Waters of the United States Definition: Sackett Test and Exclusions

The definition of “waters of the United States” (WOTUS) sets which rivers, streams, lakes, ponds, and wetlands fall under federal Clean Water Act authority and which do not. Under 33 CFR 328.3, as rewritten after the Supreme Court’s 2023 decision in Sackett v. EPA, the definition covers five categories: traditional navigable waters tied to interstate or foreign commerce (including tidal waters), the territorial seas, interstate waters, impoundments of any of those, relatively permanent tributaries that flow into them, and wetlands with a continuous surface connection to those waters. Intrastate lakes and ponds qualify only when they are relatively permanent and share a continuous surface connection with a covered water.¹ If a water feature on your land fits one of those categories, federal permitting applies before you fill, dredge, or discharge into it.

The Five Categories of Covered Waters

The Clean Water Act defines “navigable waters” as “the waters of the United States, including the territorial seas.”² The regulations translate that phrase into five specific categories.

The first is waters used, or susceptible to use, in interstate or foreign commerce, including all waters subject to the ebb and flow of the tide. These are the traditional navigable waters. The second is the territorial seas. The third is interstate waters, meaning waters that cross state lines. Together these three form the core of federal jurisdiction and have never been seriously contested.

The fourth category is impoundments of any of the above, such as reservoirs and dammed lakes, which qualify on their own once created. The fifth extends jurisdiction to tributaries feeding the core waters, but only tributaries that are “relatively permanent, standing or continuously flowing.” Wetlands adjacent to any of these waters can also qualify, and intrastate lakes and ponds can qualify, but each of these depends on tests the Supreme Court sharpened in 2023.¹

How Sackett Tightened the Test for Wetlands and Streams

Before 2023, regulators could reach a wetland if it had a “significant nexus” to downstream navigable waters, meaning it influenced the chemical, physical, or biological integrity of those waters. That standard is gone. In Sackett v. EPA, the Supreme Court held that the Clean Water Act reaches “only those wetlands that are ‘as a practical matter indistinguishable from waters of the United States.'”³

The current wetland test has two parts. First, the water body next to the wetland must itself qualify as WOTUS, meaning it has to be a relatively permanent body of water connected to a traditional navigable water. Second, the wetland must have a continuous surface connection with that water body, “making it difficult to determine where the ‘water’ ends and the ‘wetland’ begins.”³ A wetland cut off from a protected water by a berm, dike, levee, road, or strip of dry ground generally fails the test, even if it plays a real ecological role in downstream water quality.

For streams, the Court adopted a similar “relatively permanent” standard. Only “relatively permanent, standing or continuously flowing bodies of water ‘forming geographical features’ that are described in ordinary parlance as ‘streams, oceans, rivers, and lakes'” count as waters under the Act.³ Ephemeral channels that only carry water during and shortly after rainfall generally fall outside federal jurisdiction. Seasonal streams that flow for months at a time can still qualify, depending on how consistently they hold flow.

EPA has removed all “significant nexus” language from 33 CFR 328.3 to line the regulations up with Sackett.¹ The question is no longer whether a wetland ecologically affects a downstream water. The question is whether it is physically, visibly, continuously connected at the surface to a relatively permanent water.

What the Definition Explicitly Leaves Out

The regulations list features that are not WOTUS even when they look like protected waters. These exclusions matter because they mark the ground where a federal permit is not required.

Waste treatment systems, including treatment ponds and lagoons designed to meet Clean Water Act requirements.¹
Prior converted cropland: land drained or manipulated for agricultural production before December 23, 1985, and designated as such by the Secretary of Agriculture. The exclusion ends if the land is abandoned for agricultural purposes and reverts to wetland conditions.
Ditches dug entirely in dry land that drain only dry land and do not carry a relatively permanent flow. Roadside and agricultural drainage ditches that only run water during or right after rain typically fit here.
Artificially irrigated areas that would revert to dry land if irrigation stopped.
Artificial ponds and water features built by digging or diking dry land, including stock ponds, irrigation ponds, settling basins, reflecting pools, swimming pools, and small ornamental features.
Water-filled depressions incidental to construction, and pits dug to obtain fill or gravel, unless the site is abandoned and the resulting water body qualifies as WOTUS on its own.

A caveat that trips people up: a ditch created by rerouting a natural stream can still be regulated. The dry-land exclusion turns on whether the channel was carved out of dry ground or built by moving an existing waterway.

The Agricultural Recapture Trap

Section 404(f) of the Clean Water Act exempts certain farming, ranching, and forestry activities from Section 404 permitting. A “recapture” provision, though, pulls that exemption back when two conditions are both met: the activity converts a water feature to a new use, and it reduces the reach or impairs the flow of waters of the United States.⁴ Converting wetland rangeland into row-crop production, for instance, is both a change of use and a reduction in wetland reach, so it triggers the permit requirement even though it looks like ordinary farming.

What It Means If Your Water Feature Qualifies

Falling within any WOTUS category triggers two federal permitting regimes. Section 402 governs pollutant discharges from identifiable sources such as pipes and outfalls under the National Pollutant Discharge Elimination System.⁵ Section 404, run primarily by the U.S. Army Corps of Engineers, covers the discharge of dredged or fill material.⁶ Filling, grading, piping, or otherwise disturbing a WOTUS feature without the right permit is illegal.

Penalties are stiff. The statutory civil penalty is up to $25,000 per day per violation under 33 U.S.C. § 1319(d), and the inflation-adjusted amount now runs well above that baseline. Because penalties are assessed daily, an unpermitted fill project that continues for weeks can generate six-figure liability.⁷

Criminal penalties scale with intent. Negligent violations carry fines of $2,500 to $25,000 per day and up to one year in prison. Knowing violations run $5,000 to $50,000 per day and up to three years, with maximums doubling on a second conviction. Knowing endangerment, where the violator knowingly places another person in imminent danger of death or serious injury, carries fines up to $250,000 for an individual and up to 15 years in prison.⁷

Getting a Definitive Answer for Your Property

The Army Corps of Engineers issues two kinds of jurisdictional determinations, and which one you want depends on whether you need speed or certainty.

Preliminary Jurisdictional Determination

A preliminary jurisdictional determination (PJD) is advisory. The Corps identifies and maps every aquatic resource on the property and treats each one as if it were jurisdictional, without ruling on whether it actually is. That lets you move directly into permitting. PJDs are faster and simpler, which makes sense when you know you will need a permit anyway. They cannot be appealed and give you no definitive answer on the legal status of any feature.⁸

Approved Jurisdictional Determination

An approved jurisdictional determination (AJD) is the binding ruling. It formally establishes whether jurisdictional waters exist on your property, maps their boundaries, and stays valid for five years from the date of issuance. During that window the Corps cannot reverse its position absent new information.⁸ This is the option to use when the jurisdictional question is what you actually need answered, particularly if you believe a feature on your land falls outside federal reach after Sackett.

To request an AJD, submit a request form to your local Corps District office with a site map, property location details, and any existing surveys. In most cases you also need a professional wetland delineation report prepared under the 1987 Wetland Delineation Manual and the appropriate regional supplement, with sub-meter GPS data, soil and vegetation analysis, and mapping that meets Corps standards.⁹ Hiring an environmental consultant for that report typically costs several thousand dollars or more depending on site size and complexity. The Corps then reviews the file, usually schedules a site visit, and issues a determination. Processing commonly takes 60 to 120 days, longer for complex sites.

If You Disagree With the Result

You can file an administrative appeal of an AJD with the division engineer within 60 days of receiving the notification. The review officer evaluates the record and may conduct a site visit within 60 days of accepting the appeal, and the division engineer normally issues a final decision within 90 days of receipt. The entire appeal process cannot exceed 12 months. You can also submit new information to the district engineer within the same 60-day window and ask for reconsideration, which is sometimes a faster path.¹⁰

Non-WOTUS Doesn’t Mean Unregulated

Confirming that a water feature is not WOTUS is not the end of the analysis. Many states regulate wetlands and waterways under their own laws, and some state programs cover features that the federal definition leaves out.

Under Section 401 of the Clean Water Act, states also review federal permit applications to certify that the permitted discharge will comply with state water quality standards. A state can grant certification, attach conditions, or deny it outright and block the federal permit. States must act within a reasonable period not exceeding one year; failure to act waives the certification requirement.¹¹

Beyond Section 401, some states run independent wetland permitting programs that reach further than the federal rules. After Sackett narrowed federal jurisdiction, those state programs became the primary backstop for wetlands that lost WOTUS status. Other states rely entirely on federal regulation, so wetlands falling outside WOTUS have no protection at all in those jurisdictions. Check your state’s environmental agency before assuming a non-WOTUS feature is unregulated.

A Proposed Rule May Shift the Definition Again

On November 17, 2025, EPA and the Department of the Army announced a proposed rule to further update the WOTUS definition.¹² The proposal works within Sackett’s framework but tries to clarify several exclusions.

The proposal would formally define “prior converted cropland” in the regulation itself and specify that abandonment occurs when the land goes unused for agricultural purposes for five consecutive years.¹³ It would revise the ditch exclusion to require excluded ditches to be “constructed or excavated entirely in dry land,” and it would expressly exclude groundwater, including groundwater drained through subsurface tile drainage systems. The proposal also seeks to reestablish an easier route for farmers to obtain prior converted cropland determinations for Clean Water Act purposes rather than relying solely on USDA designations.

Whether the rule is finalized, and in what form, is still open. Until then, the post-Sackett text at 33 CFR 328.3 is the operative definition, and every question about what is covered on your property runs through it.

1
eCFR. 33 CFR 328.3 – Definitions
2
Office of the Law Revision Counsel. 33 USC 1362 – Definitions
3
Supreme Court of the United States. Sackett v. EPA, No. 21-454
4
U.S. Army Corps of Engineers. Information Regarding Compliance with the Federal Clean Water Act Section 404(f) Provisions
5
Office of the Law Revision Counsel. 33 USC 1342 – National Pollutant Discharge Elimination System
6
U.S. Environmental Protection Agency. Permit Program under CWA Section 404
7
Office of the Law Revision Counsel. 33 USC 1319 – Enforcement
8
U.S. Army Corps of Engineers Honolulu District. Jurisdictional Determinations
9
U.S. Army Corps of Engineers Sacramento District. Aquatic Resources Delineation Minimum Standards
10
eCFR. 33 CFR Part 331 – Administrative Appeal Process
11
Federal Register. Updating the Water Quality Certification Regulations
12
U.S. Environmental Protection Agency. Definition of Waters of the United States – Rule Status and Litigation Update
13
U.S. Environmental Protection Agency. Updated Definition of Waters of the United States Proposed Rule Fact Sheet for the Agricultural Community