NWP 27Effective 2026-03-15

Aquatic Ecosystem Restoration, Enhancement, and Establishment Activities

Requirements at a Glance

  • No Pre-Construction Notification (PCN) required
  • Authorized under Section 10 and Section 404
  • Must result in a net increase in aquatic resource functions and services
  • Prohibits converting a stream or natural wetland to another use like a reservoir
  • Prohibits converting tidal wetlands to another aquatic resource type
  • Temporary fills must be removed and site restored to pre-construction elevations
  • Must comply with General Condition 18 regarding endangered species consultation
  • Must not cause more than minimal adverse effects on navigation

Purpose & Scope

Nationwide Permit 27 authorizes activities in waters of the United States associated with the restoration, enhancement, and establishment of various aquatic ecosystems. This includes work in tidal and non-tidal wetlands and riparian areas, non-tidal rivers and streams, and other open waters. The permit is intended to support projects that provide a net increase in aquatic resource functions and services . The scope of authorized activities is broad, covering tasks such as the removal of small dams, installation of structures to restore flow, wetland planting, and the creation of oyster habitat or artificial reefs. However, the permit specifically prohibits activities like the conversion of a stream or natural wetlands to another use, such as a reservoir, or the conversion of tidal wetlands to another aquatic resource type.

What Changed in 2026

The 2026 reissuance of NWP 27 did not include any substantive changes to the national terms or conditions of the permit compared to the 2021 version. The Corps reevaluated the permit and determined that the existing qualitative and quantitative limits remain appropriate to ensure that authorized restoration activities result in no more than minimal individual and cumulative adverse environmental effects . Administrative updates were made to the supporting decision document to incorporate updated environmental baseline information, including data from the 2022 National Lakes Assessment and the 2021 National Wetland Condition Assessment. These updates ensure that the cumulative impact analysis is based on the most current national-scale ecological data available.

Who Needs This Permit?

Environmental consultants, conservation organizations, and government agencies involved in ecological restoration use this permit. It is designed for professionals managing stream rehabilitation, wetland establishment, or the restoration of coastal habitats like oyster reefs.

Common Project Types

  • Removal of small authorized dams to restore stream flow
  • Restoration of former wetlands on agricultural lands
  • Installation of post-assisted log structures for stream rehabilitation
  • Creation of oyster habitat or artificial reefs in estuarine waters
  • Re-establishment of native vegetation in riparian corridors
  • Remining and reclamation of abandoned mine lands

Environmental Review

The Corps determined that the reissuance of NWP 27 results in 'no effect' on federally-listed endangered or threatened species or their critical habitat. This is because General Condition 18 requires project-specific ESA Section 7 consultation for any activity that 'might affect' these resources, and no activity is authorized until that consultation is complete . Compliance with Section 106 of the National Historic Preservation Act is managed through General Condition 20, which requires a pre-construction notification if an activity has the potential to affect historic properties. For Essential Fish Habitat (EFH), district engineers can apply regional or activity-specific conditions to ensure that restoration work results in no more than minimal adverse effects on those sensitive areas.

Frequently Asked Questions

Do I need to submit a PCN for all NWP 27 activities?

What is the acreage limit for restoration under NWP 27?

Can I use NWP 27 to build a new pond in a wetland?

Is compensatory mitigation required for these projects?

Can NWP 27 authorize the removal of a dam?

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