High rainfall and raising water levels in all parts of the country are a grave concern to many people in every part of our country. I was curious about how damaging landslides actually are. Here is what I found. If you live anywhere near a river, you might want to pay attention to this bit of info I want to share. After you read this, I want you to think of what you can do to prepare in advance. What would you need to have if your town was suddenly threatened with a major disaster? Please comment and share your ideas.
Hazards » Landslides
What was the most expensive landslide to fix in the United States?
The Thistle, Utah, landslide cost in excess of $200 million dollars (1984 dollars) to fix. The landslide occurred during the spring of 1983, when unseasonably warm weather caused rapid snowmelt to saturate the slope. The landslide destroyed the railroad tracks of the Denver and Rio Grande Western Railway Company, and the adjacent Highway 89. It also flowed across the Spanish Fork River, forming a dam. The impounded river water inundated the small town of Thistle. The inhabitants of the town of Thistle, directly upstream from the landslide, were evacuated as the lake began to flood the town, and within a day the town was completely covered with water. Populations downstream from the dam were at risk because of the possible overtopping of the landslide by the lake. This could cause a catastrophic outburst of the dam with a massive flood downstream. Eventually, a drain system was engineered to drain the lake and avert the potential disaster.
Eventually the Thistle landslide reached a state of equilibrium across the valley, but fears of reactivation caused the railway to construct a tunnel through the bedrock around the slide zone at a cost of a million dollars. Also, the highway had to be realigned around the landslide. When the lake caused by the landslide was drained, the residual sediment partially buried the town and virtually no one returned to Thistle. This landslide is still moving, at present, although at a fairly slow rate. State officials continue to monitor this landslide.
Source:
University of Utah, 1984, Flooding and Landslides in Utah - an Economic Impact Analysis, University of Utah Bureau of Economic and Business, Utah Dept. of Community and Economic Development, and Utah Office of Planning and Budget, Salt Lake City, Utah, 123 p.
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