Interagency wetland mitigation guidance

Wetland Mitigation in Washington State, Version 1, is a two-part interagency document providing guidance on wetland mitigation. You can access the current mitigation guidance document (Parts 1 and 2) below.

Cover page of proposed document.

Public comment period: Oct. 1, 2020 to Nov. 30, 2020

Ecology, the U.S. Environmental Protection Agency Region 10, and the U.S. Army Corps of Engineers, Seattle District, are soliciting comments from interested parties on a draft update to the 2006 interagency guidance, Wetland Mitigation in Washington State, Part 1.
For more information see our public comment webpage.

Current mitigation guidance documents

Part 1 — Agency policies and guidance

Part 1 provides a brief background on wetlands, an overview of the factors that are considered in the agencies' permitting decisions, and detailed guidance on the agencies' policies on wetland mitigation, particularly compensatory mitigation.

Part 2 — Developing mitigation plans

Part 2 provides technical information on preparing plans for compensatory mitigation.

Monitoring guidance

The U.S. Army Corps of Engineers (Corps) issued a regulatory guidance letter to clarify monitoring requirements for compensatory mitigation projects. The Corps' Seattle District has incorporated the most recent guidance letter (RGL 08-03) into their monitoring requirements for compensatory mitigation projects.

Other mitigation resources

We have published a number of guidance documents designed to improve mitigation. For example, in 2009 and 2010, we published guidance on selecting wetland mitigation sites using a watershed approach for both Eastern and Western Washington. This and all other mitigation guidance is available on our Wetland Mitigation Resources page.

We announce when new guidance is available through our wetlands information email Listserv.