Napa Valley Marina Dredging (Notification of Lake or Streambed Alteration, No. EPIMS-NAP-49159-R3)

The California Department of Fish and Wildlife (CDFW) has executed Lake and Streambed Alteration Agreement EPIMS Notification No. EPIMS-NAP-49159-R3, pursuant to section 1602 of the Fish and Game Code to Napa Valley Marina. The Project is limited to conducting dredging during the environmental work window of August 1 to October 15 when temperatures throughout the water column exceed 22 degrees Celsius (i.e., when longfin smelt (Spirichus thaleichthys) and other special-status fishes are not expect to occur in the Project area) at five locations within the Napa Valley Marina. In total, up to 83,800 cubic yards of sediment will be removed from an approximately 11.88-acre area Specifically, dredging will be conducted using an IMS Dredge, Model 6008, using a cutter suction (i.e., hydraulic) dredge with a hood mounted on a 44-foot barge. The dredge pump’s maximum efficiency is approximately 910 gallons per minute. The area will be dredged to a depth of -11 feet Mean Lower Low Water (MLLW), which includes one-foot over-dredge . Dredging spoils will be transported through an eight-inch pipeline starting at the barge and ending at the settling basin on the Napa Sea Ranch property (Exhibit A). The pipeline will temporarily span Carneros Creek by laying it by hand on the ground surface and via an approximately four-foot-wide temporary metal footbridge installed by hand. The pipeline and footbridge will be removed immediately upon completion of the Project. Dredging spoils will be tested and disposed of in accordance with Dredge Material Management Office (DMMO) standards, and if consistent with these standards, deposited into a settling basin on the Napa Sea Ranch property, located immediately north of Carneros Creek. Dredging activities within the Napa Valley Marina were previously included in CDFW Agreement No. EPIMS-NAP-20435-R3, issued in 2021 with an expiration date of December 31, 2025. The activities described above to be covered by EPIMS-NAP-49159 will continue with the same dredging equipment over an expanded dredging area within the Napa Valley Marina.