"Navigable Waters Protection Rule" Narrows Federal Clean Water Act Permitting Authority

On January 23, 2020, the U.S. Environmental Protection Agency and the Army Corps of Engineers finalized the Navigable Waters Protection (NWP) Rule, which redefines what waters are considered "navigable" and therefore regulated under the Clean Water Act (CWA). The final rule replaces the much-litigated Obama-era "Waters of the United States" (WOTUS) rule that was rescinded by the Trump administration in September 2019, as well as the case-specific "significant nexus" test enunciated by U.S. Supreme Court Justice Kennedy in Rapanos v. U.S. (2006) and subsequently issued agency guidance.

The NWP Rule substantially narrows the definition of "jurisdictional" waters to include only:

• Territorial seas and traditional navigable waters
• Perennial and intermittent tributaries that in a typical year flow to territorial seas and traditional navigable waters
• Wetlands that are directly adjacent to jurisdictional waters
• Lakes and ponds that are or contribute flow to navigable waters or are inundated by flooding from a jurisdictional water in a typical year and impoundments of jurisdictional waters

Excluded from federal jurisdiction are several categories of waters, including:

• Groundwater and surface water features connected only by groundwater to jurisdictional waters
• Interstate streams
• Ephemeral streams, swales, gullies, rills, and pools; i.e., that fill only in response to rainfall
• Diffuse stormwater run-off and sheet flow
• Many ditches, including most farm and roadside ditches
• Artificially irrigated areas and artificial ponds and lakes, such as farm and stock watering ponds
• Prior converted cropland
• Waste treatment systems

The NWP Rule becomes effective on March 23, 2020. Agricultural groups and the National Association of Home Builders have embraced the NWP Rule, praising its clarity and consistency. Environmental groups sued the Trump administration when it rescinded the WOTUS rule and a number are currently planning to take legal action against the NWP Rule.

For the time being, finalization of the NWP Rule means that the entire U.S. is now covered under a single regulation, whereas a welter of litigation had resulted in half the country being covered by the WOTUS rule and the other half operating under the predecessor to the WOTUS rule. However, it can be anticipated that the new rule will be vigorously contested nationwide, with the possibility that it will eventually come before the U.S. Supreme Court.

Most states, except for Idaho, Massachusetts, New Hampshire, and New Mexico, have been delegated CWA authority. Regulatory agencies in delegated states may continue to administer and enforce state regulations that define protected waters more broadly than the NWP Rule.