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 Construction of the Palo Alto Flood Basin Tide Gate Structure Seismic Retrofit and Rehabilitation Project, Project No. 10394001, Contract No. CO710 (Palo Alto, District 7).
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RECOMMENDATION: Recommendation
A. Adopt the Plans and Specifications and Authorize Advertisement for Bids for Construction of the Palo Alto Flood Basin Tide Gate Structure Seismic Retrofit and Rehabilitation Project per the Notice to Bidders; and
B. Authorize the Designated Engineer to issue addenda, as necessary, during the bidding process.
Body
SUMMARY:
The Palo Alto Flood Basin Tide Gate Structure Seismic Retrofit and Rehabilitation Project (Seismic Retrofit and Rehabilitation Project) will implement improvements to the Palo Alto Flood Basin Tide Gate Structure to address seismic vulnerabilities and extend the existing structure’s service life. In addition to the seismic retrofit work, Operations and Maintenance has requested that the scope of the work include replacement of 6 existing hydraulic flap gates that were found to be degraded during routine maintenance inspections. Both seismic retrofit and flap gate replacement activities will be funded by the Watershed Asset Rehabilitation Project (WARP). The entire scope of construction will be completed between September 2025 and October 2026.
Project Background
The primary objective of the Palo Alto Flood Basin Tide Gate Structure (PATG) is to continue to protect residents from coastal flooding and control the downstream water levels for Matadero, Adobe and Barron Creeks, which all drain to the Palo Alto Flood Basin. Originally built in 1957, the PATG has exceeded its 50-year design life, and the surface of the concrete structure has degraded due to harsh conditions near the San Francisco Bay (Bay). The existing structure is also vulnerable to a large earthquake since seismic codes have changed significantly since 1957.
The PATG is regularly inspected and maintained by the Santa Clara Valley Water District (Valley Water), and the motorized sluice gate is regularly inspected and maintained by the City of Palo Alto.
Project Scope
As part of the FY 2023-2024 Adopted Capital Improvement Program (CIP) staff conducted an evaluation to address seismic vulnerabilities and extend the existing structure’s service life. As a result, a project scope to seismically retrofit and rehabilitate the existing structure was developed.
The seismic retrofit and rehabilitation work will include installing deep pile foundations, repairing concrete cracks, repairing the surface of the tide gate deck with a polyester concrete overlay, installing new fence that is safer for pedestrians and bicyclists, and improving access for maintenance work. The Board approved seismic retrofit and rehabilitation activities as the Modified PATG Structure Replacement Project at the October 22, 2024 Board meeting.
Additionally, 6 existing hydraulic flap gates have been found to be deficient during a recent maintenance inspection of the structure. Flap gate replacement is an approved Stream Maintenance Program Update 2012-2022 (SMP) activity. To take advantage of logistical efficiencies from reducing the number of work crews in the same area, minimize potential disruption to publicly accessible recreation areas within the work area, and free up internal Operations and Maintenance resources for other critical work activities, staff recommends combining the flap gate replacement activities with the seismic retrofit activities under one scope of work for construction, collectively referred to as the PATG Structure Seismic Retrofit and Rehabilitation Project.
Construction of the seismic retrofit and rehabilitation work will be completed between September 2025 and January 2026. Replacement of the flap gates will be completed between September 2026 and October 2026.
Staff estimates the construction cost of the Seismic Retrofit and Rehabilitation Project to be $2.1 million to $2.9 million.
Relevant Prior Board Actions
On January 24, 2012, the Board certified the Environmental Impact Report for the Stream Maintenance Program for which the flap gate replacement work for the Seismic Retrofit and Rehabilitation Project will be covered (Resolution No. 12-07).
On April 27, 2021, the Board adopted the Final Mitigated Negative Declaration (MND) and Mitigation Monitoring and Reporting Program (MMRP) for the PATG Structure Replacement Project before approving the Structure Replacement Project (Resolution No. 21-16).
On October 22, 2024, the Board considered modification of the Structure Replacement Project to address seismic retrofit and rehabilitation needs. The Board considered the First Addendum to the Final Mitigated Negative Declaration for the modified PATG Structure Replacement Project and approved the Modified PATG Structure Replacement Project. (Valley Water Board Meeting File #24-0825. Approve the Modified Palo Alto Flood Basin Tide Gate Structure Replacement Project, Project No. 10394001 [Palo Alto, District 7]. October 22, 2024.)
Rights-of-Way
This Seismic Retrofit and Rehabilitation Project will be constructed within Valley Water’s existing right-of-way. For construction access, encroachment permits from the City of Mountain View and City of Palo Alto have been obtained.
Permits
The seismic retrofit and rehabilitation portion of work will be covered under the regulatory permits obtained from the California Department of Fish and Wildlife, the San Francisco Bay Regional Water Quality Control Board, and the San Francisco Bay Conservation and Development Commission.
The hydraulic flap gates scope of work will be implemented using the applicable SMP Update 2012-2022 permits.
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 Seismic Retrofit and Rehabilitation 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.
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.
Public Outreach
Before beginning construction, Valley Water will conduct a preconstruction public meeting to inform the surrounding neighborhood of the Seismic Retrofit and Rehabilitation 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 Seismic Retrofit and Rehabilitation Project construction. Staff anticipates recommending the Board award the construction contract in August 2025. The Seismic Retrofit and Rehabilitation 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 Seismic Retrofit and Rehabilitation Project. This action is unlikely to result in adverse impacts and is not associated with an equity opportunity.
FINANCIAL IMPACT:
The Seismic Retrofit and Rehabilitation Project (Project No. 10394001) is included in the Capital Improvement Program (CIP) Fiscal Years (FY) 2025-29 Five-Year Plan. The estimated cost of construction for the Seismic Retrofit and Rehabilitation Project is between $2.1 million and $2.9 million. The cost for the hydraulic flap gates replacement will be funded under the Watershed Asset Rehabilitation Project (WARP Project No. 62084001). The cost of the construction work for the seismic retrofit and rehabilitation will be encumbered in FY 2025, and cost of the flap gate replacement work will be encumbered in FY 2026. Under the phased encumbrance plan, there are adequate funds in the Board-adopted FY 2024-25 budget to encumber funds for the first year of the Seismic Retrofit and Rehabilitation Project construction. Additional funds will be needed for the second year of the Seismic Retrofit and Rehabilitation Project construction and will be included in the FY 2026-27 budget process. The funding source for the Seismic Retrofit and Rehabilitation Project is the Watersheds Stream Stewardship Fund (Fund 12) under Project Nos. 10394001 and 62084001.
CEQA:
On January 11, 2012, the Board certified the Environmental Impact Report for the Stream Maintenance Program Update 2012-2022, which included authorization of flap gate replacement work (Resolution No. 12-07). A Notice of Determination (Attachment 6) was filed with the State Clearinghouse on February 17, 2012. Copies of the SMP environmental documents may be accessed at https://www.valleywater.org/project-updates/stream-maintenance-program/smp-authorization-documents-and-permits.
On April 27, 2021, the Board adopted the Final MND and Mitigation Monitoring and Reporting Program (MMRP) for the PATG Structure Replacement Project (Resolution No. 21-16). A Notice of Determination (Attachment 7) was filed with the State Clearinghouse on April 29, 2021.
On October 22, 2024, the Board considered the First Addendum to the Final MND for the Palo Alto Flood Basin Tide Gate Structure Replacement Project and approved the Modified Palo Alto Tide Gate Structure Replacement Project. Copies of the environmental documents for the modified seismic retrofit project may be accessed at https://www.valleywater.org/project-updates/palo-alto-flood-basin-tide-gate-structure-replacement-project.
ATTACHMENTS:
Attachment 1: Map
Attachment 2: Notice to Bidders
Attachment 3: Project Delivery Process Chart
Attachment 4: Plans
Attachment 5: Specifications
Attachment 6: SMP Update 2012-2022 Notice of Determination
Attachment 7: PATG Notice of Determination
UNCLASSIFIED MANAGER: Manager
Bhavani Yerrapotu, 408-630-2735