The U.S. Army Corps of Engineers (the Corps) has reissued and modified the Corps’ Nationwide Permits (NWPs), which authorize certain categories of work in Waters of the United States under Section 404 of the Clean Water Act (33 U.S.C. § 1344) and Section 10 of the Rivers and Harbors Act of 1899 (33 U.S.C. § 401 et seq.). Nationwide permits are intended for those projects that will result in no more than minimal adverse environmental effects.

NWP Changes

The final rule reissues 56 existing NWPs, adds one new NWP, declines to renew one NWP, and makes targeted modifications to certain conditions and requirements. The 2026 NWPs take effect March 15, 2026. The NWPs will impact how projects are planned and the speed with which they are able to get permitted and break ground.

NWP 60: A New Path for Fish Passage

The Corps has issued a new NWP—NWP 59 “Water Reclamation and Reuse Activities – Activities to Improve Passage of Fish and Other Aquatic Organisms.” This new NWP specifically authorizes structures and work in navigable waters and discharges of dredged or fill material for activities designed to, or that will incorporate “nature-based” solutions that restore or enhance the passage of fish and other aquatic organisms.

NWP 56: Finfish Mariculture Not Reissued

On the other hand, NWP 56, which previously covered finfish mariculture activities, is not being reissued. NWP 56 will expire on March 14, 2026.

NWP 39: Commercial and Institutional Developments Include Data Centers

In a move that acknowledges the growing footprint of data centers, NWP 39 “Commercial and Institutional Developments” authorizing discharges of dredged or fill material for the construction or expansion of commercial and institutional buildings now explicitly includes by way of example “data centers (to include, for example, artificial intelligence and machine learning facilities)”. This provides a clearer permitting pathway for this rapidly expanding sector.

NWP 13 and 43: Nature-Based Solutions

The Corps reissued NWPs 13 “Bank Stabilization” and 43 “Stormwater Management Facilities” to eliminate the term “green infrastructure” and replace it with “nature-based solutions.” NWP 13 “Bank Stabilization” now includes a paragraph clarifying that the NWP can be used to authorize regulated activities that incorporate nature-based solutions associated with bank stabilization activities, including those in conjunction with hard bank stabilization activities such as seawalls, bulkheads, and revetments. “Nature-based solutions” is defined as “[a]ctions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits.”

NWP 27: Streamlining Restoration

The Corps removed the PCN requirement for NWP 27 “Aquatic Ecosystem Restoration” unless required by the general conditions or regional conditions. The Corps also expanded the concept of acceptable ecological references to include not just existing intact systems but also cultural ecosystems, which may be based on regional ecological knowledge, including indigenous ecological knowledge. These changes should give project proponents greater latitude in defining acceptable restoration.

NWP 48: Commercial Shellfish Mariculture in Washington State

The final rule excludes the use of NWP 48 “Commercial Shellfish Mariculture Activities” within waters in Washington State. NWP 48 effectively had not been used for projects in Washington State since 2017, when the U.S. District Court for the Western District of Washington vacated the use of NWP 48 in Washington State waters. As has occurred since 2017, project proponents in Washington State must seek authorization for regulated activities or structures that would otherwise fall under NWP 48 under an individual permit or a letter of permission.

Updates to General Conditions

Compliance with NWPs requires that a project proponent adhere to the Corps’ NWP General Conditions (GCs),  several of which have been tweaked in the final rule:

• GC 9 (Management of Water Flows): Now explicitly includes “tidal flows” in the definition of expected high flows to clarify that expected high flows, and normal or high flows, include the flow of water caused by tides.
• GC 11 (Equipment): New language requires that areas affected by the use of mats must be restored to pre-construction elevations and revegetated.
• GC 25 (Water Quality): The general condition clarifies that the proposed activity, which may result in a discharge from a point source, would have to be into a Water of the United States in order to trigger a Clean Water Act Section 401 Certification. This change was to make the language consistent with the text of the Clean Water Act Section 401.

Project Planning for 2026

The reissued NWPs will go into effect on March 15, 2026, and are set to expire on March 15, 2031.

For projects utilizing an NWP, the transition period is critical. Activities that were authorized by the 2021 NWPs and have either commenced or are under contract to commence by March 14, 2026, will have one year to complete the work. These projects must be finished by March 14, 2027, to remain covered under the previous NWP authorization.

If an activity authorized by the previous NWPs has not started or is not under contract by March 14, 2026, or if it cannot be completed by the 2027 deadline, it will require reauthorization under the 2026 NWPs.

Developers and project applicants should review current project timelines against these dates to determine the impacts for projects that are under way or that are permitted. Projects that are considering beginning permitting in 2026 should evaluate how the NWP changes may affect permitting and project timing.

This article summarizes aspects of the law and opinions that are solely those of the authors. This article does not constitute legal advice. For legal advice regarding your situation, you should contact an attorney.