Minor Alteration No. WA2025097 – Sycamore Mutual Water Company Pipe Replacement Project

The project proposes to remove and replace in-kind an 18-inch diameter steel drainage discharge pipe from the pump beyond the landside toe, through the levee, and down to the outlet on the waterside, above mean high water (MHW). The project proposes to include a positive closure device on the landside shoulder and a siphon breaker on the waterside of the levee. Excavation through the levee will occur just above the Design Water Surface Elevation (DWSE), however excavation on both landside and waterside will be within 10 feet of the levee toe and will penetrate the projected levee slope. The excavation through the crown will be backfilled using Controlled Low-Strength Material (CLSM), the excavation on the levee slopes will be backfilled with native material and compacted, and the levee crown roadway will be restored with compacted Class II aggregate base. The drainage discharge pipe is authorized under Permit 9390.