De-Silting of Creek Bed Diversion Site and Ongoing Diversion (Notification of Lake or Streambed Alteration, No. EPIMS-NAP-54985-R3)

The California Department of Fish and Wildlife (CDFW) has executed Lake and Streambed Alteration Agreement EPIMS Notification No. EPIMS-NAP-54985-R3, pursuant to section 1602 of the Fish and Game Code to Robert Sinskey. The Project is limited to 1) removing accumulated silt ranging in depth from one to six feet over an area of approximately 13,000 square feet (0.298 acres), on the unnamed tributary when water is not present, no more than once per year for the term of the Agreement; and 2) the ongoing operation of water diversion structures in compliance with water rights issued by the California State Water Resources Control Board (Application 15807 and 301512), in addition to conditions provided by CDFW in this Agreement. Water is collected at an onstream reservoir on the unnamed tributary to the Napa River (henceforth referred to as Reservoir 1) using a concrete weir structure with a gated outlet near the bottom. Water is transferred to a remote reservoir on the same property (Reservoir 2) with an electric pump that is seasonally lowered into Reservoir 1. During the diversion, excess sediment has accumulated in Reservoir 1, blocking the gated outlet running under the weir. The de-silting is needed for diversion activities to continue, to restore Reservoir 1 to permitted capacity, to maintain flows to downstream ecosystems, and to avoid flooding hazards and damage to the surrounding property. One back-hoe tractor and crews using shovels will remove silt and load it onto a trailer, then haul it to an on-property pasture and seeded with an erosion control cover crop for later grazing by livestock. The backhoe and crews will utilize a single existing access road for the point of entry and exit to Reservoir 1. The riparian area surrounding Reservoir 1 is composed of mixed native and non-native vegetation and will not be disturbed. No trees will be removed as a result of the Project. The Project will result in approximately 13,000 square feet (0.298 acres) of temporary impacts and 450 linear feet of temporary impacts resulting from the removal of a maximum of approximately 1,685 cubic yards of dry silt per year. Material to be removed will be limited to dry silt, not including woody or rocky streambed features or stream cobble. The Project will remove the minimum amount of dry silt needed to restore functionality to the water diversion structures. The Project will not damage or remove riparian vegetation occurring along the bank of the stream.