The Fight Over the 'Waters of the U.S.' Rule: What You Need to Know

The Waters of the U.S. rule, which the Trump administration is planning to undo, improves federal protection for about 22 million acres of wetlands in the contiguous U.S., as well as upwards of two million miles of streams. Credit: Getty Images

On Wednesday the U.S. Environmental Protection Agency and the Army Corps of Engineers released a proposal to rollback the Waters of the U.S. rule, or WOTUS. Finalized by the Obama administration in 2015, the rule tackled a long-standing ambiguity in the original Clean Water Act — where state, local, or private oversight of a wetland or small waterway ends and federal jurisdiction begins.

In 1972 Congress defined the Clean Water Act's scope as covering “traditionally navigable waters of the United States,” but has never defined that further, leading to decades of confusion and disputes over how far into upstream tributaries and watersheds federal clean water rules apply. 

WOTUS added new protective measures to smaller water bodies that provide drinking water for around 117 million people. While the rule was widely popular in opinion polls, farming, mining, and drilling interest groups bitterly opposed it. A U.S. Court of Appeals blocked implementation of the rule a few months after it was finalized, pending resolution of the many lawsuits filed against it. Among the litigants: then-Oklahoma attorney general and current EPA Administrator Scott Pruitt.

While the battle will likely continue in lawsuits and the courtroom of public opinion (a 30-day public comment period will start soon at epa.gov/wotus-rule), the actual terms of the rule could easily be lost in rhetoric. Here's what it does:

1. Acknowledges Downstream Pollution 

WOTUS defines a “tributary” under the Clean Water Act as “a water that contributes flow, either directly or through another water [to] a traditional navigable water, territorial sea, or interstate water,” extending protection to smaller waterways and water bodies. What matters under this rule is how connected a water body is — not its size or whether it flows year-round.

2. Protects Wetlands, Streams

Many wetlands weren't clearly covered under the Clean Water Act because they aren't necessarily "navigable." WOTUS improves federal protection for about 22 million acres of wetlands in the contiguous U.S., as well as upwards of 2 million miles of streams and some small, isolated bodies of water, such as the shallow wetlands of the Prairie Pothole Region of the Great Plains.

3. Lets Irrigation Ditches and Farm Ponds Be

WOTUS does not regulate groundwater, nor does it increase federal oversight of irrigation or drainage ditches — two of many objections leveled at it by opponents, who have filed upwards of three dozen lawsuits to block the rule from taking effect. These and many other small water bodies — like farm and stock ponds —are exempted from the Clean Water Act.