Yakima County officials fear a temporary local road at the Naches landslide will be washed out this winter by a rising Naches River, isolating residents in the Nile Valley.

Yakima County officials fear a temporary local road at the Naches landslide will be washed out this winter by a rising Naches River, isolating residents in the Nile Valley.

The Yakima Herald-Republic reports the county is asking the Corps of Engineers for advice on creating a new river channel.

The river was forced out of its channel by Sunday’s slide that also blocked Highway 410.

The Seattle Times reports the Department of Natural Resources warned a gravel pit operator in 2005 that digging was creating a hazard at a site near where the slide occurred.

The owner of Simmons and Son Hauling and Rock Crushing, Robin Simmons, said a geological study conducted for the company in 2007 found no reason for concern.

On Wednesday, state Transportation Department crews completed raising 1,000 feet of the Nile Loop Road with six new culverts to handle water. Officials estimate the emergency road will last six weeks at most.

But if higher river flows breach the road, building a permanent road will be more difficult.

County Public Service Director Vern Redifer says the county is negotiating with three property owners to create a wider river channel. About a dozen homes are in the area.

The Northwest Insurance Council says the Naches landslide is a reminder that damages from landslides and earthquakes are excluded from standard homeowner and business insurance. Special coverage is available that would cost about $1,000 a year for the owner of a $300,000 home.

The Transportation Department is drilling to determine the cause of the Naches slide. Landslide expert David Montgomery at the University of Washington told The Seattle Times the gravel pit can’t be ruled out.

The Department of Natural Resources had sent Simmons a succession of letters insisting on a plan for regular monitoring of the slope. The most recent was in July 2008. State geologist Dave Norman said the agency had been frustrated with the mine owners’ reluctance to comply.

Records show the owners appealed to State Rep. Jim Clements, who organized a meeting with DNR officials, including then-Lands Commissioner Doug Sutherland. Norman says Clements urged the gravel pit owners to cooperate with the department.

Highway 410 is expected to remain closed at Nachez through the winter.

(with information from Yakima Herald-Republic, The Seattle Times)