National Municipal Separate Storm Sewer System (MS4) Needs Assessment Survey

2022 National Municipal Separate Storm Sewer System (MS4) Needs Assessment Survey – The survey is now closed and we are working on developing the report

WEF’s Stormwater Institute (SWI) is on a mission to better understand the challenges, drivers, and resource needs across the MS4 sector. As such, SWI launched its third iteration of the National Municipal Separate Storm Sewer System (MS4) Needs Assessment Survey which was originally established in 2018 to collect on a biannual basis. The primary objectives of the survey are to:

  • better understand MS4 program challenges and drivers,
  • identify the information and resource needs of MS4 permittees, and
  • approximate current funding levels and estimated funding needs in the MS4 sector.

The target audience of the survey is:

  • MS4 Permittee holders
  • Program Managers that manage their client’s MS4 Permit

The impact of this survey ranges from advocating with our partner organizations for:

WEF’s Stormwater Institute goal is to reach as many MS4 communities (phase I, phase II, and non-traditional MS4 permits) across the nation as possible, have the results significantly represent all 10 EPA regions, and surpass our previous responses. 

Click here to learn more about the questions we asked during the 2022 iteration.


2020 National Municipal Separate Storm Sewer System (MS4) Needs Assessment Survey Results Report

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, as well as the analysis of the results.

Clink on the following link to access the 2020 National MS4 Needs Assessment Survey Results Report (Published on February 2021).

In addition to the report, several supporting appendices are available below:

The second iteration of the MS4 Needs Assessment survey provided a Data Dashboard feature that enables users to filter data by permittee type, geographic region, and other characteristics. The dashboard has the goal of improving the understanding of the challenges, needs, and drivers for stormwater programs. The Data Dashboard is powered by 2NDNATURE Software.

June 3, 2021 Webcast Recording – WEF MS4 Survey and Dashboard: Stormwater Data Coming Alive

2018 National 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 sources of funding, infrastructure renewal or replacement, and clearer regulations among respondents.

2018 Survey Results – Executive Summary (September 2018)

2018 Survey Results – Full Report (May 2019)

Press Release: First-Ever Stormwater Needs Survey Shows $7.5 Billion Annual Funding Gap (May 2019)

If you would like any additional information or have questions, please email Bianca Pinto at