Geotechnical Investigations for the Sunset Weir and Pumps Fish Passage Project

The Geotechnical Investigations for the Sunset Weir and Pumps Fish Passage Project, identified as Minor Alteration No. WA2025031, involves critical subsurface exploration to support the design of the Sunset Weir and Pumps Fish Passage Project, which includes the removal of the Sunset Weir. Located in Sutter and Yuba Counties, California, near the existing Sunset Weir approximately 2.25 miles southeast of Live Oak, the work entails drilling nine geotechnical borings along the right bank levee and floodway of the Feather River. These borings will reach a maximum depth of 120 feet or refusal, utilizing standard penetration tests to collect soil samples. Additionally, two of the nine borings will undergo Seismic Cone Penetration Testing. To ensure site integrity, all boreholes must be backfilled on the same day of drilling using a tremie to place a mixture of cement and cuttings to the required depth. The project scope includes necessary construction activities such as clearing and grubbing existing vegetation within the floodway and ground disturbance facilitated by a truck-mounted drill rig. The Central Valley Flood Protection Board serves as the approving agency, with the Department of Water Resources acting as the lead agency. This project has been granted a Notice of Exemption from the California Environmental Quality Act (CEQA) under categorical exemptions for information collection and minor alterations to land, as the activities are classified as basic data collection with minimal environmental impact. Administrative oversight is provided by Jordan Robbins of the Central Valley Flood Protection Board and Rachel Ballanti of the Department of Water Resources.