TO:Andrew P. Powers, City Manager
FROM:Nader Heydari, Public Works Director
DATE:April 14, 2026
SUBJECT: South Branch Arroyo Conejo Floodplain Improvements Study (MI 2527) Second Amendment
RECOMMENDATION:
1. Approve Second Amendment to Professional Services Agreement (Contract No. 13355-2023) with Kasraie Consulting (Ventura, CA), for additional drainage and hydrology study analysis in the amount of $207,582, for a revised not-to-exceed amount of $480,687, plus extra services of $7,418, and extending the term to June 30, 2027.
2. Approve budget appropriation and expenditure in FY 2025-26 in the amount of $215,000 from A/C #001-0000-311-1000 (General Fund – Fund Balance) to A/C #001-5210-642-5699 (General Fund – Contracted Services – MI 2527).
3. Approve revenue budget appropriation in the amount of $86,000 in FY 2025-26 from A/C #001-0000-437-9900 (General Fund – Revenue from Agency) to A/C #001-0000-311-1000 (General Fund, Fund Balance) for South Branch Arroyo Conejo Floodplain Improvements Study (MI 2527).
4. Find that this action is not a project as defined under the California Environmental Quality Act.
LEVINE ACT ITEM: Yes
FINANCIAL IMPACT:
$215,000 Increase to Adopted FY 2025-26 General Fund Budget Partially Offset by up to $86,000 Contribution from Ventura County Watershed Protection District (VCWPD). $215,000 increase to the Adopted FY 2025-26 General Fund Budget for MI 2527. The estimated cost of this phase of the project is $215,000, to be offset by a 40 percent contribution by VCWPD for eligible expenditures (up to $86,000).
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BACKGROUND:
The South Branch Arroyo Conejo (SBAC) Channel is located in Newbury Park, the southwest area of the City of Thousand Oaks. In 2010, the Federal Emergency Management Agency (FEMA) revised flood maps in Newbury Park that included over 300 homes within City limits and unincorporated County areas. The revisions to the maps impacted residents in this area with a flood designation, requiring some homeowners to obtain flood insurance.
In 2011, an independent consultant study of the floodplain found that the existing drainage structures are not sufficient to convey a 100-year flood. The City contacted the Los Angeles District Office of the U.S. Army Corp of Engineers (USACE) to assist in determining the best solution. Available funding from the USACE could enhance conveyance capacity by implementing flood channel improvements and protect local residential and commercial communities from flood damage, potentially reducing the area floodplain designation and enabling many property owners and businesses to avoid purchasing flood insurance.
In 2014, the USACE funded and conducted a Federal Interested Determination that pre-qualified the SBAC under Section 205 for investigating and implementing solutions that could authorize up to $10 million in federal funds to analyze, study, and construct water flow solutions.
In 2015, the USACE initiated a Phase II Feasibility Study, which included an analysis of the area to determine justifiable financing of possible mitigation improvements. In 2018, the City and VCWPD approved a project management plan and cost-sharing agreement for the Phase II Feasibility Study.
In 2020, USACE made preliminary conclusions that recommended against the completion of a full Feasibility Study of the SBAC, due to substantially lower cost- benefit ratios than previously estimated. It was also noted that flooding in the SBAC may occur because of a low capacity in the existing culverts as opposed to the floodplain channel, meaning significant damage of more than $1 million from a 100-year flood incident would not be caused by the floodplain channel itself, and thereby disqualifying the City and surrounding area from additional federal support.
The USACE recommended the City and VCWPD pursue local versus federal funding solutions to mitigate area flooding issues. The City, in cooperation with VCWPD, developed a draft Scope of Work for a formal Request for Proposals/Qualifications (RFP/Q) and the selection of a consultant to complete a Hydrology Deficiency Study (Study) for the SBAC. The project area includes the 101 Freeway/Borchard Road interchange to the intersection of Reino Road at Borchard Road.
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A Professional Services Agreement with Kasraie Consulting (Kasraie) in the amount of $262,402 was approved by City Council on July 18, 2023. As the hydrology and hydraulic models were developed, several interested property owners within the Study area contacted staff with regard to expected Study outcomes. In order to ensure accurate and objective Study results, the Public Works Department issued a task order in June 2025, using available on-call consultant funding, to hire J. Smith & T. Muli, Inc. to conduct a peer-review of the draft Study results.
The First Amendment to the Kasraie agreement was processed under City Manager authority on July 11, 2025, adding $10,703 from approved extra services funds to the contract for Kasraie to further review historic floodplain data, provide a Flood Insurance Rate Map listing affected properties, assist with public outreach, and coordinate responding to peer-reviewer comments with minor study report updates.
The City and VCWPD developed a Memorandum of Agreement (MOA) between the two agencies that includes a cost-sharing arrangement for the project based on the overall level of effort for each jurisdiction (60 percent to the City and 40 percent to VCWPD for eligible expenditures related to the County portion of the project). City Council approved the MOA on July 18, 2023, and the County Board of Supervisors approved the MOA on July 25, 2023.
DISCUSSION/ANALYSIS:
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Kasraie has developed a computational model to evaluate the drainage system and hydrology across the South Branch watershed area and has reviewed the comments provided by the peer reviewer. To address the provided comments, staff recommend that Kasraie conduct additional analysis on inputs to the model, as well as add language to the draft report to respond to the peer-reviewer’s comments. The additional analysis will require modeling, and therefore, staff are requesting that Kasraie extend and expand the model to both address the review comments and prepare the model for eventual review by FEMA. Further, the added scope in this amendment will enable Kasraie to assist the City with a comprehensive public data and information collection effort, allowing stakeholders to contribute materials into the analysis, as the report and model are further developed.
It is expected that this collection effort will occur over Spring-Summer 2026. The draft report is expected to be completed in late 2026 or early 2027, at which time it will be posted online for public review. Staff recommends approving this Second Amendment to the Professional Services Agreement with Kasraie (Attachment #1) in the amount of $207,582 (total not-to-exceed amount of $480,687), and an extra services budget of $7,418, with an expanded Scope of Work, and extending the term of the agreement to June 30, 2027.
Community Outreach: A public outreach plan for the project has been developed, with a focus on residents and businesses located within the project boundaries. A project website will be created to provide a portal for the public data and information collection effort, as well as to provide a copy of the draft report once it is completed in early 2027.
This project meets City Council’s Top Ten Priorities #9, “Public Works Infrastructure Investments.”
CIP PROJECT PRIORITY (as outlined in FY 2025-26 and FY 2026-27 CIP Program Budget)
Priority One – Essential projects which addresses health and safety, legal and regulatory requirements, as well as City Council’s Top Priorities projects.
LEVINE ACT (California Government Code § 84308):
This item is subject to the Levine Act. City Councilmembers who have received a campaign contribution of more than $500 (aggregated) within the preceding 12 months from a party or their agent/representative, or a financially-interested participant involved in this proceeding may do either of the following: (1) disclose the contribution on the record and recuse themselves from this proceeding; or if applicable (2) return the portion of the contribution that exceeds $500 within 30 days from the time the official knew or should have known about the contribution, SBAC Floodplain Improvements Study (MI 2527) Second Amendment April 14, 2026
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and participate in the proceeding.
All parties and their agents/representatives must disclose on the record of this proceeding any aggregated contribution of more than $500 made to any Councilmember within the preceding 12 months. Councilmembers are prohibited from accepting, soliciting, or directing a campaign contribution of more than $500 (aggregated) from a party, their agent/representative, or a financially-interested participant during a proceeding and for 12 months following the date a final decision is made. In addition, a party, their agent/representative, or a financially- interested participant is prohibited from contributing more than $500 (aggregated) to a Councilmember during a proceeding and for 12 months following the date a final decision is made. The completed Levine Act Form for Kasraie is included as an exhibit to the contract in Attachment #1.
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COUNCIL GOAL COMPLIANCE:
Meets the following City Council goals:
C. Operate City government in a fiscally and managerially responsible and prudent manner to ensure that the City of Thousand Oaks remains one of California's most desirable places to live, work, visit, recreate, and raise a family.
F. Provide and enhance essential infrastructure to ensure that the goals and policies of the Thousand Oaks General Plan are carried out and the City retains its role and reputation as a leader in protecting the environment and preserving limited natural resources.
PREPARED BY: H. Ted Gerber, Deputy Public Works Director/City Engineer Attachments:
Attachment #1 – Second Amendment to Contract No.13355-2023 with Kasraie
DPW: 850-20\ev\Council\2026\041426\SBAC Floodplains Improvement Study staff report.docx