Snohomish County Council to review stream buffer rules after state hearing board ruling

The Snohomish County Planning Commission will hold a public hearing on the county's Critical Areas Regulation at 5:30 p.m. on Tuesday, October 27.

The hearing follows a February 17, 2026, decision by the Washington State Growth Management Hearing Board. The board ruled that the county's amended regulations, passed in May 2025, failed to protect the functions and values of critical areas using the best available science. The board directed the county to address these deficiencies by the end of 2026.

The dispute centers on the size of riparian buffers, or protected zones between new development and water bodies. In 2025, the County Council amended the regulation to permit the filling of small wetlands and reduced the required buffer sizes. Tom Murdoch, director emeritus of the Adopt A Stream Foundation, notes that these changes impact the health of local waterways.

Murdoch has monitored North Creek since 1978, when it flowed year-round and supported dense salmon runs in McCollum Park. By the summer of 1987, the creek began drying out for weeks. Today, there is no stream flow between mid-May and late October. Murdoch attributes this decline primarily to the conversion of forests and wetlands into residential and commercial development. More than 60 percent of the upstream watershed is now covered by hard surfaces, preventing rainwater from soaking into the ground.

Futurewise, the League of Women Voters of Snohomish County, Pilchuck Audubon, the Sno-Isle Chapter of the Sierra Club, and the Adopt A Stream Foundation challenged the 2025 amendment to the state hearing board. Murdoch recommends that the council adopt a buffer width based on one 200-year site-potential tree height, measured from the active channel or floodplain. For administrative simplicity, he suggests the county use 200 feet as the standard measurement. He also advises that new construction adjacent to critical areas employ low impact development techniques.

Residents can share their views at the Planning Commission hearing on October 27 or submit comments online. The county's website provides details on how to participate. The County Council has not yet scheduled its own hearing on the matter. To receive notification when that date is set, individuals can call the council office at 425-388-3494 and request to be added as a party of record.

The Planning Commission will prepare recommendations for the County Council based on the public input received at the October 27 hearing. The council will then consider those recommendations as it works to meet the state's directive to revise the regulations by the end of the year.