160 Franz Valley School Road Erosion Control Plan Application (ECPA) #P25-00235-ECPA

The project involves the development of 2.3 gross acres of new vineyard, with 2.1 net planted acres, located on a 20.36-acre parcel at 160 Franz Valley School Road in Calistoga, California. Managed by Napa County under application P25-00235-ECPA, the scope of work includes clearing non-native annual grassland and mixed oak woodland, earthmoving, and the installation of both temporary and permanent erosion and runoff control measures. The project is situated within an Agricultural Watershed zone and includes a 4.6-acre preservation area and the retention of 13.9 acres of oak woodland. Technical compliance is supported by a Water Availability Analysis to ensure groundwater sustainability and a soil loss analysis using the Universal Soil Loss Equation to ensure post-project sediment delivery does not exceed pre-project levels. Hydrologic analysis was conducted using USDA Technical Release 55 and NOAA Atlas 14 data to evaluate peak storm flows. Environmental safeguards include a Mitigated Negative Declaration under CEQA and specific biological mitigation measures to protect nesting birds, raptors, and roosting bats. A biological assessment confirmed that the site lacks suitable habitat for the Northern Spotted Owl, requiring no seasonal restrictions for that species. The project is overseen by Planner III Kelli Cahill and follows a structured implementation schedule to meet Napa County's conservation and planning standards.