The U.S. Army Corps of Engineers, Northwestern Division, administers a comprehensive Regulatory Program, rooted in one of the federal government’s earliest laws to protect the navigable capacity of the nation’s waters. The Regulatory Program has evolved significantly since inception, gaining scope, complexity, and authority in response to shifting public needs, court rulings, and legislation. Spanning 11 states in the Pacific Northwest, North Central and Central U.S., the Northwestern Division operates through its five districts: Kansas City, Omaha, Portland, Seattle, and Walla Walla.

The division implements Section 10 of the Rivers and Harbors Act of 1899, Section 404 of the Clean Water Act, and Section 103 of the Marine Protection, Research, and Sanctuaries Act, requiring permits for activities in navigable waters, for the discharge of dredged or fill material into waters of the U.S., including wetlands, and for the transport and disposal of dredged material in the ocean. The Northwestern Division is the largest division, issuing thousands of permits annually, while balancing the protection of the nation’s aquatic ecosystems with responsible development, providing fair, balanced, and timely decisions while maintaining the chemical, physical, and biological integrity of waters of the United States.

Mitigation Information

The overall objective of the Clean Water Act (CWA) is "to restore and maintain the chemical, physical, and biological integrity of the Nation's waters." To achieve this goal, the CWA prohibits the discharge of dredged or fill material into wetlands, streams, and other waters of the United States unless a permit is issued by the U.S. Army Corps of Engineers. During the permit review process, the applicant must demonstrate that he or she has avoided and minimized impacts to aquatic resources to the maximum extent practicable. For any remaining unavoidable impacts, compensatory mitigation is usually required to replace the loss of wetland, stream, and/or other aquatic resource functions. The Corps is responsible for determining the appropriate form and amount of compensatory mitigation that may be required. Methods of providing compensatory mitigation include aquatic resource restoration, establishment, enhancement, and in certain circumstances, preservation.

In accordance with the Final Compensatory Mitigation Rule, the applicant is required to provide a "Mitigation Statement" with any application stating how he or she intends to compensate for the loss of aquatic functions or why compensatory mitigation should not be required. As the development and implementation of a compensatory mitigation project can be beyond the capability of many applicants, the Final Compensatory Mitigation Rule expresses a preference for first, obtaining mitigation credits from an established mitigation bank; second, purchasing credits from an approved in In-Lieu-Fee program; and lastly, by providing permittee responsible mitigation.

Final Compensatory Mitigation Rule

Regulatory in Lieu Fee and Bank Information Tracking System (RIBITS)

STREAM FUNCTION ASSESSMENT METHOD FOR IDAHO (SFAM)

The U.S. Army Corps of Engineers, Walla Walla District released the Stream Function Assessment Method for Idaho (SFAM), beta version 1.0. The SFAM is a standardized, rapid, stream functional assessment methodology for use in Idaho and is a regionalized adaptation of the method developed for Oregon (Nadeau et al., 2020). The Idaho version of SFAM closely follows the method developed for Oregon, with modifications made to reflect Idaho-specific data sources and recently available data and research.

Click here to view the Special Public Notice regarding the SFAM and to access the Idaho SFAM Workbook

Click the links below to access the SFAM documents:
Idaho SFAM User Manual
Idaho SFAM Scientific Rationale

Click the link below to download the Idaho SFAM Workbook:
Idaho SFAM Workbook

Idaho Wetland Ecosystem Services Protocol (WESP-ID)

The Wetland Ecosystem Services Protocol for Idaho (WESP-ID) is functional assessment methodology for use in Idaho. WESP-ID is a standardized method for rapidly assessing wetland functions, which can then be used to help inform project site selection alternatives, as well as the selection, design, credit determination and monitoring of compensatory wetland mitigation sites.

Click here to view the Special Public Notice regarding the WESP-ID

Click here to access the WESP-ID Manual

To obtain a copy of the accompanying Excel® spreadsheet calculator, please contact the Regulatory Division at CENWW-RD-IDWESP-PN@usace.army.mil or 208-433-4464.