Section 401 Water Quality Certification Public Notice
1V840 SOL 37 PM 6.7-7.0 Emergency Flooding Repair
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: |
1V840 SOL 37 PM 6.7-7.0 Emergency Flooding Repair |
| City/County: |
Unincorporated, Solano County |
| Comment Period: |
10/29/2026 - 11/18/2026 |
| Project Description: |
South of the eastbound lane on SR37 from postmile 6.7 to 7.0 in Solano County, Caltrans has been experiencing abnormally high tidallyinfluenced water levels. During high tide events on at least four occasions since November 2025, water levels have topped and submerged the roadway, forcing crews to shut down traffic in both directions. In addition, water levels in Figueras Tract have not receded as previously observed, in an expected manner as predicted by tidal forecasts, or in a manner comparable to the northern and eastern parcels. During a recent minus tide stte vistt, water levels were observed almost level with the road (see minus tide photo). According to our maintenance managers, tidal closures of this nature have not been observed in recent memory (see the 2021 streetview image; same location as the minus tide). These abnormally high and prolonged tidal events have caused significant erosion of the RSP embankment protecting SR37, along wtth subsidence of the roadway and additional damage to the roadway ttself from tidal action and large debris. In hopes of identifying a source for the excess water levels, Caltrans also met with USFWS, which manages the southern parcel/Figueras Tract; observations of abnormally high water levels were corroborated, however, a point source for the issue could not be identified. |
| Project Files: |
Contact Staff for files |
| Staff Contact: |
Qi Yan (510) 622-2329 Water Quality Control Board 1515 Clay Street, Ste 1400 Oakland, CA 94612 |
