Q: Why has outflow from Tuttle Creek Lake slowed? And what’s going on with the construction projects there?
A: With record-setting rainfall near the Dakotas earlier this month finally making its way through the Missouri River, you can imagine that the space all its tributaries share is becoming pretty full.
That water is currently flowing past Waverly, Missouri, which is the low-lying area that helps U.S. Army Corps of Engineers officials determine whether there is room in the channel to release more water from upstream lakes. Tuttle Creek is one of those lakes.
The National Weather Service observed the flow at Waverly to be 156,000 cfs as of Friday morning. Once that flow drops below 140,000 cubic feet per second, the Kansas River Basin reserviors will be able to release more water.
Officials want to drop the reserviors’ water levels down to their normal levels before the first winter freeze.
Lake officials said once that surge passes and space opens up once more, Tuttle Creek Lake should be able to increase its outflow again.
“If, during this time, the lake goes above elevation 1,114.4 feet, our release criteria at Waverly will increase from 140,000 to 180,000 cfs, and we should likewise be able to increase outflow,” officials wrote on Facebook. “Let’s hope we can keep the lake from going much higher (barring any significant rainfall in the Tuttle Creek basin).”
According to the current three-day forecast for releases, Tuttle Creek is expected to increase its outflow to 3,000 cfs starting Saturday.
“The front edge of that water is east of Kansas City and the back edge of that water is just upstream of Kansas City,” said Brian McNulty, the Corps’ operation project manager at Tuttle Creek. “With us starting up our releases, we’ll be timing the arrival of our water as the tail end of that passes Kansas City.”
According to the Corps’ Thursday’s reading, the outflow of the lake is 200 cubic feet per second, where it has remained for the past week. Lake elevation is at 1,113.43 feet, about 38.43 feet above its normal pool level, and its inflow is about 9,500 cfs.
In the meantime, McNulty said people should be aware of where they boat as the Corps does not technically own the property for some of the land that has been flooded; rather it has obtained flowage easements. McNulty said boating on those areas of private property would be considered trespassing. Most of those areas are above the Kansas Highway 16 bridge near Randolph, or the northern end of Riley and Pottawatomie counties and the southern end of Marshall County.
As for construction at the dam, the bulk of the work has halted since the summer as waters rose to peak levels, and Corps officials anticipated high releases from the tubes.
One of the projects, which rehabilitates the stilling basin, includes removing and replacing concrete, as well as excavating land outside the basin walls. It also includes installing additional anchoring to strengthen the basin wall system.
The project is at least half done, but until the lake gets down to a more stable level, the contractor will remain offsite. McNulty said officials hope to have workers back this fall.
“For part of their work, we also have to draw down the river pond area, draw down the stilling basin, and we have to shut off our releases from the lake,” McNulty said. “That’s one of the reasons they haven’t been back onsite. They’re establishing their schedule to coordinate with our releases and evacuation of the rest of our floodwater with their work.”
A little bit of work is still being done around the spillway gates to eventually replace the gate controls. McNulty said workers cannot actually work on the gate itself and electrical portion of the project until the lake drops at least another 10 feet, but they are able to work on lighting improvements for now.
None of the projects will affect the normal operation or integrity of the dam except when the river pond below Tuttle Creek Dam will be lowered for a period of time for the stilling basin project.
In June, Kansas Highway 13 over Tuttle Creek Dam reopened after 15 months of construction. The Corps completed a bridge deck replacement project over the dam’s spillway gates. The bridge connects Riley and Pottawatomie counties.
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