Walnut Basin Project

Walnut Basin Project

The City of Hesperia (City) is proposing the construction of a new sediment and debris basin to improve flood control and sediment management in the downtown area of the city of Hesperia (city/Hesperia) (project). The project area is located along Main Street in Hesperia, in San Bernardino County (County), approximately 0.2 mile west from the intersection of 11th Avenue and Main Street. The proposed sediment and debris basin would consist of a primary trapezoidal sloped inlet facility on the south end of the basin at Walnut Street and include access roads around the basin as well as a maintenance road that extends into the bottom of the basin to allow for basin maintenance and sediment removal. The sediment and debris basin is designed to provide approximately 23,000 cubic yards (14.26 acre-feet) of debris storage, with erosion control rip rap, maintenance access roads, and an outlet structure that would connect to the existing dual 10-foot-diameter pipes. The sediment and debris basin would be designed to reduce runoff velocities and flow capacities, allowing sediment to settle from runoff prior to entering the storm drain system. In addition, a 5-foot-high stabilized earth berms would be designed to convey flows through the sediment and debris basin and allow for sediment deposit. The sediment and debris basin would be 24 feet deep with a 3-foot-deep concrete spillway to convey the flows into the existing dual storm drain pipes. A low flow outlet would be provided at the base of the spillway to convey small storm drain events and to drain the sediment and debris basin after a storm event.

Hesperia

San Bernardino

Citywide

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Inland Deserts Region 6 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 8 (DOT), California Department of Water Resources (DWR), California Fish and Game Commission (CDFGC), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Public Utilities Commission (CPUC), California Regional Water Quality Control Board, Lahontan Victorville Region 6 (RWQCB), Colorado River Board, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Water Quality, State Water Resources Control Board, Divison of Financial Assistance

Water Facilities (Drainage Basin)(Type Drainage Basin, MGD 1)

Public Infrastructure

Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Flood Plain/Flooding, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Schools/Universities, Solid Waste, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire