Wetland Mitigation Monitoring

Washington State Requirements


In Washington, the U.S. Army Corps of Engineer's Seattle District refers to Regulatory Guidance Letter (RGL) 08-03 for guidance on minimum monitoring requirements for mitigation projects, including the required minimum content for monitoring reports.  The Corps requires submission of monitoring reports to assess the development and condition of wetland mitigation projects. The content and level of detail depends on the scale, scope, and type of mitigation.

RGL 08-03 specifies that the monitoring report narrative should be concise and generally less than 10 pages.  This length requirement helps to ensure that only pertinent information is submitted.  This helps expedite agencies' review and determination of whether the mitigation project is in compliance.

For specific projects, the Corps' Seattle District determines how frequently monitoring reports are submitted, the monitoring period length, and report content.  Permit conditions will support the specified monitoring requirement and include deadlines for monitoring report submittal. The Corps will also accept monitoring reports that follow Ecology guidelines, provided permittees also include panoramic photographs of the mitigation site with the monitoring report.


RGL 08-03 is consistent with Washington's interagency wetland mitigation guidance (March 2006). In most cases, monitoring reports are required as a condition of Ecology's Order.

Monitoring report contents

For specific projects, Ecology typically lists the required monitoring information in an attachment (Information Required for Monitoring Reports) to the Order. For Orders that do not have this attachment, refer to either RGL 08-03 or Information Required for Monitoring Reports

Submittal requirements

In order to determine the specific submittal requirements for your project, refer to the relevant conditions in Ecology’s Order. For more recent projects, the condition will say something like: “The Applicant shall submit to Ecology one hard and one electronic copy of monitoring reports documenting mitigation site conditions for years 1, 2, 3, 5, 7, and 10 . . .”

Ecology needs at least one paper copy of each monitoring report; however, the agencies also encourage electronic submittals of reports.  This allows for easy distribution to the appropriate agency staff and will limit the number of paper copies needed. There should be an address listed in Ecology's Order for whom to submit it to (usually the Federal Permit Manager in the region where the Order was issued). The electronic copy can be sent via email if it is 30 MB or less. If it is larger than 30MB, you can send a copy on a CD.

Failure to submit completed monitoring reports in a timely manner could result in an extension of the monitoring period or additional mitigation requirements.

General Information on Monitoring

When mitigation is required to compensate for unavoidable impacts to wetlands and other aquatic resources, a monitoring plan should be included in the mitigation plan.  The goals, objectives, and performance standards for a mitigation project are the basis for the monitoring plan and are the measure against which compliance and success are determined.  The duration, frequency, and methods of monitoring depend on a project's goals, objectives, and performance standards.

In general, monitoring is required for ten years.  The monitoring period may be extended if performance standards are not being met.

Monitoring helps to ensure that a mitigation project achieves its stated purpose and complies with permit obligations.   It also provides critical information about whether a site needs maintenance or whether the applicant needs to take corrective actions. 

The information collected through monitoring should address the established goals, objectives, and performance standards. This information will be used to determine whether the project is achieving ecological success within the expected timeframe. Regular monitoring reports also provide an opportunity for agency staff to help identify the extent of any problems and any necessary remedial measures.

Monitoring data is important for the permit applicant as well as the agencies because it can reveal conditions that are unfavorable for attaining final performance standards. By implementing contingency plans (e.g., replanting dead or dying vegetation or re-grading parts of the wetland) based on this information, applicants can take corrective steps to help ensure that the site is a success at the end of the monitoring period.

Finally, monitoring reports need to be as objective as possible. They can be used by the agencies, as a part of the official case file, to analyze and record permit compliance and the overall success of mitigation as compensation for wetland loss and degradation. Monitoring can also serve to increase our knowledge of the effects of specific actions.


If you have any questions on monitoring or report requirements you can contact wetland mitigation compliance staff at Ecology:

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