Desiree Vineyard Conservation Agricultural Erosion Control Plan (ECP) - P24-00028

The project involves the conversion of approximately 16.7 gross acres of moderate to steeply sloped land, ranging from 18% to 34% grade, with 4.2 acres exceeding 30% slope, into a vineyard located at 5681 Silverado Trail in Yountville, California, on parcel APN 039-040-042-000. The development will clear 13.28 acres of coast live oak woodland and 2.24 acres of non-native annual grassland, resulting in approximately 13.1 net planted acres distributed across ten vineyard blocks, while permanently preserving 26.56 acres of existing coast live oak woodland. This environmental review is tied to Agricultural Erosion Control Plan P24-00028 and is subject to Napa County Code Chapter 18.108, requiring compliance with erosion and sediment control standards, including minimum vegetative cover thresholds of 80% to 90% depending on the block, installation of permanent no-till cover crops by October 15 of the initial development year, and certification by a qualified professional. The site lies within the Napa River Watershed-Yountville Reach and the Agricultural Preserve zoning district, accessed via a private driveway from Silverado Trail, and all activities must adhere to regional stormwater management guidelines, USDA-NRCS hydrologic modeling standards using SCS TR-20 and Curve Number methods, and strict controls on materials, equipment emissions, and site cleanliness. Performance and compliance obligations include implementing erosion controls during and after construction, obtaining all necessary permits at the contractor’s expense, contacting Underground Service Alert before excavation, maintaining a clean worksite, and furnishing utilities such as power and water. Equipment must use CARB-approved fuels and EPA SmartWay-certified trucks, with preference for electric or grid-powered tools and a ban on diesel idling beyond 10 hours per day. Recycling targets must exceed Title 24 requirements by 15%, with materials required to contain at least 20% recycled or locally sourced content and low-carbon concrete used where feasible. A two-year warranty covers all workmanship and materials. The project schedule spans multiple phases, including pre-planting activity from April to October, annual pruning in January, sulfuring three times between May and July, weed control applications from March to October, and harvest operations lasting eight days. Submissions for review must