Section 401 Water Quality Certification Public Notice

Pilcaritos Dam Siphons Replacement Project

The San Francisco Regional Water Quality Control Board is currently reviewing an application for the following project for water quality certification under Section 401 of the Clean Water Act. We encourage public comments on the proposed work, which will be considered in the decision on certification. You may submit comments on this project to the staff member below.

Project Name:

Pilcaritos Dam Siphons Replacement Project

Unincorporated, San Mateo County
Comment Period:

5/21/2024 - 6/10/2024
Project Description:

The Pilarcitos Siphons, originally installed in 2011 and 2016, were damaged and broke apart in the winter storms of March 2023. Portions of the old siphons broke apart and drifted into the reservoir, while others were lodged in the spillway entrance, or downstream area of the spillway. Replacement siphons must be constructed to maintain the required environmental in-stream flows (1 to 2 cfs) and convey water downstream of Pilarcitos Dam when the reservoir elevation is below the spillway gate invert. It is critical that water be continuously released downstream of the dam to support endangered steelhead.
Project Files:

Contact Staff for files
Staff Contact:

Tahsa Sturgis
(510) 622-2316
Water Quality Control Board
1515 Clay Street, Ste 1400
Oakland, CA 94612