Cost Reporting Tool

CASQA has developed a Cost Reporting Tool and companion User Manual to support CASQA members subject to NPDES Municipal Separate Stormwater Sewer System (MS4) Phase I and Traditional Phase II Permits to comply with the State Water Resource Control Board’s Final Standardized Cost Reporting Policy, adopted in January 2025. The cost reporting is required beginning with the July 1, 2026 – June 30, 2027 reporting year, as stipulated in 13383 Orders (expected Spring 2026).

Building on efforts in the San Francisco Bay Area, CASQA worked collaboratively with the Cost Reporting Work Group of 20+ member volunteers to develop the Tool and User Manual. CASQA also worked closely with the State Water Board STORMS unit to ensure consistency between CASQA’s Tool and User Manual and the State Water Board’s final Cost Reporting Guidance and MS4 Cost Data Portal.

The Cost Reporting Tool was developed as an Microsoft Excel Workbook with macros.

If you are an eligible member, access the Cost Reporting Tool, the tool User Manual, register for training workshops, and access past training workshops and materials by clicking the link below. You must be logged in as a CASQA member.

The California State Auditor’s Office (CSA) highlighted the need for standardized cost reporting guidance in a 2018 report titled “State and Regional Water Boards: They Must Do More to Ensure That Local Jurisdiction’s Costs to Reduce Storm Water Pollution Are Necessary and Appropriate.” CSA recommended that the State Water Board should develop statewide guidance on methods for tracking the cost of stormwater management, and adopt regulations necessary to ensure regional boards and local jurisdictions follow its guidance.

Based upon CSA’s recommendation, the Office of Research, Planning, and Performance (ORPP) published a guidance document for the Regional Water Quality Control Board’s staff (and the public) to obtain adequate, consistent, and comparable information regarding stormwater management costs related to the Phase I MS4 permit..

As an extension of this prior effort, State Water Board STORMS staff were tasked in 2020 to develop a regulatory approach to establish standardized cost reporting requirements for estimating, tracking, and reporting MS4 permit compliance costs. The State Water Board adopted a new policy on January 22, 2025 and will publish the Final Cost Accounting Guidance document (expected spring 2026) for the policy. The State Water Board will also release a new MS4 Cost Reporting Data Portal to which Phase I and Traditional Phase II MS4 permittees will begin uploading their annual cost reporting data within the same time frame as submitting their FY 26-27 Annual Reports.

More information can be found on the State Water Board website.