The EPA and Army Corps have published a supplemental proposal addressing the definition of "Waters of the United States" (WOTUS) under the Clean Water Act.

The agencies initially proposed a new WOTUS rule in November 2025. GCSAA raised concerns that several provisions would be difficult for golf course superintendents to understand and implement.

The supplemental proposal takes a different approach and addresses several of those concerns. Most importantly, it would establish clearer jurisdictional lines that could make it easier for superintendents to determine which waters are subject to federal Clean Water Act jurisdiction.

GCSAA supports the effort to provide greater clarity and certainty while continuing to evaluate several important implementation questions.

1. What are relatively permanent waters?

The supplemental proposal would generally limit “relatively permanent waters,” including rivers and streams, to perennial bodies of water. “Perennial” means standing or continuously flowing water every day of the year during ordinary conditions, subject to limited exceptions.

For superintendents, this represents a significant change from the earlier proposal. Rather than determining whether a stream flows during a particular “wet season” and identifying the appropriate tools and data needed to evaluate that flow, the supplemental proposal establishes a more readily understandable standard.

In practical terms, the proposal moves toward a perennial-water standard and generally excludes intermittent and ephemeral waters from the relatively permanent category, subject to specific exceptions. This is in alignment with the comments we submitted to the EPA earlier this year.  

2. What happens during a dry spell or drought?

The proposal recognizes that a perennial waterway can temporarily stop flowing without necessarily losing its WOTUS status.

For example, a waterway could remain perennial if it predictably dries up once during the year for no more than 30 consecutive days. GCSAA will evaluate whether the 30-day threshold and limitation to a single interruption provide a workable standard under real-world conditions.

The proposal also addresses extreme drought. An otherwise perennial waterway could retain its status despite an extended loss of flow during certain drought conditions. The agencies propose using specified drought classifications, including the U.S. Drought Monitor, to help make those determinations. A qualifying drought interruption could potentially last as long as five years.

GCSAA will examine whether these drought measures reflect conditions on the ground and provide superintendents with a practical way to determine when the exception applies.

3. What about ditches?

The supplemental proposal does not change the initial proposal’s treatment of ditches.

A ditch constructed or excavated entirely in dry land would be excluded from WOTUS even if it carries relatively permanent flow and connects to another WOTUS.

Importantly, the agencies would be responsible for establishing that a ditch was not constructed or excavated entirely in dry land. That could be particularly helpful for golf courses with drainage infrastructure that is 50, 75 or even 100 years old, where original engineering records may no longer exist.

GCSAA continues to support this clear and practical exclusion for ditches constructed or excavated in dry land.

4. What about wetlands?

The supplemental proposal also provides greater clarity regarding jurisdictional wetlands.

Generally, a wetland would need a continuous surface-water connection with a river, stream, lake or other water already considered a WOTUS. The proposal focuses on whether the connection makes it difficult to determine where the jurisdictional water ends and the wetland begins.

Greater clarity, but more work to do.

For years, GCSAA has advocated for a WOTUS definition that gives golf course superintendents a clearer understanding of where federal jurisdiction begins and ends.

The supplemental proposal represents meaningful progress. It moves away from the complicated “wet season” approach and toward criteria that should be easier for land managers to understand and apply.

But this remains a proposal. Questions remain about drought, temporary interruptions in flow, wetlands and other site-specific circumstances.

GCSAA will submit comments to help make the final rule as clear, practical and durable as possible for golf course superintendents.

Here is a copy of the supplemental proposed rule.