http://plainsdaily.com/entry/possible-ft-peck-dam-failure-major-threat-to-missouri-flooding/
BISMARCK, ND - "The dam structures on the upper Missouri River are in great shape. There are no significant issues at this time," stated Mark Clark in an interview following this morning's flood update briefing in Bismarck, reiterating that the dams are constantly monitored and annually inspected. The Army Corps of Engineer's Natural Disaster Program Manager has been in Bismarck dealing with the Missouri River flooding issues.
But Bernard Shanks, an expert in land and resource management who has spent over four decades studying Missouri River management, questions whether or not that assessment is completely accurate. "I have followed this issue for 40 years, and I have never seen them more at-risk than they are today," Shanks told KMOX radio listeners in St. Louis, Missouri yesterday.
In an article appearing Tuesday in the St. Louis Post-Dispatch, Shanks stated his concerns about the ability of the Fort Peck Dam to withstand the increasing stress levels caused by record runoffs and precipitation over the course of the past year. Unlike the other 6 downstream dams, Fort Peck Dam is a "hydraulic-fill dam." Shank wrote that this is "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."
The risk associated with hydraulic-fill dams led California to outlaw them and require that all such dams be removed and rebuilt.
Current flooding exceeds the 500 year flood plain levels, with the snow pack still in the process of melting. The Army COE intends to continue raising release levels at the Garrison dam through June 18 up to 150,000 cfs, at which time they plan on holding the releases constant.
If the Fort Peck Dam were to fail under the pressure of heavy spring rains and the melting snowpack, which is forecast to hit the highest levels since 1898, far exceeding 1997 levels, Shanks warned that it could cause a domino effect failure in the downstream earthen dams, including the Garrison and Oahe dams, causing them to be overrun and cave under pressure.
"There would be a flood like you've never seen," Shanks said in yesterday's KMOX interview, warning of the possibility of "chest-high" flooding in that city. "It would be the most epic man-made disaster in the United States."
"I feel the Corps is doing everything they possibly can," said Clark today.
Clark also reminded those who would be quick to direct blame onto the Corps that, "We are operating in uncharted territory," experiencing record levels of rain and snow. "It is hard to second guess mother nature."
In the aftermath of Hurricane Katrina, a federal court ruled that the COE was in fact responsible for the levee breaks in New Orleans, heavily contributing to that disaster.
Bernard Shanks Flood Risk Editorial// |