On February 7, 1979, the Napa County Planning Commission approved Use Permit Application U-147879 and thereby authorized use of the 24.26 acre property at 8338 St. Helena Hwy in unincorporated Napa County for a winery (Sequoia Grove Vineyards) with public tours and tastings and an annual production of 50,000 gallons of wine per year. In the years following that action, subsequent actions taken by the Napa County Board of Supervisors and Planning Commission authorized execution of a Williamson Act Contract on the property (Contract #377-82); winery building additions (Use Permit Modification U-108687); and addition of signage to the site (Sign Permit Po6-01342).
On February 6, 2008, the Planning Commission adopted a Subsequent Mitigated Negative Declaration (MND) and approved Major Modification to Use Permit, Application P07-00575, which authorized an increased in allowed wine production from 50,000 gallons to 150,000 gallons of wine per year, an increase from five to 30 employees, and legitimization of conversion of a single-family residence to winery office use. Other physical site improvements authorized by that approval included changes to on-site parking and septic and winery process wastewater treatment systems; construction of an approx. 2,190 sq. ft. addition to an existing administrative building; demolition of an existing, 691 sq. ft. office building; and construction of an approx. 13,796 sq. f.t winery production building with a basement plus two outdoor production areas and an adjoining, 1,638 sq. ft., covered receiving area. To date, only the wastewater treatment system improvements approved with P07-00575 - MOD have been installed on the property.
On April 18, 2016, the Napa County Zoning Administrator approved Minor Modification to Use Permit, Application P15-00239, a request by Sequoia Grove Winery for: 1) determination that P07-00575 - MOD had been exercised in accordance with Napa County Code subsection 18.124.080. A; and 2) approval of a minor modification to the use permit approval encompassed within P07-00575 - MOD, in order to change the footprint of the approved expansion to the administration building and replace the approved basement in the production building with an at-grade, covered fermentation building. Additional site improvements proposed with P15-00239 - MM included a covered terrace connecting the proposed administration building with the existing tasting room; reconfiguration of the approved outdoor, covered work areas; and addition of four, 14-foot diameter water storage tanks, a trash enclosure, a fire truck turnaround adjacent to the proposed new wine production structures, and a new access driveway from State Route 29. The request associated with P15-00239 - MM did not include any changes to visitation numbers, marketing events, employee counts, or the quantity of wine produced annually at the existing winery. In approving P15-00239 - MM, the Zoning Administrator adopted an Addendum to the 2008 Subsequent MND and determined that the environmental analysis and impacts identified int hat previously-adopted, Subsequent MND remain substantively unchanged by the site reconfiguration proposed with P15-00239-MM, and that the current project modification does not raise any new issues and does not exceed the level of significance of impacts identified in the 2008 Subsequent MND.