Priority Development Project Infiltration Infeasibility Documentation Guidelines

This letter provides information to clarify the California Regional Water Quality Control Board, San Diego Region's (San Diego Water Board) expectation on the types of documentation needed to support a storm water infiltration infeasibility determination made by a Copermittee during the development planning project approval process. The San Diego Water Board would review such supporting documentation during a storm water municipal program audit of the development planning infiltration and retention requirements in the National Pollutant Discharge Elimination System Permit and Waste Discharge Requirements for Discharges from the Municipal Separate Storm Sewer Systems Draining the Watersheds within the San Diego Region (Regional MS4 Permit).