The proposed project is a maintenance project to dredge accumulated mud and sediment in a 3,000-ft long by 40-ft wide (bottom width) trench along the length of the intake channel. The proposed project depth to negative six feet mean lower low water (MLLW)^1 with a two-ft overdredge is most similar to a previous maintenance dredge event in 1968, and would excavate ~ 41,600 cubic yards (cy) of sediment (which includes a 25% buffer) from the pump station intake channel. Figure 3 outlines the dredge limits from 1968 and 1987 along with the limits for the proposed project. On September 20, 2010 the Dredge Material Management Office (DMMO) advised that 26,000 cubic yards of sediment (which includes a 25% buffer) be disposed of in open water (SF-9) and that 15,600 cubic yards (which includes a 25% buffer) be disposed of at an approved upland location.
Water Facilities (for Mallard Slough Station Total acres: 2.75)(Intake Channel Type)
Other ActionOther Action: Operations & Maintenance Activity
Water QualityToxic/HazardousBiological ResourcesArchaeologic-Historic
Air Resources Board, Major Industrial ProjectsCalifornia Department of Parks and RecreationCalifornia Public Utilities CommissionCaltrans, District 4Caltrans, Division of AeronauticsCentral Valley Flood Protection BoardDelta Protection CommissionDepartment of Fish and Wildlife, Region 3Department of Toxic Substances ControlDepartment of Water ResourcesNative American Heritage CommissionOffice of Historic PreservationRegional Water Quality Control Bd., Region 5 (Sacramento)Resources AgencySan Francisco Bay Conservation and Development CommissionState Lands CommissionState Water Resources Control Board, Division of Water Quality