Advance permittee-responsible mitigation

To compensate for unavoidable impacts to wetlands, advance mitigation is an available compensation option. Advance mitigation is a form of mitigation or compensation implemented by a permittee before a permitted wetland impact occurs. This is often referred to as "permittee-responsible compensatory mitigation." It is designed to compensate for future expected impacts. An advance mitigation site generates value — or credits — over time until the site reaches its maximum potential by meeting all of its required performance standards.

Benefits of advance mitigation

  • Reduced temporal loss. Successful compensation completed before impacts occur will reduce or eliminate the temporal loss of wetland functions associated with the impact — and is environmentally preferable.
  • Decreased risk of failure. The risk of failure decreases as the permittee demonstrates that the compensation site is achieving its goals, objectives, and performance standards.
  • More cost effective. Ratios required to offset impacts generally will be reduced due to the decreased temporal loss and risk of failure, making advance mitigation more cost effective.

Who can develop and use advance mitigation

An advance mitigation site can be proposed by any public or private entity. The permittee of the advance mitigation is responsible for site development, management, performance, and protection. 

The credits from the advance mitigation can only be used by the permittee that developed the advance site and cannot be sold or transferred to another entity. If a permittee wants the ability to sell or transfer credits to another entity, the compensation project must go through the wetland mitigation banking certification process.

Applicants conduct advance mitigation at their own risk. Establishing compensation in advance of impacts does not guarantee that the advance mitigation will be considered adequate and/or suitable for any specific future impacts.


When applying for approval to establish an advance mitigation site, applicants are required to provide an Advance Mitigation Plan. The plan contains information similar to that required for approval of a concurrent mitigation plan (see Wetland Mitigation in Washington State - Part 2: Developing Mitigation Plans).

Baseline conditions must be verified before proceeding with an advance mitigation project
For advance mitigation, agency verification of baseline conditions is necessary to qualify for reduced ratios associated with advance mitigation, therefore pre-approval of a mitigation plan prior to commencing the mitigation effort is required. 

Advance mitigation plan contents
The advance mitigation plan must include the following information, consistent with the 2008 Federal Mitigation Rule and the 2012 Interagency Regulatory Guide: Advance Permittee-Responsible Mitigation:
  • Executive summary —​ Brief description of the history and intent of the project and the responsible parties involved (applicant/permitee).
  • Goals and objectives — Description of the resource type(s) and amount(s) that will be provided, the method of compensation (i.e., restoration, establishment, enhancement, and/or preservation), and the manner in which the resource functions of the compensatory mitigation project will address the needs of the watershed, eco-region, physiographic province, or other geographic area of interest.
  • Geographic service area — Proposed area in which potential future impacts may occur. Applicants do not need to identify specific impacts when submitting a proposed advance mitigation plan.
  • Site selection — Description of the factors considered during the site selection process. This should include consideration of watershed needs, how the proposed site will compensate for impacts within the proposed geographic service area, and the practicability of accomplishing an ecologically self-sustaining compensatory mitigation site.
  • Baseline conditions — Description of the ecological characteristics of the proposed compensatory mitigation project site. This should include descriptions of historic and existing hydrology, historic and existing plant communities, soil conditions, a map showing the location of the mitigation site(s) and the geographic coordinates for the site(s), and other site characteristics appropriate to the type of resource proposed as compensation. The baseline information should also include a delineation of wetlands and other aquatic resources on the proposed compensatory mitigation project site.
  • Mitigation Work Plan — Detailed written specifications and work descriptions for the compensatory mitigation project — including but not limited to — the geographic boundaries of the project; construction methods, timing, and sequence; source(s) of water, including connections to existing waters and uplands; methods for establishing the desired plant community; plans to control invasive plant species; the proposed grading plan, including elevations and slopes of the substrate; soil management; and erosion control measures.
  • Determination of credits — Description of the number of credits (i.e., value of the compensation) to be provided, including a brief explanation of the rationale for this determination. This should include an explanation of how the compensatory mitigation project will provide compensation for potential, future, unavoidable impacts to aquatic resources.
  • Performance standards — Ecologically-based standards that will be used to determine whether the compensatory mitigation project is achieving its objectives.
  • Monitoring —​ Description of parameters to be monitored in order to determine if the compensatory mitigation project is on track to meet performance standards and if adaptive management is needed. A schedule for monitoring and reporting on monitoring results must be included.
  • Maintenance —​ Description and schedule of maintenance requirements to ensure the continued viability of the resource once initial construction is completed.
  • Use of credits — ​Description of how advance mitigation credits may be used to off-set future, potential, unavoidable wetland impacts. This should include a proposed ratio reduction table and a discussion that future, proposed, unavoidable wetland impacts will need to be described in an advance mitigation use plan. A proposed credit ledger must be included.
  • Contingency/adaptive management monitoring — Management strategy to address unforeseen changes in site conditions or other components of the compensatory mitigation project, including the party or parties responsible for implementing adaptive management measures. The adaptive management plan will guide decisions for revising compensatory mitigation plans and implementing measures to address both foreseeable and unforeseen circumstances that adversely affect compensatory mitigation success.
  • Site protection — Description of the legal arrangements and instrument, including site ownership, that will be used to ensure the long-term protection of the compensatory mitigation project site. This section should also include a discussion of the width and condition of the perimeter buffer needed to protect the compensatory mitigation site.
  • Long-term management and maintenance —​ Description of how the compensatory mitigation project will be managed after performance standards have been achieved to ensure the long-term sustainability of the resource, including long-term financing mechanisms and the party responsible for long-term management.
  • Financial assurances —​ Description of financial assurances that will be provided and how they are sufficient to ensure a high level of confidence that the compensatory mitigation project will be successfully completed, in accordance with its performance standards.

When proposing advance mitigation, applicants need to determine the value of the compensation site as it matures over time. This can be done in a variety of ways:

  • Option 1 - For compensation sites that will involve only one method of compensatory mitigation – such as creation – the area of wetland created may be the simplest measure of value. Though the area will not change over time, the value would increase by reducing the compensation ratios applied to the proposed wetland impacts. For example, an applicant proposes to create five acres of Category III wetland. As the site meets year-specific performance standards, reduced compensation ratios would be applied to the applicant’s proposed wetland impact.
  • Option 2 - Credits can be assigned based on the anticipated functional lift from various methods of compensation. Crediting ratios can be applied to the site for each type of compensation activity (creation, rehabilitation, etc.) to generate a total credit value for the site. When using credits, a compensation ratio – which would reduce over time as the site matures – would be applied to potential impacts to determine how many credits would be used to compensate for a specific impact. 
  • Option 3 - You can use the Credit/Debit Tool which adjusts credit value based on the reduction of risk over time and the reduction in temporal loss as the site matures prior to impacts.

If you are considering advance mitigation, contact us to discuss which of these credit determination options is  appropriate for your specific proposal.

When an applicant proposes to use credit from their advance mitigation site to compensate for impacts associated with a specific project, the applicant must provide an advance mitigation use plan. It should include rationale to the agencies how the advance mitigation site will provide adequate compensation. For a detailed list of what should be included in an advance mitigation use plan, see the Interagency Regulatory Guide.

Based on the documentation provided by the applicant, the regulatory agencies with jurisdiction over the proposed impact will determine the following:

  • If the advance mitigation site provides the appropriate type and extent of mitigation necessary to compensate for the proposed impact.
  • If the advance mitigation site has area or credits available. An advance mitigation site needs to be functioning and meeting its required performance standards for at least two years after the completion of all grading and planting to attain advance mitigation value. If a permit applicant wishes to use mitigation credits during the first two years of the site, it will usually be reviewed as concurrent mitigation.

Advance mitigation can be combined with concurrent mitigation required by a federal, state, or local permit. This would apply if the concurrent mitigation site is planned to provide additional wetland area, additional functions, or some combination of additional area and function above and beyond what is required for the permitted impact. The additional compensation generated at a site would be established in advance of, and would generate credits for use against, expected future impacts. In these cases, the area being set aside for advance mitigation must be clearly identified and documented in the approved mitigation plan to distinguish it from the area being used as concurrent mitigation.

Ledger Templates

Ledger templates are provided in an Excel workbook and each workbook includes a template sheet and an instruction sheet. For advance mitigation projects there are three options:

  • Option 1 - When only one method of compensatory mitigation is used.
  • Option 2 - When more than one method of compensatory mitigation is used. 
  • Option 3 - When the credit/debit method is used to determine the value of the site.

For more detailed descriptions of these options see the "Crediting" tab.