Wetland monitoring

State and federal regulatory agencies typically require mitigation site monitoring for 10 or more years. Monitoring ensures the site effectively meets permit requirements.

Washington State Department of Transportation (WSDOT) regions and mode construct and manage mitigation sites. The WSDOT Headquarters (HQ) Monitoring Team evaluates each site annually and compares the site’s performance to criteria established in the Wetland and Stream Mitigation Report and environmental permits.

Wetland monitoring staff collect quantitative data to evaluate mitigation sites according to the WSDOT Wetland Program Monitoring Methods (pdf 98 kb). This document describes methods to collect data on factors specific to each site's performance criteria.

Find information on how to coordinate mitigation site monitoring with the Monitoring Team below, as well as information on long-term responsibilities after monitoring ends.

The most recent two years of monitoring reports are available on our Wetland monitoring reports webpage.

Initiating mitigation site monitoring

Region or mode mitigation staff should contact the HQ Monitoring Team throughout the mitigation site lifecycle, including:

  1. Before construction – Contact the HQ Monitoring Manager before construction because some mitigation sites require pre-construction monitoring.
  2. As construction of mitigation sites is completed – Notify the Wetland Program by submitting the monitoring start-up form (docx 39 kb) by January of the first year monitoring is required. Also, provide the following information to the Monitoring Team within the requested timeline. A delay in this information may prevent the team from monitoring hydrology in the early growing season (typically March) or collecting other baseline data.​
    • Final Mitigation Report (and any revisions) 
    • As-Built Plans 
    • Permits (and addenda) 
    • Right-of-Way Plan 
    • Fence or gate access 
    • Critical safety information 
    • Spatial information for original design polygons (delineation of existing on-site wetlands)
    • Site Protection Plan for cultural resources
    • Any information related to new project impacts being mitigated at existing advance mitigation sites
    • Notify the Wetland Program by submitting the monitoring start-up form (docx 39 kb) by January of the first year monitoring is required.
  3. Before any monitoring activities (usually in February to April) – Coordinate with the Monitoring Team to schedule a site visit to discuss:
    • Site boundaries
    • Zone boundaries
    • Performance standards
    • Problems encountered during construction
    • Safe site access
    • On-site safety 

Site coordination during monitoring period

Region or mode site managers continue to coordinate with the HQ wetland monitoring team throughout the monitoring period by

  • Reviewing the monitoring manager’s proposed fieldwork schedule to coordinate management and monitoring activities. For example, weed-spraying activities should not be conducted just before the Monitoring Team visit.
  • Sending documentation of management activities to the monitoring team for inclusion in the annual monitoring report.
  • Responding to feedback from the Monitoring Team regarding emerging problems at the site. For example, if the Monitoring Team sees invasive weed species, then they will notify the site manager so that weed control can take place.
  • Reviewing draft monitoring reports before they are submitted to the permitting agencies.

Concluding mitigation site monitoring

At the end of the monitoring period, the Monitoring Team closes out the site monitoring process by

  1. Documenting that WSDOT has provided the required wetland area and has met the performance standards.
  2. Requesting concurrence from regulators that we have met our permit obligations. 

While waiting for release from further monitoring or a notification that the permit conditions have been met, the Monitoring Team will continue to qualitatively monitor the site.

WSDOT’s long-term responsibilities for mitigation sites

WSDOT owns most of its mitigation sites and they will remain in state ownership in perpetuity. Other sites are owned by entities that have agreed to keep the area as a mitigation site after monitoring is complete.

WSDOT may transfer department-owned wetlands to qualified entities that agree to restrict the use of the property consistent with preservation of the wetland after permit obligations have been met (RCW 47.12.370). Regions should evaluate this option to reduce agency risk.

For WSDOT-owned sites, the long-term stewardship obligation either transfers to the Maintenance Division or WSDOT Environmental restoration crews.