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[NEW] 2025 TGM
This Technical Guidance Manual for Stormwater Quality Control Measures (2025 TGM) provides guidance for the implementation of stormwater management control measures in new development and redevelopment projects located in the County of Ventura and the incorporated cities therein. These guidelines have been developed to meet the Planning and Land Development requirements contained in the regional Phase I Municipal Separate Storm Sewer System (MS4) National Pollutant Discharge Elimination System (NPDES) Permit for stormwater and non-stormwater discharges from the MS4 within the coastal watersheds of Los Angeles and Ventura Counties (CAS004004, Order No. R4-2021-0105), henceforth referred to in this document as the 2021 MS4 Permit.
► 2025 TGM
► 2025 TGM Tool - An updated electronic tool to assist land development project applicants in meeting the new LID requirements under the new Permit. [To ensure you use the correct version of this tool always check with the agency that has jurisdiction over your project before starting. Links are provided at the bottom of this page.]
2025 TGM BMP Sizing Worksheets:
► Sizing_Worksheet_-_BIO-1_BIO-2.pdf
► Sizing_Worksheet_-_HM-1.pdf
► Sizing_Worksheet_-_HM-2.pdf
► Sizing_Worksheet_-_HM-3.pdf
► Sizing_Worksheet_-_INF-1_INF-2_INF-4.pdf
► Sizing_Worksheet_-_INF-3.pdf
► Sizing_Worksheet_-_INF-5.pdf
► Sizing_Worksheet_-_INF-7.pdf
► Sizing_Worksheet_-_PT-3.pdf
► Sizing_Worksheet_-_PT-4.pdf
► Sizing_Worksheet_-_RWH-1.pdf
TGM Errata Update 2018 Version
The 2015 TGM Errata Update was updated in 2018 to correct minor errors and unintentional omissions. Due to the evolving nature of stormwater quality management, the TGM may continue to be updated to correct errors, to incorporate new and innovative control measures, or to add the Hydromodification Control Plan.
► Errata Update TGM (June 2018)
► 2018 Errata Update Summary
► 2018 TGM Tool - An updated electronic tool to assist land development project applicants in meeting the new LID requirements under the new Permit. [To ensure you use the correct version of this tool always check with the agency that has jurisdiction over your project before starting. Links are provided at the bottom of this page.]
TGM Errata Update 2015 Version
The 2011 TGM was updated in 2015 to correct minor errors and unintentional omissions. Due to the evolving nature of stormwater quality management, the 2011 TGM may continue to be updated to correct errors, to incorporate new and innovative control measures, or to add the Hydromodification Control Plan.
► Errata TGM (May 2015)
► Errata Comments
The Technical Guidance Manual was approved by the Executive Officer of the LA Regional Board on July 13, 2011. The new rules became effective on October 11, 2011. For more information on how the effective date applies to projects see page 1-8 of the TGM.
► Final 2011 Technical Guidance Manual (July 2011)
► An electronic tool to assist land development project applicants in meeting the new LID requirements under the new Permit. [To ensure you use the correct version of this tool always check with the agency that has jurisdiction over your project before starting. Links are provided at the bottom of this page.]
► Ventura Stormwater Permit LID Alternative Compliance Stakeholder Meeting Announcement
► July 13, 2011 Approval Letter from Regional Board
Training Materials from June 21st, 2011, Seminar
►Morning Presentation (June 2011)
►Afternoon Presentation (June 2011)
►Flow Charts (June 2011)
Related Documents
►Final Technical Guidance Manual unapproved (November 2010)
►Transmittal letter to Regional Board (November 2010)
►Summary of comments and changes (November 2010)
►Effective date language (October 2010)
►Comment Letter - Calleguas Municipal Water District (October 2010)
►Comment Letter - City of Ventura (October 2010)
►Comment Letter - Contech (October 2010)
►Comment Letter - Jackson, DeMarco, Tidus & Peckenpaugh (October 2010)
►Comment Letter - Jensen Design (October 2010)
►Comment Letter - Natural Resources Defense Council & Heal the Bay (October 2010)
►Comment Letter - Paul Crabtree (October 2010)
►Comment Letters Summary (October 2010)
►Presentation - Rebecca Winer-Skonovd - TGM Revision, Step-by-Step Process (September 2010)
►Presentation - Lisa Austin - Land Development TGM Revisions (September 2010)
►Ventura County TGM for Stormwater Quality Control Measures (September 2010)
►Ventura County Technical Guidance Manual for Stormwater Quality Control Measures (May 2010)
►Presentation - Meeting Purpose and Objectives (January 2010)
►Presentation - Lisa Austin, Geosytnec Consultants (January 2010)
►Presentation - Rebecca Winer-Skonovd, Larry Walker Associates (January 2010)
►Meeting agenda (January 2010)
►Draft process flow chart (January 2010)
►Draft alternative compliance flow chart (January 2010)
►Draft outline of Technical Guidance Manual (January 2010)
Technical Guidance Manual (July 2002) - Applicable only to projects with applications deemed complete prior to the updated rule in 2011.