Waters of the U.S.

The Clean Water Act makes it unlawful for a person to add pollutants to a “water of the United States” without a permit.

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

In February 2017, President Trump signed an executive order directing the Environmental Protection Agency to rescind or revise the controversial "waters of the United States" (WOTUS) rule. EPA and the Army Corps of Engineers are now accepting comments on a new proposed rule. NAHB members can learn more and download sample comment letters on this page.

Home builders need a clear definition of what constitutes waters of the United States that does not encompass man-made systems or remote features with marginal ecologic value and is not beyond congressional intent of the Clean Water Act.

Why It Matters

When home builders need to add fill material into a water of the United States, they 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 Clean Water Act fill permit.

As the EPA and Corps expand the definition of “waters of the United States,” builders must obtain more permits, or more time and resources must be spent to avoid such features — and the current definitions aren’t clear as to precisely what to avoid.


  • The EPA and Corps should reconsider the rule in light of the legal guidance provided by the U.S. Supreme Court.
  • The term “waters of the United States” provides little direction to the EPA and Corps. Congress should develop a definition that is predictable and limited to protecting true aquatic resources.

See the latest on waters of the U.S. rule on NAHBNow.