NWP 5Effective 2026-03-15

Scientific Measurement Devices

Requirements at a Glance

  • No Pre-Construction Notification (PCN) required
  • Authorized under Section 10 and Section 404
  • Discharge of dredged or fill material for weirs and flumes is limited to 25 cubic yards
  • Devices and associated structures must be removed once data collection is complete
  • Sites must be restored to pre-construction elevations after device removal
  • Activities must comply with General Condition 2 regarding aquatic life movement
  • Does not authorize the construction of artificial reefs

Purpose & Scope

Nationwide Permit 5 authorizes the installation of devices used to measure and record scientific data. Authorized structures include staff gages, tide and current gages, meteorological stations, water recording devices, and biological observation tools. It also covers devices for water quality testing and improvement, provided they are used for data collection purposes. The permit allows for the construction of small weirs and flumes primarily intended to record water quantity and velocity. However, these specific structures are subject to a strict volume limit: the discharge of dredged or fill material cannot exceed 25 cubic yards. All devices and associated structures, such as foundations and anchors, must be removed and the site restored to its original elevation once the data collection period ends.

What Changed in 2026

The 2026 reissuance of NWP 5 includes no substantive changes to its terms or conditions compared to the 2021 version. The Corps of Engineers reevaluated the permit's individual and cumulative effects and determined that the existing qualitative and quantitative limits remain sufficient to ensure only minimal adverse environmental impacts. While the permit text remains unchanged, the supporting decision document has been updated with current environmental baseline data. This includes information from newer national-scale assessments, such as the 2022 National Lakes Assessment and the 2021 National Wetland Condition Assessment, ensuring that the environmental review reflects the most recent scientific data available.

Who Needs This Permit?

This permit is typically used by scientific researchers, environmental consultants, and government agencies involved in hydrology, meteorology, or aquatic biology. It facilitates the quick deployment of monitoring equipment for data-driven environmental management and public safety projects.

Common Project Types

  • Installation of stream staff gages and tide monitors
  • Deployment of floating water quality sensors with anchors
  • Construction of small 25-cubic-yard flumes for flow measurement
  • Placement of meteorological stations in wetlands
  • Installation of biological observation devices for fish tracking
  • Deployment of water recording stations for drought monitoring

Environmental Review

The Corps determined that reissuing NWP 5 has 'no effect' on federally-listed endangered or threatened species or their critical habitat. This finding is supported by General Condition 18, which requires project-specific ESA Section 7 consultation if an activity 'might affect' listed species; no such activity is authorized until the consultation process is successfully completed . Compliance with the National Historic Preservation Act is similarly managed through General Condition 20, which triggers a mandatory Pre-Construction Notification (PCN) if an activity has the potential to affect historic properties. The Corps also found that the activities result in only minor changes to the current environmental setting across the United States and its territories.

Frequently Asked Questions

Do I need to submit a PCN for installing a staff gage under NWP 5?

What is the discharge limit for weirs and flumes under this permit?

Can I leave my scientific measurement device in the water permanently?

Can NWP 5 be used for water quality improvement projects?

Does NWP 5 authorize the construction of artificial reefs for biological study?

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