Please be advised that the County Stormwater Program is implementing the 2021 Regional Stormwater Permit, as of May 12, 2025.
The County Stormwater Program reviews proposed land development projects to prevent adverse impacts to the surface water quality and ensure compliance with requirements in the Los Angeles Regional Water Quality Control Board National Pollution Discharge Elimination System (NPDES) Municipal Separate Storm Sewer Systems (MS4) Permit, No. CAS004004 (Permit).
Forms
Industrial Facilities
County's Industrial Self-Certification for Stormwater Regulations 
form.
New Development and Redevelopment Projects Deemed Complete After May 11, 2025
NEW!2025 Technical Guidance Manual Tool (TGM Tool) 
NEW!2025 Technical Guidance Manual
New and Redevelopment Projects (2021 MS4 Permit)
2021 NPDES Permit No. CAS004004, Order No. R4-2021-0105 2021 Regional Permit
Stormwater Treatment Facility Maintenance Record Verification
New Development and Redevelopment Projects Deemed Complete Between October 11, 2011 and May 11, 2025
If your proposed project meets New Development or Redevelopment criteria of the
2010 Ventura County Stormwater Municipal Permit (Order No. R4-2010-0108) for the created, added, or replaced impervious or total surface area and was deemed complete after October 11, 2011, it shall address Permit requirements for post-construction stormwater controls described on Guidelines/Standards page documented in the following documentation:
- 2011 TGM Tool
This tool is used for the design of the PCSMP control systems. - Stormwater Treatment System Access and Maintenance Agreement
The information in this document will ensure on-going maintenance of the post-construction stormwater controls.
To verify proper maintenance and operation of post-construction stormwater controls, the project owner shall submit Stormwater Treatment Facility Maintenance Record Verification form each year by September 15th.
New Development and Redevelopment Deemed Complete Prior to October 11, 2011
If the proposed project meets New Development or Redevelopment criteria of the 2000 Ventura County Stormwater Municipal Permit (Order No. 00-108) for the created, added, or replaced impervious or total surface area, the proposed design shall address Permit requirements including Stormwater Quality Urban Impact Mitigation Plan (SQUIMP) to mitigate stormwater pollution. The project documentation shall include:
- Stormwater Treatment System Access and Maintenance Agreement
The information in this document will verify on-going maintenance of the post-construction stormwater.
To verify proper maintenance and operation of post-construction stormwater, the project owner shall submit Stormwater Treatment Facility Maintenance Record Verification form each year by September 15th.
Construction Requirements for all Projects
The following worksheet is required to identify stormwater best management practices required at construction sites.
For more information and resources regarding construction projects, please refer to the Guidelines/Standards page.
Brochures
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BMPs for Nurseries and Nursery Centers
This brochure presents Permit-required BMPs for nursery and nursery center operations to prevent stormwater pollution.
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BMPs for Auto-related Businesses
This brochure presents Permit-required BMPs for auto-related business operations (auto service, gas station, auto dealers).
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This brochure presents Permit-required BMPs for restaurant operations to prevent stormwater pollution.
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Illicit Discharge Prevention for Business Owners
This brochure describes what an illicit/illegal discharge is and how to prevent stormwater pollution.
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This brochure presents watershed protection tips for horse owners.
Guidelines / Standards
Industrial Business
Others
If your proposed project is determined to have impact on surface water quality or stormwater runoff, additional water quality mitigation measures may apply.
Laws/Ordinances
NEW!County of Ventura Stormwater Quality Management Ordinance for Unincorporated Areas
Policies
No policy information available at this time.
Fees
No fee information available at this time.
FAQs
No FAQs available at this time.
Contacts
County Stormwater Program
This email address is being protected from spambots. You need JavaScript enabled to view it.
Public Counter
Government Center
Hall of Administration,
Main Plaza
8:00 a.m. - 5:00 p.m.
(805) 645-1321