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FRIDAY, SEPTEMBER 4, 2026 | SPECIAL REPORT & ANALYSIS
POLICY ANALYSIS | WOTUS & THE CLEAN WATER ACT
EPA, Army Reopen WOTUS Proposal Before Moving to Final Rule
Supplemental comment round targets wetlands, ditches and converted cropland
Analysis · September 4, 2026
EPA and the U.S. Army are taking an additional step before finalizing their new definition of “waters of the United States” (WOTUS), reopening a limited portion of the rulemaking for public comment to make the eventual regulation more durable under the Supreme Court’s 2023 Sackett v. EPA decision. For farmers and landowners, the move means another opportunity to influence some of the most consequential boundaries of federal Clean Water Act jurisdiction — but it also extends a regulatory process that has already lasted years.
What the supplemental notice does
EPA and the Army announced Sept. 4 (link) that they will issue a Supplemental Notice of Proposed Rulemaking, seeking comment on additional regulatory alternatives that will be considered alongside the WOTUS proposal issued in November 2025. The supplemental notice does not withdraw or replace that proposal. Once the new notice appears in the Federal Register, comments will be accepted for 30 days.
The November proposal was published in the Federal Register on Nov. 20, 2025, and drew more than 220,000 comments during a 45-day window that closed Jan. 5. “The EPA’s goal is a durable WOTUS definition that follows the law and ends burdensome regulatory uncertainty,” EPA Administrator Lee Zeldin said in announcing the supplemental round. Adam Telle, assistant secretary of the Army for civil works, said the Supreme Court’s Sackett decision “delivered the certainty our nation has been seeking for decades.”
Figure 1. Sackett to a final rule: the sequence that produced the Sept. 4 supplemental notice. Source: EPA and U.S. Army; Federal Register.
What the 2025 proposal would change
The underlying 2025 proposal would substantially clarify and in several areas narrow the circumstances under which wetlands, tributaries and other water features are federally regulated. Among other provisions, it proposed defining a “continuous surface connection” as requiring a wetland to abut — or physically touch — a jurisdictional water and have surface water at least during the wet season. It also proposed defining “relatively permanent” waters as those having standing or continuously flowing surface water year-round or at least during the wet season.
Those definitions are critical because the Supreme Court in Sackett rejected the broader “significant nexus” test and held that federal jurisdiction over adjacent wetlands requires a continuous surface connection to a qualifying water such that it is difficult to determine where the water ends and the wetland begins.
| PROVISION | WHAT THE 2025 PROPOSAL SAYS | WHY IT MATTERS IN AGRICULTURE |
| Relatively permanent | Standing or continuously flowing surface water year-round or at least during the wet season; features flowing only after rainfall are ephemeral and excluded. | Decides whether seasonal draws, sloughs and intermittent streams are federal water. |
| Continuous surface connection | A wetland must abut — touch — a jurisdictional water and hold surface water at least during the wet season. | Narrows adjacent-wetland jurisdiction across farmed landscapes. |
| Tributary | Relatively permanent flow with a bed and bank connecting downstream, directly or through culverts, pipes, dams or natural features. | Artificial conveyances do not automatically break a jurisdictional chain. |
| Ditches | Ditches, including roadside ditches, constructed or excavated entirely in dry land are excluded even if they carry relatively permanent flow. | Removes a long-running source of disputes at field and road edges. |
| Groundwater | Groundwater, including groundwater moving through subsurface drainage systems, is expressly excluded. | Confirms tile drainage sits outside federal jurisdiction. |
| Prior converted cropland | Exclusion continues unless the land is both abandoned for five years and has reverted to wetland. | Protects acreage converted for production before Dec. 23, 1985. |
| Interstate waters | The standalone interstate category is removed; every water must satisfy the Sackett two-part test. | Ends automatic jurisdiction based solely on crossing a state line. |
Table 1. Core provisions of the November 2025 WOTUS proposal. Source: EPA and U.S. Army proposed rule, Federal Register, Nov. 20, 2025.
EPA’s regulatory impact analysis estimated that roughly 19% of the wetlands mapped in the National Wetlands Inventory would qualify as waters of the United States under the November proposal.
For agriculture, several other pieces of the 2025 proposal are especially important. Ditches, including roadside ditches, constructed or excavated entirely in dry land would be excluded from WOTUS. Groundwater — including groundwater moving through subsurface drainage systems — also would be expressly excluded.
Figure 2. How the proposed exclusions and definitions would be applied to a water feature on farmland. Simplified for illustration; jurisdictional determinations are made case by case by the Army Corps of Engineers. Source: EPA and U.S. Army proposed rule.
Prior converted cropland
The proposal also provides a potentially important clarification for prior converted cropland. Land converted before Dec. 23, 1985, for agricultural production would remain excluded unless it is both abandoned and has reverted to wetlands. Abandonment would generally mean that the land had not been used for or in support of agriculture at least once during the preceding five years. Conservation uses, grazing, haying and other activities supporting agriculture could preserve the exclusion.
| TEST | EXCLUSION HOLDS | EXCLUSION IS AT RISK |
| Date of conversion | Converted for agricultural production before Dec. 23, 1985. | Converted on or after Dec. 23, 1985. |
| Use in the past five years | Cropping, grazing, haying, conservation-program enrollment or another use in support of agriculture at least once. | No use for or in support of agriculture for five consecutive years — “abandonment.” |
| Wetland conditions | Land has not reverted to wetland. | Land has reverted to wetland. |
| How the tests combine | Meeting either the use test or the wetland test preserves the exclusion. | The exclusion ends only when the land is both abandoned and reverted. |
Table 2. The two-part abandonment test for prior converted cropland as proposed. Source: EPA and U.S. Army proposed rule, Federal Register, Nov. 20, 2025.
Analysis & Perspective
The Sept. 4 action appears aimed less at fundamentally changing the direction of the rule than at strengthening its legal and administrative foundation. EPA and the Army have already received extensive comments, but several difficult questions remain — particularly how to translate Sackett phrases such as “relatively permanent” and “continuous surface connection” into language that can be applied consistently in farm fields, wetlands and drainage networks across widely different climates.
That is particularly important for the proposed “wet season” test. The 2025 proposal would allow seasonal waters to qualify as relatively permanent while generally excluding features that flow only following precipitation events. EPA acknowledged alternatives ranging from limiting jurisdiction to perennial waters to using a more traditional seasonal standard. The final choice could materially affect jurisdiction in the Plains and arid West, where drainage patterns differ significantly from those in wetter regions.
A regulatory patchwork
There is also a practical reason for EPA to seek a stronger final record: WOTUS remains a regulatory patchwork today. Because of litigation over the amended 2023 rule, EPA says that rule currently applies in 24 states, the District of Columbia and U.S. territories, while 26 states operate under the pre-2015 regulatory framework interpreted consistently with Sackett. A nationally applicable replacement would remove much of that state-by-state uncertainty.
Figure 3. Two federal standards, one country: states where the amended 2023 rule applies and states operating under the pre-2015 framework. Source: EPA rule status and litigation update.
For farmers, however, a narrower federal definition does not mean that every excluded wetland, ditch or seasonal stream becomes unregulated. Waters outside WOTUS can remain subject to state, Tribal or local requirements, meaning the practical regulatory effect will continue to vary geographically. The 2025 proposal itself emphasizes that states and Tribes retain authority over waters that do not qualify for federal jurisdiction.
Bottom line
The supplemental proposal signals that EPA and the Army are still headed toward a narrower, more specifically defined WOTUS standard built around Sackett, but they want another round of comments before locking in the final language.
For agriculture, the details to watch will be any changes involving wet-season flow, continuous surface connection, tributaries, farm and roadside ditches, and prior converted cropland. Those provisions will determine whether the final rule delivers substantially more predictable jurisdictional lines on agricultural land — and how well those lines hold up once the rule is implemented.
AG POLICY & MARKETS DAILY | POLICY ANALYSIS | WOTUS & THE CLEAN WATER ACT — FRIDAY, SEPTEMBER 4, 2026
