Thurston County commission reviews geologic-hazards code update, debates 400-foot permit trigger

Blair, a county staff member, presented a draft overhaul of Thurston County’s geologically hazardous areas chapter during the Planning Commission’s March 4 meeting, laying out a plan to centralize designations and standards, tie triggers to public mapping and clarify levels of geotechnical investigation.

The presentation emphasized use of new DNR landslide mapping and updated soil data to identify hazardous features and said the draft would create clear review pathways so property owners can determine whether a critical areas review permit (CARP) is required and what level of geotechnical report would be needed. "We're referencing the new DNR landslide mapping," Blair said, noting the mapping and NRCS soil information will help target reviews where risk is highest.

The draft currently triggers a CARP for development proposals within 400 feet of mapped hazard features, a distance staff said is larger than most neighboring jurisdictions. Commissioners and members of the public questioned that threshold. Commissioner Kevin Pestinger asked for data on how many applications would be affected; staff said Mark Beaver, the county reviewer, handles roughly three to six geotechnical reports a week and that moving the trigger to 200 feet would likely reduce that workload, though precise counts were not yet available.

Several public commenters urged the commission to slow the process and provide clearer materials. Christie White, who identified herself as a Delphi Valley resident, asked that "chapters 24.15, biological hazards, and 24.16, seismic hazards of the CAO not move forward at this time" and provided a checklist the county could use to improve public review (redlines, plain-language chapter summaries, best-available-science citations and a glossary).

Staff and commissioners supported providing both a clean draft and a mark-up or summary appendix highlighting substantive changes for nontechnical reviewers, and discussed adding a glossary and a cover sheet that flags which sections have substantive changes versus those that carry forward existing language.

On mitigation and measurement, staff described a parallel, grant-funded project with the Thurston Conservation District to develop a landscape-scale framework for evaluating no-net-loss and potential net-gain in ecosystem function. Staff said the county received approximately $500,000 from the Department of Commerce (climate-commitment funds via the salmon recovery and local planning grant program) to scope work for that effort and would produce a scope of work to the Department of Commerce.

Commissioners debated the balance between environmental protections and homeowner costs. Staff noted the draft also seeks to provide a spectrum of required geotechnical work — from short letters to detailed reports — so applicants and reviewers better understand expected costs. The commission discussed whether to favor a 200-foot CARP trigger, which several members said would better match coastal setbacks used in the county’s shoreline master plan, rather than the 400-foot trigger in the current draft.

Blair said the code also allows for standard buffers (e.g., a 50-foot minimum or a 45-degree slope-based buffer) and for higher-level geotechnical investigation to justify reduced setbacks; reasonable-use exceptions would still apply if applicants seek to go inside recommended buffers.

Staff said the next meeting will cover frequently flooded areas and critical aquifer recharge chapters, with flood-area updates expected to prompt more substantive discussion. The meeting closed after brief personnel announcements about new hires.

What happens next: staff will return with additional data on how many permits would be affected at different buffer distances, examples of the proposed cover sheet/matrix and follow-up presentations on the next CAO chapters.