Landslide Experts Walk Back Time Estimate For Rattlesnake Ridge Slide
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Geology experts with Washington’s Department of Natural Resource have quit making predictions for when a slow-moving landslide near Yakima might break loose.
About 20 acres of the hillside are in motion near Union Gap, just south of Yakima.
DNR Hazards Geologist Stephen Slaughter briefed a state Senate committee about the Rattlesnake Ridge slide Monday.
Slaughter walked back a previous estimate of early March for when the hillside most likely would collapse into a quarry pit at its base.
“It could potentially run out a little farther. It could just stop,” Slaughter said. “Landslides are really poorly understood, this one especially because we can’t get in the subsurface.”
SEE MORE:
– State DNR Rattlesnake Ridge page
– Yakima County landslide information page
Slaughter said there is no sign that groundwater is lubricating the underside of the sliding layer of basalt rock. Water is normally a factor in landslides.
“It could self-arrest potentially,” he said.
About 65 people living at the base of the ridge have heeded government warnings and evacuated to hotels or other temporary housing.
Slaughter said the thing that made the monitoring team uncertain is that the slide stopped accelerating. It’s now grinding downslope at 1.6 feet per week.
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Still Sliding, Just Not So Fast: What’s Up With The Rattlesnake Ridge Landslide One Year Later
At this time last year, authorities in Central Washington were on high alert because of the slow-moving Rattlesnake Ridge landslide near Yakima. A year later, what’s changed? The landslide isn’t quite over – yet. But it has slowed down significantly.
Yakima County Closes Road Near Rattlesnake Ridge Indefinitely
Yakima County Commissioners voted this week to officially close a road at the base of the slow-moving Rattlesnake Ridge landslide in Union Gap.
For Displaced Rattlesnake Ridge Residents, Emergency Goes On As They’re Told To Return Home
The emergency is over for now at Rattlesnake Ridge near Yakima. The state says a major, sudden landslide is no longer imminent, and Yakima County has lifted its evacuation order and told residents they can move back home. But that’s easier said than done.
