The U.S. Army Corps of Engineers is using the spillway and increasing output from the Garrison Dam within the next two weeks. Changes to the Missouri River channel, however, led the corps to lower its projected river level in Bismarck.
The dam is releasing 80,000 cubic feet per second (cfs) and the water in Bismarck is just below flood stage at 15.8 feet. Output from the dam will eventually reach 150,000 cfs, raising the water level to 20.6 feet in Bismarck.
The corps intends to release 85,000 cfs on Monday, 105,000 cfs on Wednesday and 120,000 cfs on Thursday, said Todd Lindquist, the operations manager for the Garrison Dam. It intends to hold the release at 120,000 cfs for about a week before raising it to 150,000 cfs in mid-June. The 150,000 cfs releases could go into July.
"The river itself has increased capacity to handle the increased flow of water," Gov. Jack Dalrymple said during a press conference Saturday evening.
The new water level is lower than earlier projections that had less output from the dam. The model did not account for the increase in flow changing the depth of the river channel.
"We will use a combination of all the avenues available to get the excess water out," Lindquist said. "It will go through the spillway gate. It is still a controlled release."
U.S. Geological Survey stream gauges in the Bismarck area show the water in the Missouri River is flowing about 16 feet per minute, or about seven to eight times greater than normal, said North Dakota National Guard Adj. Gen. David Sprynczynatyk. The faster the water moves, the greater its capacity to carry sediment.
"For many years, people asked why we can't clean out all this sand," Morton County Commissioner Bruce Strinden said. "This really is a big flush. Most of us expected at this point to be at 17 feet."
In the meantime, Bismarck is continuing to build a levee to protect parts of south Bismarck. The contractor was given a five-day completion schedule for the levee, but it is being constructed in phases. It will be built to the maximum water level, plus 1 foot. Officials are uncertain how big of a window they have for completing the levees.
Burleigh County is protecting its water system and the roads that access that system.
"What we could do is not feasible or we're running out of time," Burleigh County Commissioner Brian Bitner said. At this point, levees are not being constructed in the county to protect residential areas, with the exception of a levee on South 48th Avenue from the intersection of Sibley Drive and west to the river.
The Burleigh County Commission met in a special meeting after the flood update to discuss levee projects. The commission decided not to move forward on levees that would have protected homes in Misty Waters, Briardale, Hoge Island and parts of Fox Island, Commissioner Mark Armstrong said. This affects about 1,334 homes and about 5,600 residents, he said.
Morton County also is focused on protecting its public infrastructure, such as the wastewater treatment plant. Otherwise, it does not intend to install dikes, Strinden said.
"Some (developments) are almost impossible to dike," he said.
The corps did not recommend dikes in parts of Morton County and Mandan. Residents in south Mandan, in the Lakewood, Harbor View and Marina Bay additions, are concerned about this decision. The corps told the city that surface flooding was not so much an issue as ground water seepage, Mandan Mayor Tim Helbling said. A voluntary evacuation for Jetty Beach was put in place on Saturday.
"We talked about blocking off the channels to the three bays," Helbling said. "The corps' hydro experts concluded it was feasible, but the water would equalize between the two points."
Sandbagging efforts continue on both sides of the river. The National Guard has 1,500 members in Bismarck filling sandbags, directing traffic and helping with other flood relief efforts. The Guard will deliver filled sandbags to neighborhoods, if calls for sandbags are received at the emergency operations center. The operations center number in Burleigh is 355-1659 and Morton County is 667-3307.
Earlier Saturday, officials came under criticism after a briefing scheduled for 1 p.m. was delayed until 5:30. Bismarck Mayor John Warford said the delay was the result of the corps evaluating new numbers. Warford and other officials did spend time fielding questions from concerned residents.
About 50 people attended the meeting Saturday evening. Government officials in attendance included Dalrymple, Spyrnczynatyk, Helbling, Bitner, Strinden and Warford. There will be a flood update at 4 p.m. today and 4 p.m. Tuesday. No meeting will be held Monday.
(Reach reporter Sara Kincaid at 250-8251 or firstname.lastname@example.org.)