Minor Alteration No. WA2023201 – Yolo Bypass Shag Slough Geotechnical Investigations

Minor Alteration No. WA2023201 involves geotechnical investigations for Reclamation District 2068 to evaluate stability and seepage at three locations along Shag Slough in Solano County, California. The scope of work includes conducting a maximum of 25 geotechnical explorations to a maximum depth of 60 feet, utilizing drilling borings and Cone Penetration Tests (CPTs) through the levee crown. These explorations will be situated between Levee Mile 3.2 and LM 5.5, with spacing of approximately 500 feet apart, to collect material properties and soil samples for laboratory analysis. The project is administered by the Central Valley Flood Protection Board and is designated as exempt from the California Environmental Quality Act (CEQA) under Class 6 for information collection. All activities must adhere to federal, state, and local engineering and environmental criteria, specifically following United States Army Corps of Engineers (USACE) standards and Office of Safety and Occupational Health standards. Primary points of contact for the project include Angela Nguyen-Tan of the Central Valley Flood Protection Board and Michael Moncrief, District Engineer for Reclamation District 2068.