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Managing Mitigation Sites

Replanting photo
Replanting efforts at an active site

This page outlines the steps
WSDOT follows to manage wetland mitigation sites. 

Adaptive Management Process

Adaptive management is a critical component of WSDOT's monitoring and site management. The adaptive management process includes four steps relevant to site management after construction of wetland mitigation sites:

  • Performance criteria are developed to describe the desired condition.
  • Management action is carried out to meet the performance criteria.
  • Response of the resource is monitored to determine if the performance criteria have been met.
  • Management is adjusted if the performance criteria are not achieved.

Monitoring and responsive site management are both integral to the success of an effective adaptive management strategy. Without valid monitoring data, management actions may or may not result in improved conditions or compliance with regulatory permits. Timely site management decisions, based on valid monitoring data, result in increased efficiency and higher probabilities of success. Sometimes the performance criteria for a mitigation site must be re-evaluated by the site manager, environmental coordinator, and regulatory agencies. The adaptive site management process is illustrated below.

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The Adaptive Site Management Process (Redrawn from Elzinga et al. 1998)

Adjusting Site Management

Site managers rely on monitoring results to inform them of site performance. If the monitoring results show that a site is not on a trajectory to meet performance criteria or permit requirements, the site manager will decide whether new management activities should be employed.

Site managers use monitoring results and recommendations, best available science, and their professional judgment to decide which management activities are best to take at each mitigation site. Implementing management actions involves:

  1. Type of action
  2. Timing of action
  3. Documentation
  4. Evaluating effectiveness (follow-up site visits)

Designers and site managers may use contracts or state force to provide management activities on mitigation sites. 

Site Closeout

When a site has reached the end of its specified monitoring period and achieved reasonable ecological success, the site manager can request that it be “closed out.” If requested, the Monitoring Team can prepare a closeout rationale. At this point, the Regional Environmental Manager (or his/her designee) sends a cover letter and copy of the final monitoring report and/or closeout report to the regulatory agencies to inform them that this milestone has been reached. The cover letter explains the rationale for closing out the site, and extends an invitation to regulatory agency staff to visit the site for their concurrence. After concurrence has been received from the regulatory agencies, formal monitoring and reporting ceases.

Long-Term Site Maintenance

After a mitigation site has been closed out, stewardship responsibility of the site is transferred from region environmental staff to region maintenance staff. WSDOT is responsible for protecting the site in perpetuity unless other arrangements have been made, such as transferring the site to a local or federal agency, or conservation organization. Most sites are designed to be self-sustaining. However, periodic site management such as fence repairs or noxious weed control is considered on an as-needed basis.