Waters of the U.S.

The Clean Water Act (CWA) makes it unlawful for a person to add pollutants or dredge or fill material into a "water of the United States" (WOTUS) without a permit.

Since 1972, determining which water bodies are waters of the United States has been the subject of federal agency regulations, guidance and numerous cases both at the U.S. Supreme Court and at the lower federal courts.

Now, roughly half of the country is subject to one set of regulations while the other half must comply with different requirements.

On Dec. 11, 2018, the Trump administration proposed a new WOTUS definition to replace the controversial 2015 rule that went so far as to regulate man-made ditches and isolated ponds on private property. The proposed rule is more consistent with Congressional intent for the CWA and court opinions, and should be easier to implement because it bases jurisdiction on observable, surface water connections. Further, the proposed rule provides needed clarity by excluding "emphemeral features" that form only in response to rainfall. The comment period for the proposed rule closed on April 15, 2019.

NAHB, state and local associations, and members worked extensively with the EPA and Corps of Engineers (Corps) during the comment period to provide feedback for the final rule. We will continue to monitor the administration's progress in finalizing the rule and keep members informed of important developments.

Why It Matters

When home builders need to add fill material into a water of the United States, they must first get a permit from the Corps. Obtaining permits is costly and time consuming. For example, one study found that it costs on average $270,000 and takes 788 days to obtain an individual CWA fill permit.

As the EPA and Corps expanded the definition of "waters of the United States," builders needed to obtain additional or more onerous permits, spending more time and resources to avoid wet features — this has been made all the more difficult because existing regulations do not clearly define which features to avoid.


  • The EPA and Corps should move quickly to end regulatory uncertainty by rescinding the 2015 rule and replacing it with the newly proposed definition. 

For the latest WOTUS information, visit NAHBNow.