Kansas Reservoirs Are Filling Up With Dirt, And It Won't Be Easy To Clean Up
HARTFORD, Kansas — Some of Kansas’ major reservoirs are filling up with sediment, and if something isn’t done to address the issue, parts of eastern Kansas could see water shortages and insufficient flood control as soon as 30 years from now.
To help slow down the slow, but consistent, reduction of usable water storage in Kansas’ reservoirs, the Kansas Water Office is trying to help farmers in critical areas upstream of the lakes to reduce the water running off from their fields.
But if that isn’t widely accepted, state officials say taxpayers may have to pay millions more just to keep the water flowing.
Sediment collecting in reservoirs is a part of the natural lifespan of a water system. But in several Kansas reservoirs, it’s already drastically reduced their originally designed capacity and lifespan — more than 40% in the Kanapolis, Tuttle Creek, John Redmond and Toronto reservoirs.
“That means when we get into a drought, that’s 40% less water that we have available to make it through that drought,” said Earl Lewis, acting director of the Kansas Water Office. “So, that’s a significant problem.”
During the 2019 legislative session, lawmakers approved $700,000 for the Kansas Reservoir Protection Initiative.
The program works with farmers in key areas upstream of Fall River, Kanopolis, John Redmond and Tuttle Creek to help pay for land management practices such as terracing, putting in grass between fields and creeks and planting cover crops.
These practices are meant to help the soil in these areas better soak up water from heavy rains — water that otherwise runs off fields into nearby creeks and streams. The runoff carries excessive amounts of nutrients and sediment, which ends up at the reservoirs.
Rex Truelove used the program to get help paying for cover crops on his farm near Hartford. In his case, it’s a mix of rye, radish and turnips.
Truelove planted the crops between the times he plants his traditional corn and soybean rotation.
“The more time you can have something green on the ground that’s what Mamma Nature wants,” said Truelove, whose land is north of John Redmond reservoir.
During a demonstration at Truelove’s field, Andrew Lyon from the Kansas Department of Health and Environment’s watershed restoration and protection strategy program pulled out a shovel, dug up a radish and explained how cover crops reduce sediment problems downstream.
“It’s the root channels that grow that really allow water to then infiltrate into the soil,” he said. “It’s just huge for getting the water into the ground and not running off over the top of the ground.”
This is particularly important during heavy rains — 3 to 4 inches in an hour — that are increasingly more likely in eastern Kansas due to climate change.
Cover crops are also possibly beneficial for farmers. Up the road, Kevin Mautz showed how he’s used the program to save money.
He uses some of his fields to graze cattle, and planting cover crops has provided extra food beyond the leftover corn stalks — which means he can purchase less hay.
“I don’t have to feed ’em,” Mautz said. “They’re just content out here.”
The Kansas Water Office’s Earl Lewis said the program’s current level of funding isn’t nearly enough to solve the problem from a watershed scale.
But he hopes by finding early adopters, he can prove to reluctant farmers it can be mutually beneficial. If not, the consequences could be huge.
Saving Tuttle Creek
The state has already spent $20 million dollars to dredge (that is, physically remove sediment) from John Redmond reservoir, southeast of Emporia.
Tuttle Creek, which is a major part of the Kansas River basin system, could be the next candidate. Sediment has reduced its original storage capacity by 47.9%.
Not only does it provide important flood storage, but Tuttle Creek also is a source of northeastern Kansas’ agriculture and public drinking water systems.
The Kansas Water Office estimates that, at current sedimentation rates, the basin will not be able to meet the water demand of the area during a drought as early as 2057.
“We want them to be fully functional for 400, 500 years,” Lewis said. “We need to figure out how to get us to a much more sustainable situation where we have those reservoirs for the long-term.”
In the meantime, researchers are studying the best way to mitigate the problem. While reducing sediment entering the reservoir in the first place is a start, at some point, sediment will have to be removed.
Rather than use traditional dredging, which could cost an estimated $39 million a year at Tuttle Creek, engineers are looking at a new method called water injection dredging.
It shoots high-pressure jets of water into the sediment, which stirs the sediment up and allows it to naturally flow through the dam’s outlet and through the Kansas River as it would have before the dam.
While early tests show this technique would work with the kind of sediment in Tuttle Creek, researchers are less certain they can get it to flow downstream.
For now, the state is going to keep doing what it can with its limited resources. Fixing a problem that’s 40 years down the road is a hard sell, Lewis said, but it will only be worse in the future.
“The amount of money we spent at John Redmond,” Lewis said, “would pale compared to what we’d end up doing at Tuttle Creek.”
Brian Grimmett reports on the environment, energy and natural resources for KMUW in Wichita and the Kansas News Service. You can follow him on Twitter @briangrimmett or email him at grimmett (at) kmuw (dot) org. The Kansas News Service is a collaboration of KCUR, Kansas Public Radio, KMUW and High Plains Public Radio focused on the health and well-being of Kansans, their communities and civic life.
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