In today’s Press & Dakotan, I addressed whether the dams along the Missouri River are structurally sound. Colonel Robert Ruch, who overseas the dams, has probably begun every nightly teleconference this week with an assurance that the dams are fine.
QUESTION: Are the dams along the Missouri River structurally sound?
ANSWER: Colonel Robert Ruch (pronounced Rook), the commander of the Omaha district for the U.S. Army Corps of Engineers, stresses during a teleconference held daily with national, state and local officials, as well as journalists, that the mainstem dams along the Missouri River are structurally sound.
“There’s been a rumor every day (of problems with the dams),” he said Thursday. “You get calls in from the public that they heard this or that. I think the local and state officials have been doing a great job tamping them down.
“I have seen every dam this week — some of them operating at 150,000 cubic feet per second (cfs),” Ruch continued. “They are operating magnificently.”
He said there is danger in misinformation circulating about the dams.
“That’s one of the reasons we conduct this call every evening, so we can get the proper information out to the press, local governments and the public,” Ruch said.
QUESTION: Do we need to worry about flows being raised above 150,000 cfs any time it rains a few inches?
ANSWER: When setting 150,000 cfs as the peak for releases along the lower five mainstem dams, Jody Farhat, chief of the Corps’ Missouri River Basin Water Management Division in Omaha, Neb., said they looked beyond the above-normal snowpack that will enter the system in the next few months.
“We included some persistence of this above-normal precipitation continuing into June and July,” she said. “We feel we have captured the likely potential run-off. But, certainly, if we get events like we had in that third weekend in May where we got widespread areas of five to eight inches of rain, we don’t have that built in. But we have above-normal precipitation for the next two months built into our forecast.”
However, I have seen at least one man who has studied the dams for decades raise concerns that the likelihood of Fort Peck, especially, experiencing a failure increases with its age. That’s hardly a surprise.
Here is what Bernard Shanks, an adviser to the Resource Renewal Institute, wrote in St. Louis Today earlier this week. Needless to say, it created quite a stir.
The Fort Peck Dam is built with a flawed design that has suffered a well-known fate for this type of dam — liquefaction — in which saturated soil loses its stability. Hydraulic-fill dams are prone to almost instant collapse from stress or earthquakes. California required all hydraulic-fill dams be torn out or rebuilt — and no other large dams have been built this way since.
At three miles wide, Fort Peck Dam last opened its floodgates 36 years ago. By the end of the first week in June, the U.S. Army Corps of Engineers will be releasing a record spill of water. The corps recently answered the question of possible failure with a statement the dam is “absolutely safe.” It may be the largest at-risk dam in the nation.
What if Fort Peck Dam should fail?
Here is a likely scenario: Garrison, Oahe and three other downstream earthen dams would have to catch and hold a massive amount of water, an area covering nearly 250 square miles 100 feet deep. But earthen dams, when overtopped with floodwater, do not stand. They break and erode away, usually within an hour. All are full.
There is a possibility a failure of Fort Peck Dam could lead to a domino-like collapse of all five downstream dams. It probably would wreck every bridge, highway, pipeline and power line and split the heartland of the nation, leaving a gap 1,500 miles wide. Countless sewage treatment plants, toxic waste sites and even Superfund sites would be flushed downstream. The death toll and blow to our economy would be ghastly.
I’ve seen Shanks in follow-up interviews say that he is not predicting this will definitely happen. He is just saying it is a possibility given the design of Fort Peck and its age. Let’s hope Shanks doomsday scenario does not come to pass, because in that case the “Inland Voyage” would likely become the “Atlantic Ocean Voyage.” That wouldn’t be cool, as it no longer contains the Robert Louis Stevenson reference or the multiple interpretations of just what an inland voyage is …