[Add Program Name Here] Program Logo

  1. Home
  2. water issues
  3. programs
  4. stormwater

Stormwater

Stormwater runoff is generated from rain (and snowmelt) events that flow over land or impervious surfaces, such as paved streets, parking lots, and building rooftops. The runoff can pick up pollutants like trash, chemicals, oils, and dirt/sediment that can harm the San Francisco Bay and other surface waters including rivers, streams, lakes, and coastal waters. To protect these resources, communities, construction companies, industries, and others, use stormwater controls, known as best management practices (BMPs). BMPs prevent pollution by controlling it at its source and/or remove pollutants by treating stormwater prior to discharge.

The Water Board regulates stormwater discharges under authorities of the federal Clean Water Act and California’s Porter-Cologne Water Quality Control Act. We issue National Pollutant Discharge Elimination System (NPDES) permits for stormwater discharges from four sources: municipal separate storm sewer systems (MS4s), industrial activities, construction activities, and California Department of Transportation (Caltrans) properties and facilities.

Announcements

Municipal Regional Stormwater NPDES Permit Reissuance

MRP 3 Adoption

The San Francisco Bay Regional Water Quality Control Board, at a hearing during its May 11, 2022, meeting, adopted a Revised Tentative Order, including revisions identified in Errata Sheets, a Supplemental, and presented orally during the hearing, to the Municipal Regional NPDES Stormwater Permit (MRP) covering municipal stormwater discharges from entities in Alameda, Contra Costa, San Mateo, Santa Clara, and Solano counties listed in the Order. The Adopted Order, Order No. R2-2022-0018, will replace the Permittees’ existing stormwater permit. The Adopted Order and documents posted during the permit reissuance process can be downloaded below under the Municipal Regional Permit Reissuance Tab.

Municipal Regional
Stormwater Permit

The Municipal Stormwater Program regulates stormwater discharges from municipal separate storm sewer systems (MS4s). An MS4 is a conveyance system designed to collect and convey stormwater that is owned by a city, town, or other public entity.

Urbanized areas increase stormwater runoff because impervious surfaces like roads, parking lots, and rooftops prevent stormwater from infiltrating, or soaking, into the ground. Urbanization also increases the variety and amount of pollutants in stormwater runoff. MS4s collect and convey this urban runoff and, in most cases, discharge directly to surface waters without treatment. Urban runoff contributes significant quantities of suspended solids, heavy metals, petroleum hydrocarbons, and other pollutants to surface waters of the region. However, if runoff is properly managed, those stormwater pollutants can be attenuated, and stormwater can be a valuable resource for uses such as groundwater recharge.

The Water Boards are actively involved in initiatives to improve the management of stormwater as a resource. Through permit requirements that promote low impact development (LID) techniques, green infrastructure (GI) planning, and other effective controls, we aim to prevent or minimize the discharge of pollutants contained in stormwater runoff to waters of the State.

Municipal Regional Permit

The Water Board issued county-wide municipal stormwater permits in the 1990s to all municipalities and flood management agencies in Alameda, Contra Costa, San Mateo, and Santa Clara counties, and within Solano County, the cities of Fairfield, Suisun City, and Vallejo, and the Vallejo Flood and Wastewater District. In 2009, the Water Board reissued these county-wide municipal stormwater permits as one Municipal Regional Stormwater NPDES Permit (MRP). The MRP (MRP 1)was reissued in 2015 (MRP 2)and again in 2022 (MRP 3). MRP 3 was amended in October 2023.

Important Note: The current permit, MRP 3, comprises Order Nos. R2-2022-0018 and R2-2023-0019. The following is an unofficial version of MRP 3 (without the Fact Sheet and other Attachments)that incorporates amendments to MRP 3 adopted in October 2023, and that has been compiled for convenience purposes only. Please refer to the adopted orders for a complete and accurate copy of MRP 3. In the event of a conflict between the adopted orders and this unofficial version of MRP 3, the adopted orders shall control.

Unofficial Version of MRP 3, Adopted in May 2022 and amended in October 2023

MRP 3 became effective on July 1, 2022 and is available here:

  • Municipal Regional Stormwater Permit, Order No. R2-2022-0018

    • MRP 3 was amended in October 2023; the amendment is available here:

  • Order No. R2-2023-0019

    • The previous permit, MRP 2, is available here:

  • Municipal Regional Stormwater Permit, Order No. R2-2015-0049, as amended by Order No. R2-2019-0004

    • For general inquiries, or to request copies of MRP Annual Reports, Green Infrastructure Plans, Water Quality Monitoring Reports, Direct Discharge Plans, or other submittals, please email our MRP inbox:

    RB2-MRP@waterboards.ca.gov

    Or, contact MRP staff directly:

  • Aidan Cecchetti at Aidan.Cecchetti@waterboards.ca.gov or (510) 622-3457
  • Imtiaz-Ali Kalyan at Imtiaz-ali.kalyan@waterboards.ca.gov or (510) 622-2499

    • MRP Permittee Stormwater Programs

    Alameda Countywide Clean Water Program - Association of 14 cities in Alameda County, together with Alameda County, the Alameda County Flood Control and Water Conservation District, and the Zone 7 Water Agency

    Contra Costa Clean Water Program - Association of 19 cities in Contra Costa County, together with Contra Costa County, and the Contra Costa Flood Control and Water Conservation District

    Fairfield-Suisun Urban Runoff Management Program

    Santa Clara Valley Urban Runoff Pollution Prevention Program - Association of 13 cities and towns in Santa Clara Valley, together with Santa Clara County and the Santa Clara Valley Water District

    San Mateo Countywide Water Pollution Prevention Program - Association of 20 cities and towns in San Mateo County, together with San Mateo County and the City/County Association of Governments

    Vallejo Flood and Wastewater District

    MRP 3 Adoption

    The San Francisco Bay Regional Water Quality Control Board, at a hearing during its May 11, 2022, meeting, adopted a Revised Tentative Order, including revisions identified in Errata Sheets #1 and #2, a Supplemental, and presented orally during the hearing, to the Municipal Regional NPDES Stormwater Permit (MRP) covering municipal stormwater discharges from entities in Alameda, Contra Costa, San Mateo, Santa Clara, and Solano counties listed in the Order. The Adopted Order, Order No. R2-2022-0018 (MRP 3) will replace the Permittees’ existing stormwater permit (MRP 2).

    The Adopted Order, Fact Sheet (Attachment A), and all other Attachments (B-I), are combined in the file linked below:

    Prior to adoption of the Order, a Tentative Order was posted for public review on September 10, 2021. The Water Board held a two-day public workshop hearing on October 12 and 13, 2021, where it received public comments on the Tentative Order. Written comments on the Tentative Order were accepted through November 16, 2021.

    Water Board staff posted a Revised Tentative Order and Response to Comments Received on April 11, 2022. Revisions to the Revised Tentative Order were identified in Errata Sheet #1 posted on April 26, 2022, Errata Sheet #2 posted on May 4, 2022, and a Supplemental posted on May 6, 2022. Additionally, revisions presented orally at the May 11, 2022, hearing were incorporated into the Adopted Order.

    The Tentative Order, Revised Tentative Order, Errata Sheets, Supplemental, and associated documents are linked below:

    If you have questions regarding this matter, please contact Derek Beauduy at (510) 622-2348 or via email to RB2-MRP@waterboards.ca.gov.

    The following video of a Bay Area Regional Collaborative Board meeting includes a presentation on the Municipal Regional Permit Reissuance (beginning at around 35 minutes). The presentation provides a status update from January 2021 and an overview of the focus on resilient green infrastructure. It is a resource on green infrastructure that the Regional Water Board staff believe to be informative, and the Board members may view it: Bay Area Regional Collaborative on 2021-01-15 10:00 AM.

      Contacts

    Municipal Stormwater Program

    Rebecca Nordenholt
    Rebecca.Nordenholt@waterboards.ca.gov
    Phone: (510) 622-1013

    Municipal Regional Permit Inquiries:
    RB2-MRP@waterboards.ca.gov

    Small & Non-Traditional MS4 Permit:
    Joseph Martinez,
    Joseph.Martinez@waterboards.ca.gov

    Industrial & Construction Stormwater Program
    Margaret (Maggie) Monahan
    Margaret.Monahan@waterboards.ca.gov
    Phone: (510) 622-2377

    Industrial & Construction General Permits Inquiries: R2stormwater@waterboards.ca.gov

    Caltrans
    Qi Yan, Qi.Yan@waterboards.ca.gov

      Subscribe to our Email Lists

    Quick Links