SIOUX FALLS, S.D. (AP) - Releases from Gavin's Point Dam in Yankton were bumped up to record amounts on Tuesday, the final planned increase in South Dakota to move more water down the bloated Missouri River, state officials said Tuesday.
The U.S. Army Corps of Engineers was pushing 150,000 cubic feet of water per second through the river's dams, the equivalent of 1 ½ times the average daytime flow rate over Niagara Falls in the summer tourism season. The goal was to get rid of unexpectedly heavy rains that fell last month upstream in eastern Montana and Wyoming and western North Dakota and South Dakota.
Kristi Turman, director of the South Dakota Office of Emergency Management, said the releases were increased by the corps at 8 a.m. Tuesday.
It should take about a day for those higher flows to reach Dakota Dunes, where crews have spent weeks building levees to protect the community from the rising Missouri.
Crews in Dakota Dunes, a southeastern South Dakota community of about 2,500 people, have put in a series of pumps to push groundwater over the levee, but there's a limit to how much groundwater can be sent out as too much dewatering weakens the levee structure.
About half of the 2,500 residents have been evacuated from their homes.
Levees have been holding strong in the Pierre and Fort Pierre areas, where releases earlier were increased to record levels on Oahe Dam a few miles upstream.
Pierre Mayor Laurie Gill said city officials are studying what else might be necessary to prevent flooding in the next few months.
"There's a lot of variables we don't know," Gill said. "We're still analyzing what else we can do in the community. Is there anything else we can do for preventive measures?"
On Tuesday, the Pierre Capital Journal newspaper reported that Fort Pierre Public Works Director Brad Lawrence sent a series of emails to a Washington, D.C., agency in February predicting "a flood of biblical proportions" if the U.S. Army Corps of engineers did not start releasing water from the Oahe Dam.
The emails sent to Kevin Morley of the American Water Works Association said the corps had failed to evacuate enough water from the main stem reservoirs to meet normal runoff conditions, and "this year's runoff will be anything but normal."
According to the corps, no one at the Omaha, Neb., office, which coordinates activities on the Missouri River system, was ever forwarded the emails.
Associated Press Writer Chet Brokaw contributed to this report from Pierre, S.D.
Online:
Pierre (S.D.) Capital Journal: Email warned of "biblical flood'