Section 401 Water Quality Certification Public Notice
Crystal Springs Road Emergency Culvert 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: |
Crystal Springs Road Emergency Culvert Repair |
| City/County: |
Unincorporated, San Mateo County |
| Comment Period: |
2/10/2026 - 03/2/2026 |
| Project Description: |
This culvert required replacement due to corrosion inside the pipe, which caused erosion around the pipe. An intermittent, unnamed drainage flows through the culvert. In Summer 2025, the culvert was identified in need of maintenance due to a debris jam plugging the culvert at high flows. Based on the location of the pipe under the Hwy 280 bridge, the County conferred with CalTrans to identify maintenance responsibilities for the culvert. In October 2025, the County began efforts to flush the pipe and address some erosion on the adjacent road shoulder from previous culvert overtopping events. The work was included in the County’s Routine Maintenance Program list of non-reporting, non-ground distrubing activities. CCTV footage of the culvert, captured on November 18, 2025 during flushing activities, revealed that the pipe was severely deteriorated beyond the debris jam. The bottom of the pipe was rusted out and beginning to erode the ground below. Given the high volume of water the culvert receives from Hwy 280 runoff, continuing efforts to fully flush the pipe without also repairing the pipe would have lead to continued erosion under the pipe and risked causing a sinkhole and subsequent failure of the roadway. The pipe overtopped and flooded the roadway during the November 12, 2025 atmospheric river, further emphasizing the need for immediate repair. The pipe continued to overtop and bypass resulting in further erosion during the most recent late December/early January storm event. |
| Project Files: |
Contact Staff for files |
| Staff Contact: |
Jackson Fimrite (510) 622-2310 Water Quality Control Board 1515 Clay Street, Ste 1400 Oakland, CA 94612 |
