San Diego Region - Riverside County Municipal Storm Water Permit

ORDER NO. R9-2013-0001, AS AMENDED BY ORDER NO. R9-2015-0100

The California Regional Water Quality Control Board, San Diego Region (San Diego Water Board) adopted Order No. R9-2015-0100, an Order Amending Order No. R9-2013-0001, NPDES No. CAS010266, as Amended by Order No. R9-2015-0001, National Pollutant Discharge Elimination System (NPDES) Permit and Waste Discharge Requirements for Discharges from the Municipal Separate Storm Sewer Systems (MS4s) Draining the Watersheds within the San Diego Region at its November 18, 2015 Board Meeting. The attachments to Order No. R9-2015-0100 identify specific changes made to Order No. R9-2013-0001 and Fact Sheet in blue underline and red-strikeout text. The conformed copy of Order No. R9-2013-0001 and Fact Sheet incorporates all adopted changes.

Final Documents

Public Hearing

The Public Hearing on Tentative Order No. R9-2015-0100 was held during the San Diego Water Board meeting scheduled for November 18, 2015. More information on the Public Hearing is found in the Notice of Opportunity to Comment and Public Hearing.

Public Comments on Tentative Order No. R9-2015-0100

The San Diego Water Board received the following written comments on the Tentative Order and proposed changes to the Regional MS4 Permit:


On February 11, 2015, the San Diego Water Board adopted Order No. R9-2015-0001, which amended Order No. R9-2013-0001, to extend coverage of the Regional MS4 Permit to the Orange County Copermittees and address a variety of other issues. During the proceedings for Order No. R9-2015-0001, the San Diego Water Board deferred consideration of two concepts proposed as permit amendments to establish 1) a definition of the term "prior lawful approval" for priority development projects, and 2) an alternative compliance pathway that would conditionally allow the Copermittees to be deemed in compliance with the receiving water limitations and related prohibitions of the Regional MS4 Permit. The San Diego Water Board scheduled a series of workshops to receive comments and information from the Copermittees and other key stakeholder groups concerning the prior lawful approval and alternative compliance pathway issues.


In accordance with Section F.1.h of Order No. R9-2010-0016, the  Riverside County Copermittees submitted a draft Hydromodification Management Plan (HMP) for the Santa Margarita Region of Riverside County on July 1, 2013. 

Model Water Quality Management Plan

In accordance with Section F.1 of Order R9-2010-0016, on July 9, 2012 the County of Riverside submitted a Water Quality Management Plan (Model WQMP) for the Santa Margarita Region of Riverside County to the San Diego Water Board Executive Officer.

Final Documents

November 10, 2010 Public Hearing

Notice of Public Meeting for October 13, 2010-09-08

Notice of Written Comment Period

The San Diego Water Board hereby notifies the public that Tentative Order No. R9-2010-0016, the reissuance of the Riverside County MS4 Permit, is available for review and public comment. Written Comments on Tentative Order No. R9-2010-0016 must be received by 5:00 p.m. on September 7, 2010. The Tentative Order, Attachments, Monitoring and Reporting Program and Fact Sheet are available below:

Riverside County MS4 Permit R9-2004-0001

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Additional Information

The following Websites can provide further information related to urban runoff and the Santa Margarita Watershed.

  (Page last updated 5/11/18)