The U.S. Army Corps of Engineers says Dworshak Dam’s safety rating continues to improve.
The Corps on Monday told Clearwater County Commissioners that the 700-foot high structure ranks as “low risk” of failure – or 4 on a scale of 5, with 5 being the safest. The scale gauges risk by multiplying the probability of dam failure by the consequences of that failure. The dam was rated a 2 – or high risk – on the scale in 2007, stemming from water leaking through and under the 45-year-old dam.
The Corps agency has slowly worked to mitigate the leaks and clear clogged drains, and five years later, the safety rating was upgraded to 3 on the scale – or “moderate risk”.
Officials say the consequence criteria make it unlikely Dworshak will ever receive the safest rating on the scale, due to the more than 1 trillion gallons of water it contains that would devastate downstream communities if the dam were ever to fail. (Lewiston Tribune)
