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King County has the first "in-lieu fee" mitigation program in Washington state to be certified under 2008 federal rules.

The revised Mitigation Reserves Program may offer some permit applicants an option to purchase mitigation credits from King County to fully satisfy mitigation obligations associated with projects that result in unavoidable impacts to wetlands, rivers, streams, or buffers. The county then uses collected mitigation fees to implement mitigation projects that make up for impacts to aquatic resources.

On this page:

An overview of in-lieu fee mitigation

When permitted projects will create unavoidable impacts to the environment, project sponsors must offset, or "mitigate" the environmental impacts associated with the project. The mitigation process includes avoiding and minimizing impacts as much as possible, and then making up for any unavoidable impacts through implementation of a mitigation project. Mitigation projects can occur on-site (at or near the place where the impact project occurs) or off-site. King County Code prioritizes on-site mitigation when it is ecologically feasible and likely to succeed long-term. However, if mitigation on or adjacent to the development site is impractical or won’t result in meaningful ecological benefit, off-site mitigation becomes an option under King County code and state and federal rules. Off-site mitigation options may include use of a mitigation bank, "permittee-responsible" mitigation, or in-lieu fee mitigation through the Mitigation Reserves Program.

In a Federal Rule (PDF file 567 KB) published in April 2008, The U.S. Army Corps of Engineers (the Corps) and the U.S. Environmental Protection Agency (EPA) define an in-lieu fee program as:

    “A program involving the restoration, establishment, enhancement, and/or preservation of aquatic resources through funds paid to a governmental or non-profit natural resources management entity to satisfy compensatory mitigation requirements... Similar to a mitigation bank, an in-lieu fee program sells compensatory mitigation credits to permittees whose obligation to provide compensatory mitigation is then transferred to the in-lieu program sponsor.”

Basics of the Mitigation Reserves Program

Here is a step-by-step example of the process for mitigating unavoidable permitted impacts to wetlands, rivers, streams, and buffers through the MRP*:

  1. Applicants work with regulatory agencies and tribes to identify ways a proposed project can avoid and minimize environmental impacts.
  2. Regulatory agencies determine preferred options for mitigating unavoidable impacts. Mitigation options may include:
    Mitigation project at Cold Cr Natural Area
    • on-site mitigation (if ecologically-feasible and likely to succeed),
    • off-site mitigation sponsored by the permittee,
    • purchasing credits from a mitigation bank (if one is available), or
    • purchasing credits from the Mitigation Reserves Program.
  3. If the applicant chooses to use the KC MRP (and the regulatory agencies approve), the ecological impacts translated into a number of debits associated with the impact.
  4. The applicant buys credits from the KC MRP to offset the debits associated with the impact. By purchasing credits, the applicant satisfies their compensatory mitigation requirements and have no further involvement in the mitigation implementation.
  5. The KC MRP chooses a mitigation site from a predefined Roster. Roster sites may be publicly or privately owned, and will be chosen based on science-based watershed priorities (see Exhibits 2-9 for maps of Roster sites).
  6. The KC MRP plans, implements, monitors and maintains projects at chosen sites that will achieve ecological “lift.” On balance, completed projects should result in a number of credits equal to or greater than the number of debits associated with the original impacts.

*At multiple points in the process, an Interagency Review Team will review and approve project proposals. The IRT is co-chaired by the Corps and the Washington Department of Ecology (Ecology); other members will include representatives state and federal regulatory agencies, tribes, and local governments.

Service Areas

The program is available in seven "Service Areas" in King County. Impact occurring in a service area must be mitigated within the same service area.

King County Mitigation Service Areas


Using MRP in cities

The program is designed to satisfy mitigation obligations for a wide variety of permit types, including federal, state, and local permits. As of February 2012, the program is available throughout unincorporated King County. The program may be available to project proponents working within incorporated cities if the city codes allow it.  Please contact Megan Webb for more information.

MRP Program Instrument

The Program Instrument is a set of documents describing operations of the program and the framework for implementing mitigation. It is also a legal contract among King County and the Corps and Ecology--the parties to the instrument. After the program is "certified" it will be compliant with federal, state and local rules and regulations and will chart the way for King County to continue successfully meeting mitigation needs for unavoidable permitted impacts.

The links below lead to the set of documents constituting the Program Instrument:

Note: The final, signed version will be posted to this website after the instrument is signed. The documents above are nearly identical to the final versions (there were minor edits for clarity and to fix typos).

Certification process

The Mitigation Reserves Program was certified for operation on March 12, 2012

  • In June 2009, King County submitted to the Corps, Ecology, and EPA a program Prospectus which outlined the basic concept of the program. The Prospectus made available for public review.
  • In December 2009, King County incorporated public comments and feedback from the IRT on the program prospectus into a draft Program Instrument which was submitted to the IRT for review.
  • In March 2010 King County staff and members of the IRT met to discuss the draft instrument.
  • Negotiations about program details continued through 2010, during which time the Program Instrument was significantly revised.
  • In June 2011, King County submitted to the IRT a Final Program Instrument.
  • In July 2011, the Corps and Ecology, with consent from all IRT members, issued letters stating their intent to certify the program.
  • In mid September 2011, King County staff completed a State Environmental Policy Act (SEPA) environmental checklist. On September 22, 2011 King County issued a Determination of Non-Significance (DNS) related to environmental impacts of certifying the program, after which there was a two-week public comment period. No comments were submitted.
  • In late October 2011 King County Executive Constantine transmitted an ordinance to King County Council by which the Council will authorize the executive to sign the Instrument.
  • In January 2012, the King County Council unanimously passed the authorizing ordinance
  • On March 12, 2012, Colonel Bruce Estok signed the program instrument, officially certifying the program.

For more information about King County’s Mitigation Reserves Program, please contact Megan Webb, WLR Rural and Regional Services Section.