The Watershed Action Plan (WAP) for the Santa Ana Watershed Region of Riverside County (SAR) and its Permittees is a requirement of the Riverside County Municipal Separate Storm Sewer System (MS4), Permit Order No. R8-2010-0033 as adopted by the Santa Ana Regional Water Quality Control Board (Regional Board) in January 29, 2010 (2010 MS4 Permit). The purpose of this requirement is to coordinate existing watershed approaches to address water quality and hydromodification impacts resulting from urbanization within the SAR. This requirement is to be achieved by evaluating existing programs relating to the integration of water quality, stream protection, stormwater management, and re-use strategies with land planning policies, ordinances, and plans within each jurisdiction to the maximum extent practicable (MEP). Throughout implementation of the 2010 MS4 Permit along with the development of this plan, the Regional Board has emphasized that the plans for each jurisdiction should address cumulative impacts of development on vulnerable streams; preserve or restore, consistent with the MEP standard, the structure and function of streams; and protect surface water and groundwater quality.