Stormwater Issues & Policies to Keep an Eye on in 2023

March 21, 2023
NMSA Executive Director Seth Brown highlights a few policies to pay attention to this year.

As the new year starts and planning begins for many of you on projects and program initiatives, it is easy to lose sight of high-level policy issues in our sector. With this in mind, here are a few of the more dynamic policies to keep on your radar in 2023. 

Stormwater Centers of Excellence for Stormwater Infrastructure Technologies 

The omnibus package passed by Congress late in 2022 and signed into law by President Biden on December 23, 2022, included appropriations for a stormwater provision that has been in legislation in one form or another since 2011 or before. This provision is for the establishment of between three and five Centers of Excellence for Stormwater Infrastructure Technologies (CESITs). The omnibus package specifically appropriated funds of $3 million, out of the authorized $5 million, to be used annually over the next five years to support these CESITs. The next step will be for EPA to go through the process of determining how these centers will be established and administered. The funding of the CESITs should be considered as a major victory for the stormwater sector as it represents the first stormwater-only provision in the Infrastructure Bill that has received appropriated (and not just authorized) funds.   

Waters of the U.S. 

The game of volleyball that has been played on the issue of the defining the Waters of the U.S. (WOTUS) continues with the latest iteration being a rulemaking that was recently completed by EPA and the U.S. Army Corps of Engineers (USACE) and will go into effect in early March 2023. As stated by EPA, the rule, “returns to a reasonable and familiar framework founded on the pre-2015 definition with updates to reflect existing Supreme Court decisions, the latest science, and the agencies’ technical expertise.”   

At the onset of the rulemaking process in August 2021, EPA suggested that this rulemaking would likely occur as a two-step process. The first step, which is the one they have just completed, was referred to as a "foundational rule" to "restore the regulations defining 'water of the United States' that were in place for decades until 2015.” The second step was stated to be a "rulemaking process that further refines and builds upon that regulatory foundation".   

Efforts were made by stormwater groups, such as the National Municipal Stormwater Alliance (NMSA), to ensure that this first step would include a categorical exclusion to remove that stormwater control features in the definition of a WOTUS in this rule. This exclusion has been part of previous versions of the WOTUS definition, and it is significant to our sector to ensure that stormwater infrastructure, which is increasingly nature-based, will never be considered as a WOTUS. Without this exclusion, there could be significant confusion in situations where stormwater infrastructure may seem to function similarly to wetlands and other protected waters. This confusion could lead to costly delays in time and money for localities and those who wish to implement stormwater infrastructure projects and need to perform essential O&M functions efficiently. We should be finding ways to reduce barriers to constructing nature-based stormwater infrastructure – an unclear WOTUS definition will not be helpful in this goal. It is not entirely unexpected that this exclusion was not included in the recent final rule, as EPA and the USACE signaled that refinements in the rule would likely occur in the second step. We expect – and hope – that this exclusion will be included in the second step in the rulemaking process.    

Census Criteria & MS4 Designations 

Starting with the 2020 Census, the terms “urbanized area” and “urban cluster” are no longer in use. Instead, the Census will use the term “urban area,” with a population number associated with each area. EPA relied on the term “urbanized area” in the 1999 Federal Rule that defined communities to be regulated under the MS4 permitting program, so the change required a rule revision. On December 3, 2022, EPA published a two-track rule revision in the Federal Register to accomplish this change – a “direct final rule” and a normal proposed rule, both with identical rule revisions. EPA proposes to replace the term ‘‘urbanized area’’ in the MS4 Phase II regulations with the phrase ‘‘urban areas with a population of at least 50,000.” The “direct final rule” will proceed if EPA receives no adverse comments, with the rule revisions taking effect in early March 2023. If EPA receives any adverse comments, they will withdraw the “direct final rule” and the normal rulemaking will proceed. 

EPA has signaled that the proposed change is intended to maintain the status quo in the program. While the change is not likely to be impactful overall, there may be isolated instances where the change may lead to uncertainty on how designations are made for some communities.   

A Dynamic National Landscape 

The three issues highlighted above reflect the evolving nature of the stormwater sector at the federal level. NMSA has been engaged in all of these topics and intended to remain engaged in these, and other, issues of significance. As stormwater continues to rise in significance, it is anticipated that stormwater issues at the national level will become even more dynamic.   

If you would like to learn more about NMSA and the activities of this organization on national-level policies, please go to   

Seth Brown is executive director of NMSA. Brown can be reached at [email protected].

Note: The author would like to thank Randy Neprash, NMSA vice chair, for his input on this article. 

About the Author

Seth Brown

Seth Brown has over 25 years of experience in the water sector and is the Principal and Founder of Storm and Stream Solutions, LLC, a consulting firm providing a range of services from policy and alternative project delivery analysis in the stormwater sector to facilitation and training services focused on stormwater topics.   He was the Director of Stormwater Programs at the Water Environment Federation from 2010-2015 and is currently the Executive Director of the National Municipal Stormwater Alliance, which is a 501.c.3 representing stormwater-focused organizations in 24 states across 9 of the 10 U.S. EPA regions with a network that is comprised of over 4,000 MS4s. 

Seth has a Ph.D. in civil engineering from George Mason University with a research focus on socio-economic modeling of incentive-based investments of green stormwater infrastructure on private properties.  He leads courses in Green Infrastructure and Innovative Water Partnerships at Virginia Tech and the University of Maryland at Eastern Shore and is a licensed professional engineer in the state of Maryland.   

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