Storm Water - Municipal Permits

The Los Angeles Water Board regulates discharges from medium and large municipal separate storm sewer systems (MS4s) through the Los Angeles County, Long Beach, and Ventura County MS4 Permits. These permits are issued under the National Pollutant Discharge Elimination System (NPDES) Program

Permits

Regional Permit

Los Angeles County (Historical)

Long Beach (Historical)

Ventura County (Historical)

Ventura County MS4 Permit Program Page

MS4 Items for Public Notice

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Posted Date	Comment Due Date	Permittee	Document	Associated Permit	Staff	Notice
Posted Date	Comment Due Date	Permittee	Document	Associated Permit	Staff	Notice
05/12/2025	06/11/2025	North Santa Monica Bay Coastal Watersheds	Notice of Opportunity for Public Comment on Request for Modification to the North Santa Monica Bay Coastal Watersheds CIMP	Regional MS4 Permit	Jessica Pearson	Public Notice
03/27/2025	04/28/2025	East San Gabriel Valley CIMP	Notice of Opportunity for Public Comment on Request for Modification to the East San Gabriel Valley CIMP	Regional MS4 Permit	Angineh Shahnazarian	Public Notice
03/11/2025	04/10/2025	Santa Monica Bay Jurisdictional Group 7	Notice of Public Comment on Request for CIMP Modification	Regional MS4 Permit	Angineh Shahnazarian	Public Notice
03/10/2025	04/03/2025	City of Whittier	Alternative Onsite Flow-based BMPs	Regional MS4 Permit	Susana Vargas	Public Notice
02/23/2024	03/25/2024	City of Whittier	Alternative Onsite Flow-based BMPs Approval Letter	Regional MS4 Permit	Susana Vargas	Public Notice
11/30/2023		All MS4 Permittees	Clarification Letter for Non-Stormwater Discharges from BMPs	Regional MS4 Permit	Jessica Pearson	The format of this letter has been changed to comply with Water Board web-posting requirements. If you wish to receive a copy of the original signed letter, please contact staff for the document.
09/29/2023	10/30/2023	City of South El Monte	Alternative Onsite Flow-based BMPs Approval Letter	Regional MS4 Permit	Susana Vargas	Public Notice
04/25/2023	05/24/2023	City of Diamond Bar	Alternative Onsite Flow-based BMPs Approval Letter	Regional MS4 Permit	Susana Vargas	Public Notice
01/31/2023	03/02/2023	City of Whittier	Alternative Onsite Flow-based BMPs Approval Letter	Regional MS4 Permit	Susana Vargas	Public Notice
04/19/2022	05/19/2022	City of Norwalk	Alternative Onsite Flow-based BMPS Contact staff for Approval Letter	Regional MS4 Permit	Susana Vargas	Public Notice

Showing 1 to 10 of 54 entries

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Written comments will be accepted through the Comment Due Date. Please email comments to the Staff contact and losangeles@waterboards.ca.gov. For more information please see the corresponding Notice.

Reporting Submittals and Permittee Websites

Watershed Management Program Progress Report Website(s)

Refer to the “WMP Reporting Website(s)” column in the table for the links.

Annual Reports (up to 2017-18 reporting period)
Monitoring Data (up to December 2018)
To request for any Annual Report and/or Monitoring Data submittals after the 2017-18 reporting period, please email MS4StormwaterRB4@waterboards.ca.gov

Storm Water - Municipal Permits

Permits

Regional Permit

Los Angeles County (Historical)

Long Beach (Historical)

Ventura County (Historical)

MS4 Items for Public Notice

Reporting Submittals and Permittee Websites

Resources

Contacts

Statewide Campaigns

Quick Links

Resources

Working with the Board