Key changes proposed for Whitman County Critical Areas Ordinance include riparian methods and 'no net loss' standard

Consultant Douglas Yormick walked commissioners through substantive and technical changes in the draft Critical Areas Ordinance, citing Ecology and Washington Department of Fish & Wildlife recommendations. Several updated definitions were adopted or clarified, and the draft now contains an explicit "no net loss" mitigation objective.

On riparian areas, Yormick described two approaches to buffer widths and why the county’s eastern ecosystems merit a different method: "Type F are the fish habitat streams, so those widths are being reduced from 200 feet to 180 feet, and Type N streams those are now reduced to 100 feet and that is the minimum width necessary for water quality function," he said. The draft also adds an alternate approach using site potential tree height to tailor riparian widths in non-forested eastern landscapes.

Wetlands rules were updated to include a functionally disconnected-buffer standard to accommodate situations where a road or development bisects a buffer, and to add "preservation" as an acceptable form of compensatory mitigation alongside restoration and enhancement. The consultant said mitigation ratios and sequencing were adjusted to align with Ecology’s watershed approach.

Commission members pressed for clarity on several technical terms, including the definition of "highest adjacent grade" used in floodplain standards and how vernal pools and site‑specific ecosystem differences would be treated. Staff agreed to refine ambiguous language and return edits before finalizing the SEPA filing.