About Stormwater & Urban Runoff 

Stormwater is precipitation, including rain, hail, and snow. Urban runoff is stormwater that doesn’t seep into the ground but ‘runs off’ through streets, parking lots, and other parts of the storm drain system, eventually flowing into the nearest stream, creek, river, lake, or ocean. The runoff is not treated in any way.

Unlike the sewer system, which carries water from indoor drains to wastewater treatment plants, the storm drain system in the City of Perris releases untreated water into flood control channels, the San Jacinto River, Canyon Lake, and ultimately Lake Elsinore.

Stormwater Pollution 

Stormwater pollution is everything, seen and unseen, mixed with stormwater. As stormwater passes through the network of streets and drains, it picks up everything along the way, including trash, debris, metals, sediment, and many unseen pollutants. Unlike the sewer system, this polluted stormwater receives no treatment and flows directly into our local streams and rivers. 

Communities must address the impacts of stormwater runoff as part of the Environmental Protection Agency's (EPA) National Pollutant Discharge Elimination System (NPDES).

NPDES Program

In 1972, the United States Congress passed amendments that significantly enhanced the federal laws governing water pollution in the United States. These and subsequent amendments comprise the Clean Water Act (CWA), which establishes a framework for regulating municipal and industrial (including construction) stormwater discharges under the National Pollutant Discharge Elimination System (NPDES) permit. Section 402(p) of the CWA requires NPDES permits for stormwater discharges from municipal separate storm sewer systems (MS4), as well as other designated stormwater discharges that are considered significant contributors of pollutants to the waters of the United States. 

On January 29, 2010, the Santa Ana Regional Water Quality Control Board (SARWQCB) issued a 4th-term area-wide National Pollutant Discharge Elimination System (NPDES) and Municipal Separate Storm Sewer System Permit (MS4 Permit) to the City of Perris and all Permittees. The Santa Ana MS4 Permit is for the Santa Ana River watershed portion located within Riverside County  (Order No. R8-2010-0033, NPDES Permit No. CAS618033).

The Permittees’ stormwater programs are designed to ensure compliance with this permit. 

The City of Perris’ stormwater programs are designed to ensure compliance with this permit. All design submittals and construction projects are required to conform to the permit requirements. All projects must install Best Management Practices (BMPs) in compliance with the 2010 SARWQCB permit.

Public Outreach

In order to protect and preserve our lakes, channels, and streams, we all have to do our part! The following brochures provide tips and requirements (aka Best Management Practices or (BMPs)) that can be used in daily activities to reduce pollutants, and help keep lakes and streams clean. Please note that illegal discharges are subject to enforcement actions, including fines.

If you need additional information about National Pollutant Discharge Elimination System (NPDES) regulations, Best Management Practices, please see the following web links:

View the Water Quality Guidance Documents and Templates

Master Project Specific Water Quality Management Plan Template

Low Impact Development Manual

NPDES-related inquiries and/or concerns can be emailed to NPDES@cityofperris.org.

Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Windows Media Player Word Viewer Excel Viewer PowerPoint Viewer