BOARD AGENDA MEMORANDUM
Government Code § 84308 Applies: Yes ☐ No ☒
(If “YES” Complete Attachment A - Gov. Code § 84308)
SUBJECT: Title
Adopt Plans and Specifications and Authorize Advertisement for Bids for the South Babb Flood Mitigation Project, under the Watersheds Asset Rehabilitation Program, Project No. 62084001, Contract No. CO716 (San Jose, District 6).
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RECOMMENDATION: Recommendation
A. Approve the South Babb Flood Mitigation Project;
B. Adopt the Plans and Specifications and Authorize Advertisement for Bids for Construction of the South Babb Flood Mitigation Project per the Notice to Bidders; and
C. Authorize the Designated Engineer to issue addenda, as necessary, during the bidding process.
Body
SUMMARY:
South Babb Creek is a tributary to Lower Silver Creek, which is a 43.6 square mile drainage area within the larger Coyote Creek watershed. The entire section of South Babb Creek is located within the City of San Jose and drains into Lower Silver Creek downstream of the Farringdon Drive bridge.
In 2018, Santa Clara Valley Water District (Valley Water) completed civil construction of floodwalls as part of the Lower Silver Creek Project at the confluence with South Babb Creek. Following construction, Valley Water completed a 100-year flood event study that included a hydrologic and hydraulic model of the Lower Silver Creek watershed in support of the Federal Emergency Management Agency’s (FEMA) Cooperating Technical Partnership program. The results of the hydraulic modeling indicated that, in this event, flood water would spill along South Babb Creek onto the street surface at several bridge crossings. Flood waters would then flow north easterly and pond behind the floodwalls constructed for the Lower Silver Creek Project (Reach 5C), preventing overland drainage back into the creek. The water eventually would flow to the north and flood an apartment complex. FEMA has initiated a Physical Map Revision based on the recent hydraulic modeling, which would add the apartment complex to the regulatory floodplain in a couple years if nothing is done.
The long-term South Babb Flood Protection Project is currently on the CIP unfunded project list. Each year unfunded CIP projects are reevaluated for the Board's consideration for inclusion into the next year's CIP Five-Year Plan. Staff continues to explore grants and other funding opportunities to fund this long-term project and other watershed projects.
To mitigate the short-term impacts to the apartment complex, staff developed several alternatives. In January 2023, the South Babb Flood Mitigation Project (Project) was identified as one of the high priority projects to be implemented under the Watersheds Asset Rehabilitation Program. This Project, the selected alternative, reduces flooding conditions primarily at the apartment complex through the design and construction of underground storm water troughs behind the floodwall and modifying the floodwalls with openings and flap gates, allowing ponding water to drain back to Lower Silver Creek. Staff estimates the construction of this Project will take up to 3 months and cost between $1.4 million to $1.8 million.
Relevant Prior Board Actions
On November 28, 2017, the Board accepted only the Construction Phase of the contract (Milestone 1 as that portion of the Project had been completed) for the Lower Silver Creek Flood Protection and Creek Restoration Project, Reaches 5C-6A, Contract No. CO580.
On January 12, 2021, the Board accepted the Landscape and Revegetation Establishment Maintenance Phase for the Lower Silver Creek Flood Protection and Creek Restoration Project, Reaches 5C-6A, Contract No. CO580.
Rights-of-Way
This Project will be constructed within Valley Water’s existing lands. Construction access through the driveway and parking areas around the apartment complex have been granted through a temporary construction license.
Permits
The Project is a covered activity under the Santa Clara Valley Habitat Plan.
Outreach to Bidders
The Notice to Bidders (Attachment 2) will be sent to the following recipients: 26 plan rooms, 83 minority businesses, 44 Chambers of Commerce, as well as small business groups, certified small business contractors, and local and regional firms that have the appropriate license for this type of work, and the Santa Clara and San Benito Counties Building & Construction Trades Council, which maintains contacts with at least 1048 contractors and 70 union representatives. The total number of entities to be notified in PlanetBids is 1322.
Board Adoption of Plans and Specifications and Addenda Authorization
Board adoption of plans and specifications and Board authorization to advertise is recommended to proceed to bid the Project for construction. Authorizing the Designated Engineer to issue addenda during the bidding period allows for modifications to the construction Contract Documents, if necessary, during the bidding period and before the contract is awarded.
Public Outreach
Before beginning construction, Valley Water will inform the surrounding neighborhood of the Project and potential construction impacts. A mailer and social media will be used to reach out to neighbors, and construction site signage will be installed once the contractor has begun the work.
Next Steps
If the Board approves the recommendations, staff will proceed to advertise for bids for Project construction. Staff anticipates recommending the Board award the construction contract in June 2025. The Project Delivery Process Chart (Attachment 3) highlights the current Project phase and the staff recommendations before the Board.
ENVIRONMENTAL JUSTICE AND EQUITY IMPACT:
There are no environmental justice and equity impacts associated with the South Babb Flood Mitigation Project. This action is unlikely to result in adverse impacts and is not associated with an equity opportunity.
FINANCIAL IMPACT:
The Project is included in the Watersheds Asset Rehabilitation Program (WARP), Project No. 62084001. The WARP is included in the Five-Year FY2025-2029 Capital Improvement Program (CIP). The estimated cost of construction for the Project is between $1.4 million and $1.8 million. There are adequate funds in the Board-adopted FY2024-25 budget to encumber funds for Project construction. The funding source for the Project is the Watersheds Stream Stewardship Fund 12.
CEQA:
Valley Water is the lead agency under the California Environmental Quality Act for implementation of the Project. This Project is exempt under CEQA Guidelines Section 15301, which exempts minor alterations of existing public facilities, and CEQA Guidelines Section 15304, which exempts minor alterations in the condition of the land. A Notice of Exemption has been prepared and will be filed with the Santa Clara County Office of the Clerk-Recorder following Board approval of the Project.
ATTACHMENTS:
Attachment 1: Map
Attachment 2: Notice to Bidders
Attachment 3: Project Delivery Process Chart
Attachment 4: Plans
Attachment 5: Specifications
UNCLASSIFIED MANAGER: Manager
Bhavani Yerrapotu, 408-630-2735