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Mitigation Options

Various options are available for mitigation, in addition to the traditional on-site concurrent option, depending on what can work best for the applicant and for the environment. Each option must conform with the appropriate local, state, and federal regulatory requirements and permit processes.

  • Wetland Banking - A mitigation bank is a wetland, stream, or other aquatic resource area that has been restored, established, enhanced, or (in certain circumstances) preserved for the purpose of providing compensation for unavoidable impacts to aquatic resources permitted under Section 404 or a similar state or local wetland regulation. A mitigation bank may be created when a government agency, corporation, nonprofit organization, or other entity undertakes these activities under a formal agreement with a regulatory agency.
  • In-Lieu Fee (ILF) Mitigation- In this approach to mitigation, a permittee pays a fee to a third party in lieu of conducting project-specific mitigation or buying credits from a mitigation bank. ILF mitigation is used mainly to compensate for minor impacts to wetlands when better approaches to compensation are not available, practicable, or when the use of an ILF is in the best interest of the environment. Compensation for larger impacts is usually provided by project-specific mitigation or a mitigation bank.

    An ILF represents the expected costs to a third party of replacing the wetland functions lost or degraded as a result of the permittee’s project. ILFs are typically held in trust until they can be combined with other ILFs to finance a mitigation project. The entity operating the trust is typically a nonprofit organization such as a local land trust, private conservation group, or government agency with demonstrated competence in natural resource management.
  • Off-site mitigation - Compensatory mitigation that is not located at or near the project that is affecting wetlands. Off-site mitigation is generally only allowed when on-site mitigation is not practicable and environmentally preferable. See guidance on selecting a mitigation site using a watershed approach:

Also see examples of code language in critical areas ordinances related to off-site mitigation (PDF, 51KB).

  • Advance mitigation - A form of permittee-responsible compensatory mitigation constructed in advance of a permitted impact. Advance mitigation can be proposed by any applicant, but the advance compensatory mitigation credits generated by a mitigation effort in advance of impacts can only be used by that same applicant. The credit value of mitigation efforts at a site will generally increase over time because the temporal loss is eliminated or decreased if a mitigation effort is established and meeting performance standards prior to the use of the generated credits.

    The U.S. Army Corps of Engineers and the Washington State Departments of Fish and Wildlife, Ecology, and Transportation developed an Interagency Guide on Advance Permittee-Responsible Mitigation.  The Guide is intended to help applicants in developing advance mitigation proposals, and explain how advance mitigation sites may be used to mitigate for unavoidable impacts.