Statewide wetland mapping inventory project

Project summary and results

This project, funded in part by an EPA Wetland Program Development Grant, was designed to:

• Identify the status and trends of local, regional, and statewide mapping efforts in Washington.
• Understand user needs for wetland map data.
• Foster communication and collaboration between wetland managers and stakeholders by providing contacts for wetland map data.

We contacted local and Tribal governments, state and federal agencies, and land managers who regulate or manage wetlands to invite them to participate in our project. Voluntary participants completed a survey and engaged in discussions with us regarding the wetland map data they use and produce. 

Results showed most users rely on the wetland maps developed by the National Wetland Inventory (NWI). Wetland spatial data created by respondents are variable and often derived from the NWI data, with support of field-verified data if available.

These results highlight the need to update the NWI data for the entire state since most of Washington's NWI coverage was mapped before 1990. In addition, a wealth of new and historic wetland information is waiting to be digitized. Survey respondents indicated they would benefit from guidance on digitizing field-verified wetland data, which would help standardize wetland spatial data across the state and support future NWI updates.

See the NWI Projects Mapper to find out when the NWI wetland maps were generated as well as the current status of NWI updates in Washington.

Project deliverables and downloadable resources

Using survey results and discussions with participants, we generated a statewide list of existing and ongoing mapping projects and resources. This list, paired with the interactive map above, allows you to see the broad geographic regions where wetland mapping is occurring in Washington. 

• Contact and data spreadsheet. This Excel spreadsheet includes contact information for project participants, indicates if they actively create wetland spatial data, and provides information about the data that are available to be shared publicly.

This project also resulted in a summary report regarding wetland map data.

• Summary report. Summary of survey responses and synthesis of results, October 2022.

All data represented here were current during the time frame of this project and may be subject to change. Contact specific participants for the most up-to-date information about their data.