Napa River/Napa Creek Flood Protection Project Geotechnical Explorations - Increment 3

The Napa County Flood Control and Water Conservation District is seeking geotechnical explorations for the Napa River/Napa Creek Flood Protection Project - Increment 3. This preparatory project involves collecting critical data to inform the design of floodwalls along the west bank of the Napa River in the City of Napa, specifically from Imola Avenue in the south to the intersection of Brown Street and Riverside Drive in the north. The scope of work includes the execution of approximately 13 borings and 9 cone penetration tests, each advanced to a depth of roughly 60 feet or until refusal. These activities are scheduled to take place between September and November 2025, subject to weather and coordination with local landowners and the City of Napa. The project is categorized as exempt under CEQA Sections 15304 and 15306 due to its minor, temporary, and localized nature. Strict environmental and safety protocols are required, including the use of a qualified biologist for wildlife and nesting bird clearance surveys within 24 hours of starting investigations. The contract mandates adherence to inadvertent discovery protocols for cultural resources, requiring an SOI-qualified archaeologist to oversee finds and strict compliance with the California Health and Safety Code regarding human remains. Additionally, the project requires site-specific health and safety plans, wildfire prevention measures, and adherence to federal and state water discharge requirements using best management practices. Personnel requirements include a driller or CPT operator, assistants, a utility locator, and a geologist or engineer for logging.