On May 12, 2025, the Los Angeles Regional Water Quality Board issued an approval letter of the Ventura Countywide Stormwater Quality Management Program Group’s Watershed Management Program (WMP). The approval letter clarifies compliance metrics for Water Body-Pollutant Combinations and specifies additional requirements including requirements for the adaptive management process. The Minimum Control Measures as defined in the 2021 Regional MS4 Permit became effective with the approval of the WMP (May 12, 2025).
