In late Februrary, President Trump signed an executive order to reconsider the Clean Water Rule, commonly known as the Waters of the United States (WOTUS) rule. Some claim the rule is needed to ensure water quality. On a closer look, the WOTUS rule has less to do with clean water and more to do with asserting federal authority over private land use.

The Clean Water Act of 1972 prohibits polluting the “navigable waters of the United States.” For decades, debate has raged over what is—and what isn’t —meant by “navigable.” The law does not provide a precise definition.

Waters of the U.S. were originally considered to mean waters that are navigable in fact—rivers, lakes, and large streams upon which one could navigate a water-going vessel. Federal regulation has since hinged on the Environmental Protection Agency’s (EPA) changing waters of the U.S. definition, with the Supreme Court holding the agency at bay each time it tried to recreate its own statutory authority.

The 2015 adoption of the WOTUS rule attempted to shed light on the key language in the Clean Water Act. Rather than clarify what waters are subject to federal jurisdiction, however, the new rule added more ambiguity and left landowners across the country vulnerable to unpredictable regulation.

The rule defines eight categories of waters of the U.S.

Six categories include traditional navigable waters, interstate waters, territorial seas (these three are called “jurisdictional waters”), impoundments of jurisdictional waters, “tributaries,” and “adjacent” waters. These are jurisdictional by rule in all cases, requiring no additional analysis in order to be regulated. To be adjacent, the rule uses the rubric of “neighboring,” which can be met by waters in the 100-year floodplain—meaning land which might be wet one out of every 100 days is a water of the U.S. and can be federally controlled. Texas coastal prairie wetlands are another type of water automatically considered adjacent, and therefore subject to regulation.

The final two categories can, upon “case-specific analysis,” be determined to have a “significant nexus” either alone or in combination with “similarly situated waters in the region.” The concept of a significant nexus was created by Supreme Court Justice Anthony Kennedy in 2006 and is not a scientific term, “but rather a determination made by the agencies.”

The WOTUS rule relies on the “connectivity gradient”—the idea that hydrologic connection of streams and wetlands to downstream waters shifts “in response to changes in natural and anthropogenic factors” and can “predict effects of different degrees of connectivity over time.” In other words, the ability to use one’s own land is dependent on the natural world, which exists in continual flux of countless and often misunderstood factors.

While the rule was intended to provide clearer standards, expansive rubrics like these further inconsistency, leading to what the late Justice Antonin Scalia referred to as the “‘Land Is Waters’ approach to federal jurisdiction.”

Section 3 of the new executive order calls for an interpretation of “navigable waters” in keeping with another of Justice Scalia’s opinions, where he argued that waters of the U.S. are “permanent, standing or continuously flowing bodies of water.” He noted that the Clean Water Act does not empower the EPA to “authorize intrusion into such an area of traditional state authority as land-use regulation,” nor “federal action that stretches the limits of Congress’ commerce power.”

Regulatory definitions should be crafted to facilitate consistent application, no matter who or what administration is enforcing it. The U.S. Constitution gives the legislative branch the authority to make laws, delegates agencies to implement laws in rule, and charges the executive branch with enforcing those rules. WOTUS’ interpretation of the Clean Water Act asserts expansive authority never anticipated by the federal law as enacted over forty years ago. Its reconsideration will make way for clearer expectations within which Texans and Americans alike can live, work, and create accordingly.

Megan Ingram serves as a Research Assistant with the Texas Public Policy Foundation’s Armstrong Center for Energy & the Environment.