as sand with a sand equivalent (SE) value of 30 or more. Bedding material should be placed and compacted around the pipe, and 12 inches or more above the top of the pipe in accordance with the current “Greenbook” Standard Specifications for Public Works. Special care should be taken not to allow voids beneath and around the pipe. Bedding material and compaction requirements should be in accordance with the recommendations of this report, the project specifications, and applicable requirements of the appropriate agencies.

10.1.12 Modulus of Soil Reaction
The modulus of soil reaction is used to characterize the stiffness of soil backfill placed on the sides of buried flexible pipelines for the purpose of evaluating lateral deflection caused by the weight of the backfill above the pipe. We recommend that a modulus of soil reaction of 1,000 psi be used for design, provided that granular bedding material is placed adjacent to the pipe, as recommended in this report.

10.2 Foundations
Based on our discussions with PACE, it is our understanding that steel HP piles will be used for the pedestrian bridge foundations. Alternatively, if construction vibrations or noise are issues at the site, cast-in-drilled-hole (CIDH) piles may also be considered for the pedestrian bridge.

Shallow foundations, including spread footings and mat foundations, may be used for the proposed impoundment structures, pump stations, retaining walls, drop structures, and grade control structures. Foundations should be designed in accordance with structural considerations and the following recommendations. In addition, requirements of the appropriate governing jurisdictions and applicable building codes should be considered in the design of the structures.

Details regarding the foundations were not available for our review at the time of this evaluation.

We made numerous assumptions in our foundation analyses including pile type, pile size, pile cutoff elevation, soil parameters, depth to liquefaction zone, etc. Our preliminary foundation recommendations will need to be updated based on the findings from our site-specific subsurface evaluation.

10.2.1 Pile Design Considerations
The proposed pedestrian bridge may be supported on driven steel HP piles or cast-in-drilledhole (CIDH) piles. We analyzed both HP 14x89 steel piles and 24-inch-diameter CIDH piles for preliminary planning purposes. The piles should extend below the liquefaction zone and be advanced into very dense alluvium. Negative skin friction caused by liquefaction and Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 19 subsequent settlement of layers above the liquefaction zone was considered in our pile capacity analyses. It is also our understanding that the bent piles are susceptible to up to approximately 11.9 feet of long-term scour. The axial capacity for the piles was analyzed using AllPile Version 7.21e (CivilTech, 2016) computer software. Soil strength parameters were estimated using existing data from sampler blow counts and laboratory test results reported in previous geotechnical evaluations at nearby sites. Axial capacities for the steel HP piles were based on side friction resistance and end bearing. End bearing was not included in our analysis for the CIDH piles. We also considered the scenario where side friction in the upper 11.9 feet was neglected for the bent piles due to scour. Plots of the depth versus ultimate axial capacity for the piles at the abutments and bents under both the static and dynamic (liquefaction) conditions and the piles at the bents due to scour are presented in Appendix D.

Per the 2022 CBC, we recommend that a factor of safety of 2.0 be used for the allowable axial capacity in compression and a factor of safety of 3.0 be used for the allowable axial capacity in uplift/tension. If the measures outlined in this report are implemented effectively, the total settlement of the CIDH piles is anticipated to be 0.5-inch or less, provided that the pile bearing materials are not significantly disturbed during construction. These estimates are based on the soil conditions observed in the previous exploratory borings, and our experience with similar geologic materials. The pile capacities presented in Appendix D should be revised, as appropriate, after additional subsurface data are obtained. Lateral pile capacities should also be analyzed when the details of the proposed foundations and the loading conditions are available. To reduce the potential for group action of the pile foundations, we recommend that piles be spaced no closer than three times the pile diameter (center-tocenter spacing) to attain the estimated axial capacity.

10.2.2 Driven Pile Construction Considerations
We anticipate that high tensile stresses will be generated in the piles during driving when the piles penetrate through the looser sand layers and clay layers into the dense sand and gravel layers. The tensile stress may be high enough to damage the pile. If it is difficult to advance the piles in the dense sand and gravel layers, consideration should be given to pre-drilling the pile locations with an auger having a diameter that is 25 percent smaller than the width of the pile. The pre-drilled hole depth should be evaluated during construction.

Pre-drilled holes and piles should be installed as closely as possible to specified limits of vertical and horizontal alignment. The pile should not be out of plumb by more than 2 percent Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 20 over the length of the pile. Further, the top of the pile should be within 3 inches of the design location.

Prior to installing production piles, we recommend that a test program of an indicator pile be performed. This should consist of driving one pile as an indicator pile. The indicator pile should be evaluated using a Pile Driving Analyzer and Case Pile Wave Analysis Program to evaluate the design, to evaluate the appropriate size of hammer, and to establish refusal criteria for the project. The indicator pile should be 10 feet longer than the preliminary design length and should be installed to allow cut-off at any length. Upon completion of the indicator pile program, Ninyo & Moore can provide pile driving recommendations for the project.

The effect of the pile driving operations on structures and improvements within approximately 50 feet of the site should be evaluated. Vibration monitoring should be performed during the indicator pile program and during installation of production piles to evaluate peak particle velocities at adjacent structures and improvements. Ninyo & Moore should review the data as they are obtained.

10.2.3 CIDH Pile Construction Considerations
Our evaluation of the excavation characteristics of the on-site materials is based on the results of the previous exploratory borings and experience with similar materials. The CIDH pile drilling contractor should mobilize equipment of sufficient size and operating capability to achieve the recommended embedment length in the alluvium. The excavation technique chosen by the contractor should not adversely affect the quality or strength of the shaft side or end bearing materials.

Due to the nature of the soils, caving in the underlying materials should be anticipated during drilling/installation of CIDH piles. The contractor should be prepared to handle such conditions by adjusting drilling methods and rates, using drilling mud, and/or using temporary casing. If casing is used, the casing should be withdrawn gradually during removal. Drilling mud should be collected as it is pushed out of the drilled hole with concrete placed using the tremie method. Groundwater was encountered in the previous borings and should be expected to be encountered during drilling. The contractor should be prepared to advance the CIDH piles under such conditions.

The concrete should be placed in the annular space between the rebar cage and the drillhole surface using the tremie method. Concrete utilized in the CIDH piles should be a fluid mix with sufficient slump so that it will fill the void between the rebar cage and the drill-hole Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 21 wall. The contractor should take care to reduce enlargement of the excavation at the tops of the CIDH piles, which could result in mushrooming of the CIDH pile top.

CIDH pile holes should be cleaned prior to placement of concrete. Care should be taken to check that the soils at the CIDH pile bottom have not been disturbed. The successful advancement of drill-holes for the construction of CIDH piles will depend largely on the suitability of the drilling equipment and the skill of the operator. The drilled foundation contractor should try to reduce the time during which the excavation remains open. The contractor should schedule the sequence of operations so that each excavation can be finished, the rebar cage placed, and the concrete poured within the same work day. CIDH pile excavations should not be left open overnight. In case of delay in placing concrete within the drill hole due to equipment breakdown or other unforeseen circumstances, casing may be used to protect the integrity of the hole.

The contractor should not place CIDH piles adjacent to each other until the first one is set.

The installation of CIDH piles should be scheduled to allow the concrete in adjacent shafts to set before drilling the next shaft. CIDH piles spaced closer than about three shaft diameters (clear spacing) should be placed on alternate days.

The CIDH pile installation should be observed by the project geotechnical consultant to check that, among other things: 1) subsurface conditions are as anticipated from the borings, 2) the CIDH piles are constructed to the specified size and penetration, 3) the CIDH pile bottom is clean and competent, 4) CIDH piles are within the allowable tolerances for plumbness, and 5) reinforcements are placed per project specifications. These items are fundamental to the installation and behavior of the CIDH piles. Furthermore, we recommend the following for the installation of CIDH piles.
• The clear spacing between the rebar cage and the drill-hole surface should be three times the maximum size of the coarse aggregate used in the concrete. • Centralizers should be installed to keep the rebar cage positioned per project specifications.
• If casing is used, a sufficient head of concrete that fills the casing should be used before pulling the casing.

10.2.4 Pole Foundations
Light poles, awnings, signs, and flag poles typically impose relatively light axial loads on pile foundations and the pile dimensions will generally be controlled by the lateral load demand.

We recommend that the pole foundations have a diameter of 18 inches or more and an Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 22 embedment depth of 10 feet or more into competent soils. We recommend that pole foundations be designed for an allowable side friction of 130 psf for downward axial loads and an allowable resistance of 90 psf for uplift capacity. The lateral capacity of the drilled piers may be evaluated using a lateral bearing pressure of 150 psf per foot of depth, up to a value of 1,500 psf per foot of depth. The passive resistance may be considered to act on an area equal to the product of the effective width (two times the pier diameter) and the embedded length of the pier. The footing dimensions (i.e., diameter and embedment) should be evaluated by the project structural engineer. Foundations for light standards, roadside signs, and overhead signs should be designed in accordance with the Caltrans Standard Plans (Caltrans, 2022a).

10.2.5 Spread Footings and Mats
Based on Ninyo & Moore’s understanding of the proposed construction, it is anticipated that the proposed impoundment structures, pump stations, retaining walls, drop structures, and grade control structures may be supported on spread footings or mats. The footings should bear on dense native soils or compacted fill material prepared in accordance with the recommendations presented in the Earthwork section of this report.

For preliminary planning purposes, shallow spread footings may be designed using a net allowable bearing capacity of 2,000 psf and should be founded approximately 18 inches or more below grade. Continuous footings should have a width of 2 feet or more. Isolated pad footings should have a width of 3 feet or more. Spread footings should be reinforced in accordance with the recommendations of the structural engineer. Total and differential settlement for footings under static load are estimated to be less than approximately 1 inch and 0.5-inch over a horizontal span of 40 feet, respectively. Mats typically experience some deflection due to loads placed on the mat and the reaction of the soils underlying the mat. On a preliminary basis, a design modulus of subgrade reaction of 50 tons per cubic foot (tcf) may be used for the compacted subgrade soils in evaluating such deflections.

The footings and mats supported on compacted fill or dense native soils may be designed using a coefficient of friction of 0.35, where the total frictional resistance equals the coefficient of friction times the dead load. The footings may be designed using a passive resistance value of 350 psf per foot of depth up to a value of 3,500 psf. The allowable lateral resistance can be taken as the sum of the frictional resistance and passive resistance, provided the passive resistance does not exceed one-half of the total allowable resistance. The net allowable bearing capacity and passive resistance may be increased by one-third when considering loads of short duration such as wind or seismic forces.

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10.2.6 Slabs-On-Grade
Structures supported on shallow footings should have floor slabs designed by the project structural engineer based on the anticipated loading conditions. Additionally, concrete surface finishing may be present on top of the soil cement in certain areas of the project. Building floor slabs should be underlain by compacted fill prepared in accordance with the recommendations presented in the Earthwork section of our report. We recommend that floor slabs be 5 inches thick or more and reinforced in accordance with the recommendations of the structural engineer. The placement of the reinforcement in the slab is vital for satisfactory performance.

The floor slab and foundations should be tied together by extending the slab reinforcement into the footings. The slab should be underlain by a 4-inch-thick capillary break (consisting of either sand or crushed rock) overlain by a polyethylene vapor retarder (with a thickness of 10 mils or more). The steel reinforcements for the floor slab shall be placed on the vapor retarder using chairs, as appropriate. The vapor retarder is recommended in areas where moisturesensitive floor coverings are anticipated. Soils underlying the slabs should be moistureconditioned and compacted in accordance with the recommendations presented in this report prior to concrete placement. Joints should be constructed at intervals designed by the structural engineer to help reduce random cracking of the slab.

10.3 Retaining Walls
We anticipate that retaining walls will be supported on shallow, spread footings founded on engineered fill. Retaining walls may be designed in accordance with the Caltrans Standard Plans (Caltrans, 2022a). We recommend that unrestrained (yielding) cantilevered retaining walls be designed in accordance with standard Caltrans Type I, V, or equivalent walls. In general, the subgrade soils should provide sufficient bearing capacity to support these retaining walls provided that the remedial grading is performed in accordance with the preceding recommendations. A coefficient of friction of 0.35 should be used between the horizontal surface of the spread footings and the underlying foundation material in order to evaluate resistance against sliding. A passive resistance value of 350 psf per foot of depth should be used in evaluating the lateral resistance of the structural footings. The allowable lateral resistance should be taken as either the sum of 50 percent of the frictional resistance and 50 percent of the passive resistance, or 100 percent of the frictional resistance only, or 100 percent of the passive resistance only, whichever is lower. Details regarding the foundations for the proposed retaining walls (type, size, loads, etc.) were not available at the time of our evaluation. Revised recommendations for the retaining walls should be provided during the design phase.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 24 Unrestrained (yielding) cantilevered retaining walls should be designed for an equivalent fluid weight of 37 and 57 psf per foot for level and 2:1 (horizontal to vertical) sloping backfill, respectively. Restrained retaining walls may be designed for an equivalent fluid weight of 57 and 82 psf per foot for level backfill and 2:1 (horizontal to vertical) sloping backfill, respectively. These values assume free-draining conditions. Lateral earth pressures recommended for design of yielding and restrained retaining walls are provided on Figures 12 and 13, respectively. Live load surcharges should be applied with an equivalent soil depth consistent with the provisions of the AASHTO LRFD Bridge Design Specifications (8th Edition) with California Amendments. The dynamic lateral earth pressures for retaining walls were evaluated using the Mononobe-Okabe Method based on the underlying soil characteristics that may induce lateral movement of the retaining walls. For restrained retaining walls, application of the additional dynamic component will not be needed considering the at-rest earth pressure condition.

Retaining walls should have non-expansive backfill and free-draining conditions. Measures should be taken to reduce moisture build-up behind retaining walls. Wall backfill should meet the specifications for structure backfill (Caltrans, 2022b) for free-draining conditions. Abutment walls should include free-draining backfill materials and perforated drains as designed by the project civil engineer and should be constructed in accordance with Bridge Detail 3-5 on Plan B0-3 of the Standard Plans (Caltrans, 2022a). Typical subsurface drain details are presented on Figure 14.

10.3.1 Tieback Anchors
If the lateral deflection of the cantilevered portion of the retaining walls is excessive, tieback anchors may be appropriate to increase the stability of the retaining wall system. We anticipate that the proposed retaining wall at the north abutment of California State Route 57 will be braced with tieback anchors. Tieback anchors should be designed in accordance with the Ground Anchor Earth Retaining Systems section of the Caltrans Geotechnical Manual (2024c). Multiple rows of tieback anchors should be installed during cutting of the existing slope (top-down construction). A preliminary allowable unit pullout resistance of 1,500 psf should be considered in design for the bonded portion of the anchor. The anchors should be placed at an angle of approximately 15 degrees below the horizontal plane and spaced accordingly in the horizontal and vertical directions to meet the design loads. An effective bond diameter of at least 12 inches should be used in estimating the bond length of the grouted anchors. Depending on the grouting method employed during construction, the actual bond diameter may be larger than 12 inches. Moreover, the design bond length may be revised based on the pullout testing of the anchors during construction. A friction coefficient of 0.35 may be used for the tieback anchors and soil interface. The tieback lengths Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 25 may also need modification if underground utilities are present near the slope areas. More detailed recommendations for the tieback anchors (length, spacing, locations, etc.) should be provided during the detailed design phase of the project once detailed drawings are available after the additional borings have been performed for the project.

10.3.2 Tieback Anchor Construction Considerations
The anchor installation and wall construction should be performed by a specialized contractor having significant experience in tieback installations. The construction should be performed in a phased, “top down” manner starting at the top of the slope and proceeding gradually to the bottom. In each phase, anchor installation in a row should be preceded by removal of unsuitable materials (e.g., loose topsoil) from the slope face and followed by placement of the wall lagging. Slope excavations should be performed in accordance with the published guidelines of OSHA. On-site soil materials may be considered as Type C soils in accordance with the OSHA guidelines.

The anchors should be installed at the design angle below the horizontal plane with a tolerance of ±2 degrees at the bearing plate. The bonded portion of the anchor should be filled with structural concrete or grout following placement of the tendon inside the anchor hole. We recommend the use of high-pressure grouting technique for installation of the anchors with effective grout pressure of 50 psi or higher. The grouting pressure may increase the effective diameter of the bonded portion of the anchor (grout bulb) by permeating into the subsurface soils. The pullout capacity of these anchors will be dependent predominantly on the success of applying and maintaining a high grout pressure during installation. The unbonded portion of the anchor may be filled with lean concrete, slurry, or clean sand.

However, the unbonded portion of the anchor should be free to move.

Anchor installation and wall construction should be observed by Ninyo & Moore. The contractor should provide equipment and instrumentation needed to check placement of tendons and concrete within the anchor holes. The grout pump should be equipped with a pressure gauge capable of measuring a grout pressure of up to 100 psi. The quantity of grout and the grout pressure should be recorded by the contractor for each anchor. The anchors should be tested to check the design allowable pullout capacity.

10.3.3 Tieback Anchor Testing
The tieback anchors should be tested during construction to evaluate the design assumptions and allowable pullout capacities. The contractor should provide equipment and instrumentation needed to check the adequacy of the tiebacks. A dial gauge capable of Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 26 measuring displacements to 0.01-inch precision should be used to measure the anchor movement. A hydraulic jack and pump should be used to apply the test load, and the jack and a calibrated pressure gauge should be used to measure the load. The standard testing procedures typically consist of the following methods.
• Performance Tests – These tests are performed on a limited number of production anchors to check that 1) the design load may be safely carried, 2) effective bonded length corresponds to the design requirements, and 3) the residual movement is within tolerable range. The performance test consists of incrementally applying cycles of anchor loading and unloading until the reference test load is attained. In order to evaluate the long-term creep potential, each load increment is maintained until the measured deflection is negligible (i.e., displacement rate is smaller than a specified displacement increment per log cycle of load-hold time) and a creep test is conducted under the reference test load.

The reference test load should be 200 percent of the design allowable pullout capacity. A “long” test should be performed over 24 hours based on a maximum total deflection of 12 inches and maximum deflection after load application of 0.75 inch. A “short” test should be performed over 30 minutes based on a maximum total deflection of 12 inches and maximum deflection after load application of 0.25 inch. The “long” performance test should be conducted on three of the tieback anchors and the “short” performance test should be conducted on five percent of the tieback anchors.
• Proof Tests – These tests are performed on each tieback anchor to check that the loaddeflection behavior of the production anchor is consistent with the specified acceptance criteria. The proof test consists of a single cycle of incremental loading to the reference test load (i.e., 150 percent of the design allowable pullout capacity) followed by unloading.

Each load increment is maintained until the measured deflection is negligible.

The performance and proof test schedules for the anchors, including the load increments, load hold periods, acceptance criteria, and repair mechanism of failed test anchors, should be developed by the contractor utilizing experience on similar projects and anchor design/testing recommendations and guidelines presented in this report. In general, the acceptance criteria for the tested anchors should be based on the following aspects. • In order to allow the load transfer to reach the anchor bond length, the deflection of the anchor head should exceed 80 percent of the calculated elastic elongation of the unbonded tendon length.
• Total anchor deflection measured at the reference test load should not exceed the calculated elastic elongation of the tendon length measured from the anchor head to the center of the bond length.
• Creep displacement should not exceed 0.10 inch during the final log cycle of the load-hold period.

The test schedules of the tieback anchors and the acceptance criteria should be included in the project plans. Ninyo & Moore should be given the opportunity to review the project plans to check compliance with design and construction recommendations presented herein.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 27 In order to maintain the long-term performance of the tieback anchors, the anchor head and the unbonded portion of the tiebacks should be protected against corrosion. Various corrosion protection methods are commercially available (e.g., anticorrosion grease, resin-bonded epoxy, encapsulation, secondary grouting, etc.). A corrosion protection method suitable for the present application should be provided by a specialized contractor who has experience with tieback installation in similar environment.

10.4 Preliminary Pavement Design
We anticipate that the new multi-use paths may consist of new asphalt concrete (AC) and Portland Cement Concrete (PCC) pavement. Traffic loading information was not available for our design at the time of preparation of this report. For planning purposes, we have assumed traffic index (TI) values of 5.0 and 6.0 for the preliminary design of pavement sections. A TI of 5.0 is generally used for designing pavements that will be subjected to relatively light passenger vehicles. A TI of

6.0 is generally used for designing pavements that are subjected to relatively light passenger vehicles and periodic heavy equipment/truck traffic.

We performed preliminary pavement design based on our evaluation of the subgrade soil conditions and review of previous laboratory testing. Laboratory testing performed on representative subgrade soil samples in the project vicinity performed by others indicated Rvalues ranging from approximately 72 to 74. Due to the variation of subgrade soils along the alignment, a design R-value of 60 was assumed in our preliminary analysis. Our pavement analysis was performed using the methodology outlined by the Highway Design Manual (Caltrans, 2023b) and the Navy Pavement Design Manual (Naval Facilities Engineering Command [NAVFAC], 1979). The analysis assumes an approximately 20-year design life for new pavement.

For the design of PCC pavement, we assumed a 28-day compressive strength of concrete of 2,500 psi. The preliminary pavement section recommendations are summarized in Table 4.

Table 4 – Preliminary Structural Pavement Sections
Traffic Index AC/CAB or CMB
(inches)
Full Depth AC
(inches) PCC (inches)
≤5.0 3 over 4.5 4 5.5

6.0 4 over 4.5 5 6
Notes:

AC – Asphalt Concrete
CAB – Crushed Aggregate Base
CMB – Crushed Miscellaneous Base
PCC – Portland Cement Concrete with a 28-day compressive strength of 2,500 psi We recommend that approximately 2 inches of crushed aggregate/miscellaneous base be placed under the PCC. Prior to placement of aggregate base materials, we recommend that the top 12 inches of subgrade soils be scarified and compacted to a relative compaction of 90 percent in Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 28 accordance with ASTM D 1557. If full-depth AC pavement is used, we recommend that the subgrade soils be recompacted to a relative compaction of 95 percent.

Aggregate base material should conform to the latest specifications in Section 200-2.2 for crushed aggregate base or Section 200-2.4 for crushed miscellaneous base of the Greenbook and should be compacted to a relative compaction of 95 percent in accordance with ASTM D 1557. AC should conform to Section 203-6 of the Greenbook and should be compacted to a relative compaction of 95 percent in accordance with ASTM D 1560 or California Test Method (CT) 304.

Pavement sections should be selected based on actual anticipated traffic loading conditions and evaluation of the subgrade materials, including R-value testing, at the time of construction. We recommend that the paving operations be observed and tested by Ninyo & Moore. We further recommend that the mix design for the various pavements be made by an engineering company specialized in this type of work.

10.5 Decomposed Granite Trails
Decomposed granite, if used, should have a thickness of 6 inches underlain by 4 inches of aggregate base material. Prior to placement of the new natural surface trail, the upper approximately 12 inches of the subgrade beneath new natural surface trail should be scarified, moisture-conditioned, and compacted to a relative compaction of 90 percent as evaluated by ASTM D 1557.

The aggregate base material should be placed at a relative compaction of 95 percent or more as evaluated by ASTM D 1557. Aggregate base material should conform to the latest specifications in Section 200-2.2 for CAB or Section 200-2.4 for CMB of the Greenbook.

10.6 Corrosivity
The corrosion potential of the site soils was evaluated using the results of selected representative samples obtained in the project vicinity performed by others. Laboratory testing was performed to evaluate pH, minimum electrical resistivity, soluble sulfate, and chloride content. The soil pH and minimum resistivity tests were generally performed in accordance with CT 643. The test for chloride content of the soils was generally performed using CT 422. Sulfate testing was performed in general accordance with CT 417. The previous laboratory test results are presented in Appendix B.

The pH of the tested samples ranged from approximately 7.5 to 8.1. The electrical resistivity ranged from approximately 1,900 to 13,000 ohm-centimeters. The chloride content ranged from Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 29 approximately 10 to 128 ppm and the sulfate content ranged from non-detect to 0.0950 percent (i.e., 950 ppm). Based on the laboratory test results and Caltrans criteria (2021b), the project site can be classified as a non-corrosive site, which is defined as having earth materials with a pH of

5.5 or more, chloride concentrations of 500 ppm or less, sulfate concentration of 0.15 percent (i.e., 1,500 ppm) or less, or an electrical resistivity of 1,500 ohm-centimeters or more. We recommend that a corrosion engineer be consulted for further evaluation and recommendations.

10.7 Concrete Placement
Based on the CBC (2022), the potential for sulfate attack is negligible for water-soluble sulfate contents in soil ranging from 0.00 to 0.10 percent by weight, moderate for water-soluble sulfate contents ranging from 0.10 to 0.20 percent by weight, severe for water-soluble sulfate contents ranging from 0.20 to 2.00 percent by weight, and very severe for water-soluble sulfate contents over 2.00 percent by weight. The soil samples tested during the previous geotechnical evaluations in the project vicinity performed by others, using CT 417, indicates water-soluble sulfate contents ranging from approximately non-detect to 0.0950 percent (i.e., 950 ppm). Accordingly, the on-site soils are considered to have a negligible potential for sulfate attack. However, due to the potential variability of the on-site soils and since the test results are close to the moderate range, consideration should be given to using Type II/V cement for the project In order to reduce the potential for shrinkage cracks in the concrete during curing, we recommend that the concrete for the proposed structures be placed with a slump of 4 inches based on ASTM C 143. The slump should be checked periodically at the site prior to concrete placement.

We recommend that concrete cover over reinforcing steel for foundations be provided in accordance with CBC (2022). We also recommend that crack control joints be provided in sidewalks and exterior hardscape in accordance with the recommendations of the structural engineer to reduce the potential for distress due to minor soil movement and concrete shrinkage.

The structural engineer should be consulted for additional concrete specifications.

10.8 Drainage
Positive surface drainage is imperative for satisfactory site performance. Positive drainage should be provided and maintained to direct surface water away from foundations and off-site. Positive drainage is defined as a slope of 2 percent or more for a distance of 5 feet or more away from foundations and tops of slopes. Runoff should then be directed by the use of swales or pipes into a collective drainage system. Surface water should not be allowed to pond adjacent to foundations or pavement. Area drains for landscaped and paved areas are recommended.

Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 30 11 CONSTRUCTION MONITORING PROGRAM
To reduce the potential for construction related claims, construction monitoring programs should be implemented to monitor ground vibrations, ground surface settlement, and lateral movement of shoring support systems. These monitoring programs should be in-place and conducted prior to the start of construction to reduce the potential for damage claims and to facilitate settlement of legitimate damage claims. The resulting data should be reviewed and evaluated during construction and distributed to appropriate parties during the course of construction.

11.1 Documentation of Existing Conditions
We recommend that pre-construction condition surveys be performed on structures and railroad crossings within approximately 50 feet of the proposed excavations prior to construction. This distance should be extended to 100 feet adjacent to proposed excavations if driven and/or vibratory sheet or soldier piles are installed. This survey should include locating existing cracks and measuring widths of cracks, in combination with video documentation of existing conditions.

In addition, interviews should be conducted with utility owners so that existing knowledge about the age, type, and maintenance history of affected utilities is available prior to construction.

11.2 Construction Vibrations
People can perceive vibrations from construction activities at significantly lower levels than might cause cosmetic damage to structures. The Transportation and Construction Vibration Guidance Manual (Caltrans, 2020) indicates that transient vibrations, such as from pile installation or construction activities, may be noticeable at peak particle velocities as low as 0.035 inches per second (ips). The vibrations from the construction activities may be disturbing and result in complaints and/or damage claims at peak particle velocities as low as 0.2 to 0.4 ips. However, these vibration levels are well below the level considered to cause cosmetic damage to residential construction.

There is also the possibility of settlement of the soil during construction activities due to vibrations.

This settlement may result in damage to structures and improvements. If the construction vibrations can be maintained below a peak particle velocity of 0.2 ips, the settlement can likely be limited to acceptable levels based on past projects in similar conditions.

For the above stated reasons, we recommend that seismographs be used in the early stages of construction to monitor the vibrations. Seismographs should be located near structures and improvements next to the construction activities. Additional seismographs should be located at various structures and improvements farther from the construction activities to monitor vibrations Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 31 as a function of distance from the sites. Periodic vibration monitoring is recommended during other construction activities. After review of the data obtained, the number of seismographs may be reduced at the discretion of the client and the geotechnical consultant.

11.3 Ground Surface Settlement
We recommend that arrays of ground surface settlement points be installed around the proposed excavations. The contractor should submit a monitoring plan showing the proposed locations of settlement points for review and approval by the project engineer. We recommend that the contractor be responsible for maintaining total settlement at any survey point to less than 0.5 inch.

If the settlement reaches this limit, we recommend that further review of construction methodologies be performed and appropriate changes be made.

11.4 Lateral Movement for Shoring Support System
It may be appropriate to install inclinometers or establish survey points behind excavations next to existing slopes. The inclinometers or survey points should be monitored and evaluated daily during excavation activities to provide an advanced warning system of potential problems. As discussed previously, we recommend that the shoring system be designed to limit the ground settlement behind the shoring system to 0.5 inch or less to reduce the potential for distress to adjacent structures/improvements. If settlements reach 0.25 inch, we recommend that a review of the contractor’s methods be performed and appropriate changes be made, if needed.

11.5 Groundwater Monitoring
If construction dewatering is performed, settlement of the ground surface and adjacent structures may also be caused by drawdown of the water table. We recommend that the contractor monitor water levels outside of the excavations. To monitor the groundwater levels outside of the excavations, we recommend that groundwater monitoring wells be installed. The monitoring wells should be installed at locations that will be accessible during construction. The groundwater levels should be monitored daily during dewatering as appropriate. 12 ADDITIONAL GEOTECHNICAL STUDIES
The available subsurface information does not provide sufficient data to complete the design recommendations for the OC River Walk Project. This geotechnical evaluation was performed for preliminary planning purposes. During its design phase, the structure details and locations may change. We are scheduled to perform a subsurface evaluation and geotechnical laboratory testing after the project team receives Section 404 and 408 permission from the USACE and after our Drilling Program Plan is approved. We will perform supplemental geotechnical engineering Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 32 analyses and prepare an updated geotechnical evaluation report for the project based on the findings from our subsurface evaluation. The design of project improvements should be based on the subsequent geotechnical evaluation results and recommendations. 13 LIMITATIONS
The geotechnical analyses presented in this report have been conducted in accordance with current engineering practice and the standard of care exercised by reputable geotechnical consultants performing similar tasks in this area. No other warranty, implied or expressed, is made regarding the preliminary conclusions, recommendations, and professional opinions expressed in this report. Our preliminary conclusions and recommendations are based on a review of readily available geotechnical literature, geologic and seismic data, and an analysis of the observed conditions. Variations may exist and conditions not observed or described in this report may be encountered
This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document.

This report is intended exclusively for use by the client and for preliminary design. This report is not intended for final design. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties’ sole risk.

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Ninyo & Moore | OC River Walk, Anaheim and Orange, California | 212076001 | October 11, 2024 39 United States Geological Survey, 2008, National Seismic Hazard Maps, http://geohazards.usgs.gov/cfusion/hazfaults_search/hf_search_main.cfm.

United States Geological Survey, 2022, USGS US Topo 7.5-Minute Map for Anaheim, CA: USGS – National Geospatial Technical Operations Center.