PROJECT INFORMATION

Project Manager: City of Belmont, Elizabeth Wada, P.E., Senior Civil Engineer, ewada@belmont.gov

Consultant: Craftwater Engineering, Inc.

Funding:

• California Natural Resources Agency (CNRA) General Fund Grant (Design)
• CNRA Urban Flood Protection Grant (Construction)
• Tri-agency Local Match Cost Share - City of Belmont, City of San Carlos and San Mateo County (Construction)

The City of Belmont is the Lead Agency for this project.

Project Scope:

The Twin Pines Storm Water Detention Basin Project (Project) scope includes the completion of engineering design, CEQA review, environmental permitting, bid package execution and construction. This Project is an effort to follow the City’s “Twin Pines Park Master Plan” and “Belmont Creek Watershed Management Plan” to reduce flooding within the Belmont Creek Watershed, specifically within the Harbor Industrial Area.

The Project’s underground storage facility will be located beneath the parking lots or other areas of the 10-acre Twin Pines Park, and is designed to attenuate the peak stormwater flow of Belmont Creek, to trap sediment and debris, to reduce flood risk in the flood-prone lower creek reach downstream of El Camino Real, and to provide ancillary water quality benefits. A diversion weir would divert high flows from Belmont Creek to the 9-acre-foot underground storage facility, where water would remain before flowing back into Belmont Creek through a 12-inch outlet pipe. The Project would also include a sediment chamber, bank stabilization at the basin inlet and outlet within Belmont Creek, and an in-stream check structure in Belmont Creek. 

MEETINGS & NOTICES

City Council Meeting (Agenda)
September 10, 2024 at 7:00 PM

Final Environmental Impact Report (EIR)

• Twin Pines Park Stormwater Detention Basin EIR

• Appendices

  • Appendix A - NOP and Scoping Comments
  • Appendix B - Initial Study
  • Appendix C - Air Quality
  • Appendix D - Biological Resources
  • Appendix E - Belmont Creek Watershed Plan

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Planning Commission Public Hearing (Agenda)
June 4, 2024 at 7:00 PM

• Notice of Preparation
• Notice of Availability

Draft Environmental Impact Report (DEIR)

At this time, the public review period is closed.

A Draft Environmental Impact Report (DEIR) was prepared to evaluate the potential environmental consequences of implementation (i.e., construction and operation) of the proposed Stormwater Detention Basin Project. The DEIR is a very large document and has been posted in multiple sections to make it easier to read and navigate through.  Studies and reports that have been used to evaluate the project are included in the DEIR Appendices Links.    

The City prepared this Notice of Availability (NOA) to invite agencies, organizations, and interested parties to provide comments on the DEIR. The public review period for the DEIR began May 14, 2024, and ended at 5:00 p.m. on June 28, 2024. Due to the time limits mandated by State law, the City must receive all written comments regarding the adequacy of the DEIR by 5:00 p.m. on June 28, 2024.  

Written comments were accepted by the Lead Agency (Belmont) contact identified below, with “Stormwater Detention Basin Project EIR” as the subject. Public agencies that provide comments are asked to include a contact person for the agency. For the official record, please date and reference the project name, Twin Pines Park Stormwater Detention Basin Project.

Lead Agency Contact:

Public Works Department
Attn: Elizabeth Wada
One Twin Pines Lane, Suite 385
Belmont, CA 94002 

Email: ewada@belmont.gov 

Printed copies of the DEIR are available for review Monday through Friday, between the hours of 8:00 a.m. and 5:00 p.m., at the Public Works Department, One Twin Pines Lane, Suite 385, Belmont, except on specified holidays. The DEIR is also available at the Belmont Public Library, 1110 Alameda de Las Pulgas, Belmont. 

Twin Pines Park Stormwater Detention Basin Project (Draft EIR)

• Cover Page
• Executive Summary
• Chapter 1 - Introduction
• Chapter 2 - Project Description
• Chapter 3 Environmental Setting, Impacts, and Mitigation Measures
• 3.1 - Overview
• 3.2 - Air Quality and Greenhouse Gas Emissions
• 3.3 - Biological Resources
• 3.4 - Cultural Resources
• 3.5 - Hydrology and Water Quality
• 3.6 - Tribal Cultural Resources
• Chapter 4 - Other CEQA Issues
• Chapter 5 - Alternatives
• Chapter 6 - Report Preparers

Appendices

• Appendix A - NOP and Scoping Comments
• Appendix B - Initial Study
• Appendix C - Air Quality
• Appendix D - Biological Resources
• Appendix E - Belmont Creek Watershed Plan

PROJECT UPDATES

July 2024: 90% design received and is under City review.

May 14, 2024 to June 28, 2024: Draft EIR available for public comment. 

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October 4 to November 3, 2023: Posted Notice of Preparation (NOP) posted for draft Environmental Impact Report (EIR).

June 2023: 60% design complete.

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October 2022: Cultural Resource investigations were initiated by subconsultants Environmental Science Associates.

August 2022: Engeo, Inc., the geotechnical subconsultant for the project, performed the geotechnical investigation in the City Hall parking lot. This consisted of two boring locations in the upper and lower portions of the parking lot. Wood Rodgers, another subconsultant, also provided preliminary hydrology and hydraulic analysis to move the design forward.

May 2022 – July 2022: Craftwater compiled existing information about the project from the City and other public records. The City also had informational tables about the project at the July 24 and July 31 “Concerts in the Park” event in Twin Pines Park.

April 2022: The City and Craftwater Engineering met with Restoration Design Group for the first time to coordinate design.

March 2022: The City and Craftwater Engineering kicked off the Detention Basin project.

PROJECT DOCUMENTS

Request for Qualifications (closed on 12/10/21)

Hydrology and Hydraulics Analysis

Storm Water Detention Basin Project - 60% Plans

Outreach Flyer (updated May 2024)

[updated 8/26/2024]