NWP 5: Scientific Measurement Devices

Devices, whose purpose is to measure and record scientific data, such as staff gages, tide and current gages, meteorological stations, water recording and biological observation devices, water quality testing and improvement devices, and similar structures. Small weirs and flumes constructed primarily to record water quantity and velocity are also authorized provided the discharge of dredged or fill material is limited to 25 cubic yards.

Acreage limit

The 2026 rule states no acreage limit for NWP 5. Eligibility turns on the activity description in the rule text and the general conditions that apply, not on a numeric cap.

Discharge for small weirs and flumes limited to 25 cubic yards.

Pre-construction notification: Not required

NWP 5 carries no notification clause in the 2026 rule. Activities authorised solely under this permit do not need to file a PCN under general condition 32.

Source

Federal Register citation: 91 FR 768
Effective date: March 15, 2026
Cited text: 91 FR 768 - Reissuance and Modification of Nationwide Permits (final rule, 8 Jan 2026) Read the rule

What this page does not tell you

District regional conditions. Any of the 38 USACE districts can narrow NWP 5, add a notification requirement beyond general condition 32, or revoke the permit entirely inside its boundaries. PermitBird holds no compiled regional conditions yet. Check the district.
State Clean Water Act Section 401 certification. Each of the 54 states and territories must certify, condition, waive or deny use of this permit before it authorises a discharge there. PermitBird holds no compiled certification yet. Check the state.