SCH Number 2026020935

Project Info

Title

Walnut Basin Project

Description

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.

2 documents in project