401 vs 404 Permit: How the Two Clean Water Act Approvals Work Together

Updated November 2026

Section 401 and Section 404 are two different but related Clean Water Act approvals. A Section 404 permit from the U.S. Army Corps of Engineers authorizes placing dredged or fill material in waters of the United States, including wetlands. A Section 401 water quality certification comes from the state (or an authorized tribe) and says whether the discharge from that federal permit will meet state water quality requirements. On most Gulf Coast sites with wetland or water impacts, you need both, and they move best when filed together.

401 vs 404 at a glance

	Section 404 permit	Section 401 water quality certification
Who issues it	U.S. Army Corps of Engineers district, using EPA’s 404(b)(1) Guidelines	The state water quality agency (or authorized tribe): MDEQ, ADEM, FDEP or LDEQ on our side of the Gulf
What it covers	Discharge of dredged or fill material into waters of the U.S., including wetlands	Whether a discharge from a federally permitted activity complies with state water quality requirements
What triggers it	Fill or dredge placement in jurisdictional wetlands or waters (pads, road crossings, bulkhead backfill, revetments)	Any federal license or permit that may result in a discharge into waters of the U.S., most often a 404 and sometimes a Section 10 permit
Timeline	Nationwide Permits can move quickly; individual permits take a full public-notice review. Timing depends on the site and the district.	The state must act within a “reasonable period” set by the federal agency, never more than one year; under the 2023 rule the default is 60 days if no other period is set
How they relate	The Corps cannot issue the 404 until the 401 is granted or waived. 401 conditions become conditions of the 404.	Certify, certify with conditions, deny, or waive. A denial stops the federal permit.

For the wider permit map, see types of environmental permits and the Army Corps of Engineers permitting process.

Section 404: the dredge-and-fill permit

A 404 permit is the Corps decision on whether you may discharge dredged or fill material into wetlands or waters of the U.S. Fill for a building pad, a road crossing, a shoreline revetment, bulkhead backfill, or bridge abutments all sit in this lane when the features they are placed within are jurisdictional.

Nationwide Permit (NWP) vs individual permit, in plain English: NWPs are pre-written authorizations for categories of work that stay inside fixed impact and activity limits. If your footprint, resource hits, and purpose fit an NWP (and any regional conditions), you stay on that track. Most NWPs have expedited timelines for review and approval. Some of them have no review – you simply comply with the conditions and do the work. Many Nationwide Permits need a pre-construction notification to the district, and Nationwide Permits come with their own 401 decision from the state, issued when the NWPs are reissued, so check whether your state certified, conditioned or denied the NWP you plan to use.

An individual permit is the full project-specific review — public interest factors, alternatives, and usually a longer coordination path — used when impacts fall outside NWP boxes or the activity type does not qualify. Neither path is “easy” or “hard” by brand; they are different scopes of review.

Delineation and JD first. Before anyone argues NWP vs individual, know what is wetland or water and what the Corps claims. A field wetland delineation maps the features. A jurisdictional determination (JD) is the Corps call on which of those features are waters of the United States. Skipping that step is how owners place fill that was never authorized — or leave money on the table avoiding features that are not jurisdictional.

Section 401: state water quality certification

Section 401 is the state’s say on water quality for a federal permit. The certifying agency can certify, certify with conditions, waive, or deny. Denial (or failure to obtain certification in time) can block the Corps from issuing the 404 even when the federal review is otherwise favorable. Conditions on the 401 — turbidity controls, stormwater measures, outstanding-waters language — become conditions on the federal permit. The certifying agency in each Gulf state is listed in the state-by-state section below.

Tribal certification can apply where a tribe is the certifying authority. Coastal-zone consistency and state coastal permits are related but separate clocks — do not treat “we filed 401 or 404” as proof coastal review is done.

The 2023 401 certification rule (and what’s changing)

EPA’s Clean Water Act Section 401 Water Quality Certification Improvement Rule took effect November 27, 2023, and is the rule in force today. It sets what a certification request must include, lets the federal agency and state agree on a reasonable period for review (60 days by default, one year at most), and lets states look at water quality effects of the activity covered by the federal permit. EPA proposed changes to the 401 rule in January 2026. A final rule cleared White House (OMB) review in September 2026 but had not been published in the Federal Register as of November 5, 2026, so the 2023 rule remains in force. Certifications in process today follow the 2023 rule. If a revised rule is finalized, how it applies to pending requests will likely depend on how far along each request is.

401 and 404 by state: MS, AL, FL, LA

Mississippi. The 401 certification comes from the Mississippi Department of Environmental Quality (MDEQ). In Mississippi, the Corps district depends on where the water drains. Waters that drain to the Mississippi River or the Pearl River go to the Vicksburg District. Waters that drain to the Coastal Streams Basin, the Pascagoula River or Mobile Bay go to the Mobile District. Coastal-county work also goes through Mississippi’s coastal program review (Department of Marine Resources) on its own track.

Alabama. The 401 certification comes from the Alabama Department of Environmental Management (ADEM). The Corps’ Mobile District handles 404 permits in Alabama. Coastal-zone consistency in Baldwin and Mobile counties is a separate ADEM review.

Florida. The 401 certification is handled through FDEP’s Environmental Resource Permit (ERP) program: an ERP issued by FDEP or a water management district generally also serves as the state’s 401 certification. The Corps’ Jacksonville District handles all Corps regulatory work in Florida, including the Panhandle. About Florida’s state 404 program: EPA approved Florida to run its own 404 program in December 2020. A federal district court vacated that approval in February 2024, and the Corps took back 404 permitting in Florida. In March 2026 the D.C. Circuit largely upheld that ruling and in October 2026 declined to rehear it. Florida has not filed a Supreme Court petition as of November 5, 2026; the rehearing denial opened a new window that runs into early 2027. For now, plan Florida projects on the federal Corps 404 path plus a state ERP.

Louisiana. The 401 certification comes from the Louisiana Department of Environmental Quality (LDEQ). The Corps’ New Orleans District handles 404 permits for south Louisiana, including the Florida Parishes east of Baton Rouge. Work in the coastal zone also needs a Coastal Use Permit from the Louisiana Department of Conservation and Energy, Office of Coastal Management (formerly part of the Department of Energy and Natural Resources), which often runs as a joint application with the Corps.

How 401 and 404 sequence on a real project

Typical private-site rhythm:

1. Delineate and, where needed, request a JD so the impact story is honest.
2. File the Corps package (NWP verification or individual) and request 401 from the state in parallel — not after the Corps is “almost done.”
3. The Corps waits on 401 certification or waiver before issuing many federal authorizations, including 404.
4. Run coastal consistency / state coastal or ERP review on its own track when the footprint triggers it.

Short Gulf example (no client names). A waterfront lot near Biloxi needs a short approach fill and a pier tie-in. Delineation shows fringe marsh at the toe. The owner wants one “wetland permit.” Reality: Corps 404 (and often Section 10 for the structure in navigable water), MDEQ 401 on the federal action, and Mississippi coastal-program review in the coastal counties — three lanes, one construction season. Filing 404 alone and discovering 401 and coastal later is how pile schedules and closings collide. Cypress Environment & Infrastructure files the 404 package and coordinates the 401 so the state and federal clocks do not miss each other. If you are scoping a site now, contact us with a sketch and tax parcel — we will tell you which permitting lanes are required before you finalize plans.

Which one do you need?

Decision help for private owners and developers:

• Dredge or fill in wetlands or waters the Corps claims? You are in 404 territory (NWP or individual). Start with delineation/JD, then the Corps path.
• Federal 404 (or other federal license) in play? Expect a 401 request to the state unless a written waiver or a genuine exception applies. Budget state conditions as real construction constraints.
• Corps JD says not jurisdictional? You may leave 404 — you do not automatically leave state coastal, ERP, stormwater, or local rules. Ask the next question the same week.
• Only upland work with no discharge to waters? Neither 401 nor 404 may apply; still confirm floodplain, local grading, and coastal overlays.
• Still hearing “401 vs 404” as either/or? They’re different but related approvals for the same work. On most wetland fill jobs in our region, plan for both.

How Cypress helps

We run the sequence owners actually need: delineation → JD → 404 / 401, with coastal consistency folded in when the site requires it. That means field work and agency packages that match, not a delineation report that dies in a drawer while someone else invents fill quantities.

Cypress Environment & Infrastructure works private and public clients from Biloxi, Mobile, and Pensacola, across our Gulf / Southeast practice. We do not invent timelines or fee quotes on this page — those depend on footprint, resources, and the live agency forms. We do give candid path calls early: NWP vs individual, whether 401 is on the critical path, and what “no JD” still leaves standing.

Related: wetland delineation · jurisdictional determination · environmental permitting services

FAQ: 401 vs 404 permit

Is “404 vs 401” the same question as “401 vs 404”?

Yes. Section 404 is the Corps dredge-and-fill permit; Section 401 is the state’s water quality certification on that federal permit. The order of the numbers doesn’t change who does what.

Do I need both a 401 and a 404?

Usually. If you need a Corps 404, you also need a state 401 certification or waiver before the Corps can issue it. For Nationwide Permits, the state may have already certified the permit in advance, sometimes with conditions.

Can a state 401 decision stop a 404 permit?

Yes. If the state denies certification, the Corps can’t issue the 404. If the state grants it with conditions, those conditions become part of the 404.

How long does a 401 certification take?

The federal agency sets a reasonable period for the state to act, and it can’t exceed one year. Under the 2023 rule the default is 60 days unless the agencies agree to something else. If the state doesn’t act in time, certification is waived.

Who issues 404 permits in Florida?

The U.S. Army Corps of Engineers, Jacksonville District. Florida’s state-run 404 program was vacated in 2024 and remains off while appeals continue.

Should wetland delineation come first?

Almost always. A delineation, and a jurisdictional determination when you need the Corps’ call, defines the impact; without it, choosing between a Nationwide and an individual permit and scoping the 401 is guesswork. See wetland delineation and what is a jurisdictional determination.