Riverside County Watershed Protection

Santa Margarita River Watershed

Diamond Valley Lake

Santa Margarita River Watershed Protection Program

The Santa Margarita River Watershed flows into the Santa Margarita River, passing through southwest portion of Riverside County (including areas of the Cities of Menifee, Murrieta, Wildomar, and unincorporated County of Riverside, and all of the City of Temecula)  into San Diego County.

Stormwater runoff from these areas collects into Murrieta and Temecula creeks and combines to form the Santa Margarita River in Temecula. The Santa Margarita River flows through the “Gorge” and into San Diego County where it flows past Camp Pendleton into the Santa Margarita Lagoon at the Pacific Ocean. The Santa Margarita ‘Region’ is the portion of the Watershed that is within Riverside County. 

Member Agencies

The Riverside County Flood Control and Water Conservation District is the Principal Permittee of the Santa Margarita MS4 Permit.

Compliance Documents

Benefit Assessments

Benefit Assessments are apportioned on the basis of proportionate stormwater runoff generated by each parcel. This method of assessment is consistent with State law and the District Act. The amount of benefit is computed based on parcel size (acreage) and use classification. The fee is referenced on property tax bills as “FLDCNTL Stormwater/clean water.”

For questions regarding the Stormwater Benefit Assessment Fees, please contact the Riverside County Flood Control & Water Conservation District at: 951-955-1200.

Santa Margarita River Watershed’s Engineer’s Report:

Santa Margarita River Watershed

Applications & Forms

General Forms

Upper Santa Margarita River Watershed Stormwater Resource Plan Forms

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