U.S. MS4 Needs Assessment Survey
WEF conducts the Municipal Separate Storm Sewer System (MS4) Needs Assessment Survey to track the challenges, drivers, and resource needs within the MS4 sector. This survey, conducted biennially, aims to:
- Identify MS4 program challenges and drivers.
- Determine information and technical resource needs.
- Estimate current funding levels and identify funding gaps.
The survey results help advocate for closing the funding gap and support the inclusion of stormwater as an independent infrastructure sector. The 2024 survey results will be published in the fall of 2026.
WEF’s goal is to reach as many MS4 communities (phase I, phase II, and non-traditional MS4 permitted programs) across the nation as possible while significantly representing all ten of the EPA regions and surpassing the previous interation of responses.
2022 MS4 Needs Assessment Survey Results
In late 2022 and early 2023, the WEF Stormwater Institute (SWI) surveyed municipal separate storm sewer system (MS4) permittees nationally. The primary objectives of this survey were to:

- Identify information and technical resource needs of MS4 permittees and to better understand MS4 stormwater program challenges.
- Estimate existing annual stormwater program budgets and the national funding gap in the stormwater sector.
- Highlight sector data in critical areas such as asset management, resilience planning, and the maturation of stormwater programs.
- Provide data and information to support the inclusion of stormwater as an independent infrastructure sector in the American Society of Civil Engineers (ASCE) Infrastructure Report Cardยฉ program.
The 2022 survey is the third such effort led by WEF since 2018, and now provides some opportunities for longitudinal data trend analysis. This survey iteration received 643 usable entries from 47 states, including the District of Columbia.
2020 MS4 Needs Assessment Survey Results

In the 2020 survey, WEF received 804 responses from 47 states, the District of Columbia, and Puerto Rico.
The WEF Stormwater Institute gratefully acknowledges the MS4 Survey Work Team for their contribution to the development and deployment of the survey and the analysis of the results.
2018 MS4 Needs Assessment Survey Results

In 2018, the WEF Stormwater Institute polled more than 600 MS4 permittees in the first attempt of its kind to identify common challenges and needs among the diverse array of U.S. stormwater managers. Results of the survey underscored broad needs for dedicated funding sources, infrastructure renewal or replacement, and clearer regulations among respondents.
- 2018 Survey Results – Executive Summary (September 2018)
- 2018 Survey Results – Full Report (May 2019)
For additional information or questions, please contact Lisa Deason at ldeason@wef.org.
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