The first-ever analysis of needs of the U.S. stormwater sector shows an estimated $7.5 billion annual funding gap and revealed top priorities and challenges across the country.

The inaugural MS4 Needs Assessment Survey led by the Water Environment Federation’s Stormwater Institute, reflects an effort to learn more about the nature and needs of the municipal separate storm sewer system (MS4) sector at a scale that has never been attempted. 

The survey generated some significant findings:

• Phase I and II (municipal and nontraditional) permittees ranked regulatory compliance, local flooding and water quality and habitat restoration issues as important program drivers.  

• The most significant challenges as identified are lack of funding, aging infrastructure and evolving regulations.  

• Respondents indicated the greatest need for information and technical resources is related to funding and financing. In addition, there is a need for technical information and products on green infrastructure practices and innovative techniques/technologies, as well as information related to asset management.  

 • An unexpected finding is the lack of priority by respondents regarding climate change, which points to the need to highlight how changing precipitation patterns will impact MS4s in the future. 

“An important first step in a maturing infrastructure sector is to better understand the fundamental challenges and needs,” says WEF Executive Director Eileen O’Neill. “This survey and analysis represent this first major step in the stormwater sector, which is a field that is notoriously data-poor. By collecting data on the MS4 sector, this effort identifies the priorities that need to be addressed in the near term while allowing for planning for coverage of other areas in a long-term strategic fashion.” 

The survey received 622 responses from 48 states and the District of Columbia. Approximately 25% and 65% of respondents represented Phase I and II MS4 permittees, respectively. Non-traditional Phase II permittees and state transportation departments accounted for 7% and 3% of the survey sample, respectively. This statistically significant sample is also generally representative of the distribution of MS4s across the U.S., according to WEF.

Stormwater is the only growing source of water pollution in many waterways across the country, according to WEF. With urban populations expected to grow to nearly 70 percent by 2050, and more frequent and intense storms occurring across the country, there is ever-increasing pressure on stormwater systems and water infrastructure.