EVERETT — Snohomish County will take at least two more weeks before deciding whether to make emergency changes in how it handles land-use decisions after the deadly March 22 mudslide in Oso.
The County Council on Monday tabled discussion of options including a moratorium on new home construction in areas with known landslide hazards.
The move came after Deputy County Executive Mark Ericks asked for time to review temporary measures that council staff have been developing, which would increase building setbacks and engineering studies in potential landslide hazard areas.
“Let’s be deliberative and careful,” County Council member Brian Sullivan said.
Council Chairman Dave Somers started the discussion April 23, when he asked the council to consider a temporary home-building ban within a half mile of slide areas.
The council took no action last week. Somers on Monday said that after seeing a map of the proposed half-mile moratorium, the measure would have been overly broad. Most of the unincorporated areas of the county would have been off limits to new building while notoriously flood-prone river valleys would have been unaffected.
Somers urged the council to consider an amended proposal for temporary development controls designed to make building near landslide hazard areas more safe.
The county’s existing regulations, developed long before the March 22 slide, generally require buildings be set back at least 50 feet or half the height of an identified landslide hazard slope, whichever is greater.
Somers’ amended proposal would require buildings to be set back at a distance equal to double the slope’s height. Moreover, no permits would be issued without a geotechnical engineer examining potential risk out to a distance the equivalent of four times the slope’s height.
The plan also would enact landslide risk notification requirements for affected properties.
Somers also serves on the state Forest Practice Board, which has scheduled a special meeting May 12 to examine what is known — and what is not — about the Oso mudslide. There may be an opportunity for the county to work with the state in getting answers, he said.
The portion of the hillside that collapsed above Steelhead Drive was roughly 600 feet high. It sent debris at least 3,700 feet from where the toe of the hill had previously been at the edge of the North Fork Stillaguamish River. Slide damage in the valley stretched a mile from the hillside, and some of that area also was buried under flood water because the river was blocked by earth.
Councilman Ken Klein, whose district includes Oso, said that whatever happens next he wants to make sure people affected by the decisions get the opportunity to weigh in.
Joan Smith, of Edmonds, urged the council to look closely at the stability of hillsides between Mukilteo and Shoreline. All one needs to do is monitor the regular cancellations of Sounder commuter trains to understand just how prone to slides the area can be, she said.
Scott North: 425-339-3431; firstname.lastname@example.org.