By Hal Bernton and Lornet Turnbull, The Seattle Times
SEATTLE—Searchers on Tuesday continued to recover the remains of victims from the muck of the deadly Snohomish County mudslide, but an official warned Tuesday the effort could be threatened by spring flooding.
Slide debris blocking the North Fork of the Stillaguamish River could divert the increased flows from snow runoff into a new channel along the route of state Highway 530, potentially threatening homes downstream, according to an operations official with a state incident-command team.
“There is a high probability that the river could end up flowing down what was the highway,” said Mike Asher, operations section chief for the state incident-command team in charge of the response effort.
To prevent the river from taking that course, state officials have asked the Army Corps of Engineers to come up with a plan to create an alternative channel that could safely handle the peak spring flows.
“They are the professionals,” Asher said Tuesday. “They have the ability to build berms and dikes; whatever it takes to control the direction of the floodwaters.”
Asher said he is hopeful that the Corps can come up with a plan within the next few days.
The March 22 mudslide slammed down from a slope on the north side of the river and barreled across the channel, leaving behind massive amounts of debris.
Some water is flowing around the debris.
But a lot of it remains pooled up behind debris at depths that are 25 feet above normal river levels. Searchers believe human remains are located in some of these areas, but it’s too dangerous to search until some sort of channel is created to improve flows, Asher said.
The risks will rise during spring runoff, which is expected to increase flows fourfold as warmer temperatures melt a heavy snowpack that blankets surrounding slopes.
The high water is expected to pile up even more debris, which officials fear could divert the river into a channel along the slide-ravaged Highway 530 and threaten downstream property.
On Tuesday, the Snohomish County Medical Examiner’s Office said the death toll for the Oso-area mudslide had climbed to 28, an increase from the 24 reported Monday.
The number of missing has dropped to 20.
The number of victims is expected to increase Wednesday during the twice-daily updates provided by the Medical Examiner’s Office. Search officials confirmed they had recovered additional remains during Tuesday’s search.
In addition to the unmeasurable and mounting toll in lives, the cost of damage and cleanup from the Snohomish County mudslide is expected to exceed $42 million.
As the governor’s office asked President Barack Obama to declare the slide a “major disaster,” paving the way for federal aid for victims, it estimated the cost of debris removal at $22 million and the cost of search and recovery operations at more than $10 million.
That amount does not include the nearly $10 million in direct losses, including $3.4 million for lost personal property, cited in Gov. Jay Inslee’s Monday letter seeking the declaration to secure federal aid to individual victims who survived the mudslide or lost their homes in it.
The estimates do not include the cost of repairing Highway 530.