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Capital project
Corte Madera Creek Flood Risk Management Project
Date
Watershed Reference

Also known as the U.S. Army Corps of Engineers Corte Madera Creek Flood Control Project (Units 2, 3, & 4)

About the Project

Project Description

The primary goal of the Corte Madera Creek Flood Risk Management Project (Project) is to reduce the frequency and severity of flooding and to protect human life and property in the communities of Ross and Kentfield by enhancing and improving Corte Madera Creek. The Project will include removal of the wooden fish ladder, widening the channel by removing portions of the concrete channel to create flood plains and riparian corridors, installing flood walls adjacent to the banks and stabilizing creek slopes. The Project benefits include flood reduction during large storms and ecosystem restoration.

The Project is being phased in order to move priority flood reduction measures in Ross and Kentfield years ahead of the larger Project’s schedule by utilizing a $7.6 M grant from the Department of Water Resources (DWR). In June 2017, the Flood Zone 9 Advisory Board approved reallocating DWR grant funds from the Phoenix Lake Integrated Regional Water Management Project (determined to be infeasible as proposed due to grant restrictions) to create Phase 1 of the Corte Madera Flood Risk Management Project. 

Photos: Fish ladder shown during low level (left) and during 2017 storm flows (right) in Corte Madera Creek across concrete channel at Frederick Allen Park, Ross.
Photos: Fish ladder shown during low level (left) and during 2017 storm flows (right) in Corte Madera Creek across concrete channel at Frederick Allen Park, Ross.

 

Phase 1 Description

Documents in bold are below in Documents section

Phase 1 would be constructed by 2020 and includes removing obstructions (such as the Ross fish ladder) and widening the channel (creating a flood plain and riparian corridor at Frederick Allen Park) to keep more water in Corte Madera Creek during large flood events. Phase 1 also includes making improvements to the earthen channel above the fish ladder and adding protective floodwalls along the channel downstream in Kentfield at the Granton Park neighborhood. These measures are being prioritized as residents and business in these areas flood at even the smaller flood events, such as experienced in the winter 2016-17. This opportunity also leverages state funds to offset the required local funding share of design and construction of the project. 

Learn more about the proposed Frederick Allen Park Riparian Corridor conceptual plans by reviewing the draft drawings: Existing ConditionsDraft Conceptual Plan, and the Draft Conceptual Section.

Goals of the Corte Madera Creek Flood Risk Management Project

The project goals are to make improvements to Corte Madera Creek in Ross, Kentfield, & Larkspur by:

  • managing flood risk in a manner that is fully implementable and supportable by the local community by reducing the likelihood and consequences of flooding on human life & safety, and reducing the risk of flood damages;
  • preserving or restoring the natural creekbed and associated riparian habitat, and improving fish passage;
  • preserving or improving, to the extent practicable, the recreational experience & aestheic quality of Corte Madera Creek;
  • minimizing future erosion of unprotected creek banks & improving bank stability along the earthen channel in Ross; and,
  • minimizing long-term maintenance requirements of the project.

Project Location

View a map of the project study area (pdf)

The project is located along three reaches in Ross Valley and extends along San Anselmo Creek and Corte Madera Creek from:

  • Sir Francis Drake Blvd. bridge in Ross, under the Lagunitas Bridge to the upstream end of the concrete channel near the Ross Post Office (Unit 4)
  • The upstream end of the concrete channel in Ross, downstream through the College of Marin to the College Avenue Bridge in Kentfield (Unit 3)
  • The College Avenue Bridge, downstream past the Kent Middle School to the Bon Air Road Bridge in Larkspur (Unit 2)

Cost & Funding 

The preliminary cost estimate for Phase 1 is currently $13.5 million. Further development of the project details and project feasibility, along with further development of the entire project with USACE may result in an increased estimated cost. Present and future funding sources may include the Ross Valley Flood Control Zone 9 Storm Drainage Fee, US Army Corps of Engineers, California Department of Water Resources and other potential grant funding sources. 

Implementing Agency & Partners

Marin County Flood Control & Water Conservation District in partnership with the US Army Corps of Engineers and in cooperation with Ross, Kentfield, Greenbrae & Larkspur. 

Status & Next Steps

November 28, 2016 update & next steps

October 17, 2016 update & next steps

Both the larger Project and Phase 1 Project are in environmental review; it’s expected that a Draft EIR/EIS will be released for public review and comment in Spring 2018. The Final EIR should follow later in 2018 which offers another opportunity for public comment. The Phase 1 engineering and design will also include opportunities for public input.  Community input will continue to be a part of all phases of project development. 

Corte Madera Creek Flood Risk Management Project Status and Background

The Project is currently in the Feasibility Study phase and is being implemented under the US Army Corps of Engineers planning process. A number of conceptual measures have been identified that will be used to develop and compare project alternatives for achieving the project goals. 

On December 23, 2015, the environmental review process for the project began with the release of the Notice for the Preparation/Intent and Notice of Scoping Meeting of a joint Environmental Impact Statement/Report (EIS/EIR) for the project. This document includes a description of the project. A Public Scoping meeting was held on January 28, 2016 to describe the environmental review process, to provide an overview of the project and to take comments from the community on potential environmental effects to be addressed in the EIS/EIR. 

The Draft EIR/EIS will include descriptions of project alternatives that will be developed over the next several months by the project design team. Following the release of the Draft EIR/EIS, the public will have an opportunity to comment on these alternatives at a public hearing.  Notice will be sent to everyone on the mailing list indicating the availability of the Draft EIS/EIR and the time and location of the hearing. The public will be requested to conduct further review and provide additional comment on the alternatives prior to issuance of the final EIS/EIR. 

The environmental review process for this project was originally initiated in 2008.  As part of that prior effort, the US Army Corps of Engineers produced a 2010 Baseline Report that provided initial elements for the EIS/EIR and identified measures and project alternatives that were put forward at that time. This report, along with the Corte Madera Creek Project and Conceptual Measures posters and presentation slides shown at the January 2016 public scoping meeting, are meant to assist the public with their understanding of the proposed project by describing and illustrating the various conceptual project elements currently being considered.  Public scoping comments for the EIS/EIR should be focused on the potential environmental effects of these conceptual project elements and components. 

In order to provide everyone more time to send in comments on the project, the original comment period was extended from February 15 to March 1, 2016. This comment period is now closed.

Phase 1 Project Status

The Phase 1 Project is currently in a conceptual design phase and is being analyzed in the US Army Corps of Engineers planning and environmental review process. The final design and specific features of the project have not been completed at this point. The Marin County Flood Control and Water Conservation District (District) and Town of Ross are working together to conduct an in-depth public engagement process within the Ross community to ensure both directly and indirectly impacted residents have an opportunity to learn about the conceptual design and provide input early in the project development phase. The District is also carefully analyzing different scenarios to maximize flood reduction while supporting community interests and environmental benefits. 

It is expected that a Draft EIR/EIS will be released for public review and comment in Spring 2018. The Final EIR should follow later in 2018, which offers another opportunity for public comment. The Phase 1 final review will be engineering design and finally construction (projected to be complete by 2020).  Community input will continue to be a part of all phases of project development. 

As part of the project process, community input and public participation will be sought at many points through the life of the project. These are anticipated to include on-site, local neighborhood and broader community meetings led by the County, as well as public input and review meetings led by the US Army Corps and public meetings specifically required as part of the environmental review process. These opportunities will be advertised in advance to promote broad opportunity for participation. Receive notices about these and other meetings related to the Ross Valley Flood Protection & Watershed Program by providing us with your email address.

Preliminary Schedule(Pending project approval & Federal funding)

Project Phase

Typical Duration

Feasibility Study & Environmental Review

3 years

Real Estate & Final Design

2 years

Construction

1 to 2 years

Total Project Duration

6 to 7 years

Upcoming Meetings

December 19, 2017: 6-8p at College of Marin Deedy Staff Lounge (SS111) Granton Park neighborhood meeting on the Phase 1 project and flood preparedness efforts.

Past Public Meetings

Question & Answers Summary

December 14, 2017: Ross Town Council Meeting to consider support for continuing the process of feasibility and review of the Frederick Allen Park Riparian Corridor conceptual plan. This is a portion of Phase 1 of the Corte Madera Creek Flood Risk Management Project.

November 18, 2017 10:00a-12 noonJoin us for a Discussion and Site Tour of the proposed Frederick Allen Park Riparian Corridor conceptual plan. This is a portion of Phase 1 of the Corte Madera Creek Flood Risk Management Project.

November 4, 2017: Two neighborhood meetings with Sir Francis Drake, Poplar, and Sylvan residents and businesses to discuss conceptual Frederick Allen Park Riparian Corridor and removal of Ross Fish Ladder

October 10, 2017 7:00-9:00p at the Ross Town Council, District staff discussed latest plans to restore Allen Park Riparian Corridor which includes removal of Ross Fish Ladder. The meeting featured presentation slides of a draft conceptual plan

June 8, 2017: at the Ross Town Council, District staff presented changes to the Phoenix Lake IRWM grant Project and introduced options for reallocation of grant funds to other projects in Ross Valley, including 4 alternative options.

August 22, 2016 6:00-8:00p at the Ross School Gymnasium, Ross School, 9 Lagunitas Road, Ross. The US Army Corps of Engineers & Marin County Flood Control District held a community meeting to discuss the Corte Madera Flood Control Project, commonly referred to as Unit 4, Unit 3, and Unit 2. The meeting provided a presentation on the feasibility study and an opportunity for additional public input. 

April 25, 2016 5:30-7:30p at the Ross School Gymnasium. Congressman Jared Huffman, Supervisor Katie Rice, and the Army Corps of Engineers hosted a community discussion on proposed flood control projects in the Corte Madera Creek floodplain. The meeting provided an opportunity for additional public input and supplemental review of the scope of work for the proposed projects in the Corte Madera Creek, commonly referred to as Unit 4, Unit 3, and Unit 2. View the slide presentation and poster displays from this meeting.

April 20, 2016: Corte Madera Creek Walk. A group of interested people joined staff for a leisurely walk and information talk along the Army Corps Project area on Corte Madera Creek from Lagunitas Rd. to Kentfield Rehab area. 

January 28, 2016: About 70 community members gathered at the Marin Art and Garden Center to participate in a Public Scoping meeting and to provide public comments. Learn more on the NEPA/CEQA process. 

Scoping Meeting Agenda

Corte Madera Creek Project display

Conceptual Measures display

Slide presentation

Audio recording of the Public Scoping meeting is available on request

Comment Form (Word) (pdf)

Background Documents 

Feasibility Cost Sharing Agreement - MCFCWCD and USACE

USACE Corte Madera Creek Flood Control Study Baseline Report (December 2010)

USACE Project Map (from USACE project website)

Resolutions requesting USACE to proceed with lower level of design protection:

  • Zone 9 Advisory Board Resolution,dated 2/1/96

  • Marin County Board of Supervisors Resolution 96-26, dated 3/5/96 

Contact

The project manager for the Marin County Flood Control & Water Conservation District is Hugh Davis, P.E., Associate Civil Engineer (hdavis@marincounty.org). Receive notices about these and other meetings related to the Ross Valley Flood Protection & Watershed Program by providing us with your email address.

Background | Link to USACE Corte Madera Creek Flood Control Project website


Accessibility

If you are a person with a disability and require these documents in an alternate format (example: Braille, Large Print, Audiotape, CD-ROM), you may request an alternate format document by using the contact information below. If you require an accommodation (example: ASL Interpreter, reader, note taker) to participate in any county program, service or activity, you may request an accommodation by calling (415) 473-4381 (voice) / (415) 473-3232 (TTY) or by e-mail at disabilityaccess@co.marin.ca.us not less than four work days in advance of the event. 

Document File