Minor Alteration No. WA2025118 – Irrigation Pipe Maintenance at RD 2064 Unit 2 LM 4.24 Project

Minor Alteration No. WA2025118 involves the irrigation pipe maintenance project at Reclamation District 2064 Unit 2, located at levee mile 4.2 along the right bank of the Stanislaus River in San Joaquin County, California. The primary objective is the in-kind replacement of an existing Corrugated Metal Pipe (CMP) pipeline and associated equipment with new steel piping featuring poly wrapping. The scope of work includes removing the old pipeline, installing a positive closure device on the waterside hinge, clearing and grubbing vegetation, and replacing the access road in kind. Construction activities will involve ground disturbance by heavy equipment and concrete trucks along the levee crown and slopes, with excavation reaching a depth of 3.2 feet below the design water surface elevation. Technical execution requires backfilling around and under the pipe using Controlled Low Strength Material (CLSM) or approved native material placed in 4-inch to 6-inch lifts. All backfill must be compacted to a relative compaction of 90% per ASTM D1557-91, and the project must undergo pipe leakage testing. All work must adhere to California Code of Regulations, Title 23, Waters, Division 1 standards and the Standard Operations and Maintenance Manual (O&M SJR003). The project is statutorily exempt under CEQA as it constitutes maintenance and minor alterations without expansion of use. The Central Valley Flood Protection Board serves as the approving agency, with Reclamation District 2064 acting as the project applicant.