Yakima County, WA Environmental Rules: Erosion Control (2026)

The Washington Legislature's Growth Management Act, not a locally invented ordinance, is the origin of Yakima County's erosion and geologic-hazard protections. RCW 36.70A.060(2) commands that each county and city shall adopt development regulations that protect critical areas that are required to be designated under RCW 36.70A.170, with a compliance deadline of September 1, 1991 for counties and cities that plan under RCW 36.70A.040, or March 1, 1992 for the rest. The same chapter's definitions section, RCW 36.70A.030(12), defines critical areas to include wetlands, aquifer recharge areas, fish and wildlife habitat conservation areas, frequently flooded areas, and geologically hazardous areas, the last of which is the category state planning guidance uses to capture erosion hazard areas, landslide hazard areas, and other unstable slopes. Subsection (1) of the same section separately requires regulations conserving agricultural, forest, and mineral resource lands and requires plats and building permits within 500 feet of those lands to carry a notice of nearby resource activity; subsection (3) requires counties to review and, if needed, revise both the critical-area designations and the regulations whenever comprehensive plans are updated; and subsection (4) lets a city under 25,000 residents adopt its county's critical areas regulations by reference instead of writing its own.

Yakima County met the RCW 36.70A.060(2) mandate by adopting Title 16C, its Critical Areas Ordinance, which today houses the county's geologically hazardous area and flood hazard standards. An editor's note in the county code confirms that as of the October 1, 1995 effective date of Ordinance 8-1995, the flood-hazard rules formerly codified in Division II of Title 16 were repealed and folded into Chapters 16C.05.20 through 16C.05.72 of Title 16C. The statute itself also builds in an appeal path for disputes over whether a jurisdiction's critical-area regulations comply with the Act: a petition challenging a Department of Commerce compliance determination goes to the Growth Management Hearings Board within 60 days of the decision, per RCW 36.70A.060(1)(d)(iii).