Public comment period extended for Nicasio Spillway Project Environmental Review Scoping

Updated May 15, 2025

NOTICE : Public Comment period extended, additional public meeting date added for Nicasio Spillway Modification Project's Environmental Review Scoping

Marin Water is extending the public comment period and adding another public scoping meeting for the proposed Nicasio Spillway Modification Project. The extension will allow more time to obtain suggestions and information from agencies and the public on the content and scope of issues to consider in developing the proposed project’s Environmental Impact Report, which Marin Water is initiating work on, pursuant to the California Environmental Quality Act.

The public comment period was originally scheduled to close on June 4, 2025 and will now close on August 4, 2025.
An additional virtual scoping meeting is now also being added to the schedule for July 15; this is in addition to the two scoping meetings that were already previously scheduled.

This webpage has been updated to reflect the changes in the public comment period schedule.

Pursuant to the California Environmental Quality Act, Marin Water is initiating the environmental review of the Nicasio Spillway Modification Project. Modifying Nicasio Reservoir’s spillway is one of the near-term storage enlargement projects identified through development of the District's Water Supply Roadmap.

The reservoir's current storage capacity is 22,340 acre-feet. This project would install a 280-foot-long, 4.4-foot-high inflatable rubber gate spanning the width of the existing spillway crest of Seeger Dam. The modification to the existing spillway would provide approximately 3,700 acre-feet of additional temporary water storage capacity. The Project would increase locally stored water supplies in the near-term to reduce adverse effects on Marin Water customers caused by water shortages from droughts and other emergencies.

The review process begins with a comment period for agencies and the public to comment on the scope of the environmental review, including the project description, environmental issues to be analyzed and potential alternatives. These issues are described in a Notice of Preparation.

Comment Period

The public comment period will be open from April 30, 2025 to 5 p.m. August 4, 2025. Comments must be submitted before the deadline and may be provided in one of the following ways:

By email to:
Elysha Irish
eirish@marinwater.org
Subject: Nicasio Spillway Modification Project public comment
By U.S. postal mail to:
Marin Water
Attention: Elysha Irish
220 Nellen Ave.
Corte Madera, CA 94925

Scoping Meetings

As part of the environmental review process, Marin Water is holding two public scoping meetings. These meetings are an opportunity for interested parties to learn more about the project and provide comments. The information presented will be the same for all three meetings.

Presentation for EIR Scoping Meetings

Scoping Meeting 1
Thursday, May 22, 6-8 p.m.

Scoping Meeting #1 Video Recording

Scoping Meeting 2
Tuesday, May 27, 1-3 p.m.

Scoping Meeting #2 Video Recording

Scoping Meeting 3
Tuesday, July 15, 1-3 p.m.

This meeting is online only:
https://marinwater.zoom.us/j/83247604594
Dial-in Number: 1-669-444-9171
Webinar ID: 832 4760 4594

Project Information and Background

Read the proposed project description and background on the Nicasio Spillway Modification Project page.