Thurston County planning staff announced at the commission's meeting that the county's tree canopy assessment has been completed and published on the county website, on the Healthy Forest Project page. A planning staff member said the assessment uses LiDAR data to calculate vegetation height and canopy cover and that the report is intended as a regional visualization tool rather than a site-by-site permit-level analysis.

The staff member explained the maps are displayed using 250-acre hexagons so percentage comparisons are standardized across the county. "It's calculated directly from LiDAR data," the staff member said, adding the visualization uses hexagons to avoid misleading results that can arise when comparing very small and very large parcels. The presenter said the LiDAR analysis identifies existing canopy, conversion risk and restoration opportunities and is already informing the county's comprehensive plan update and research on riparian habitat protection.

Commissioners raised technical questions about the dataset's limitations. Commissioner Kevin Pestinger (District 5) asked whether a high figure cited in prior briefings — described in the meeting as a roughly 61 percent canopy figure — represented a countywide percentage and how that number was calculated. Planning staff responded that canopy is measured using vegetation-height thresholds in the LiDAR, and that the report's maps and appendices (including a grass-and-shrub map) clarify how prairie soils, agricultural lands and working forest lands are treated in the analysis.

Staff cautioned that the LiDAR-based method cannot always distinguish mature, structurally complex forest from recently planted, bush-sized saplings and said the analysis is therefore not a substitute for field-level forest assessments. "There are some disclaimers about, for example, in working forest areas some little baby trees are bush sized and therefore not counted as tree canopy," the staff member said.

Commissioners discussed how the assessment might be used. Staff noted the work will help prioritize restoration where multiple benefits can be stacked — for example, riparian planting to improve water quality or targeted restoration that contributes to carbon sequestration — and emphasized that different funding streams and regulatory tools typically apply to urban canopy and rural restoration. The presenter said the county holds a Department of Commerce grant focused on riparian management and that the tree canopy assessment will be one input for future programmatic and regulatory recommendations.

The presentation also raised implementation questions: commissioners asked whether the maps are discoverable via search, whether the data will be presented at the parcel level for permits and how prairie and private agricultural lands are flagged and protected. Planning staff said the report and the appendix materials are available online and that the county will continue to refine how search and web navigation returns the resource. The staff member offered to share tree-growth simulations and time-stamped visualizations to show potential future canopy scenarios.

What happens next: staff said the assessment will be used in the comprehensive plan update and other planning work, and they will continue conversations about how the maps should inform restoration priorities and regulatory choices.

(Attribution: Planning staff; Commissioner Kevin Pestinger; public commenters Bruce Anderson, Bonnie Glessing and Christy White.)