In this 2007, file photo Frank "Jerry" deNoyelles, KU ecology professor of the Kansas Biological Survey, launches a boat off the banks of Kanopolis Lake southwest of Salina. DeNoyelles is part of a team of researchers that is measuring the silt filling up Kansas reservoirs. by Alex Parker
TOPEKA, Kan. (AP) — Two federal reservoirs in Kansas have been losing significant amounts of water storage capacity because of sedimentation, according to a study that the U.S. Geological Survey says also shows the reservoirs can't be expected to last indefinitely.
At least 95 percent of the sediment that flowed into Kanopolis Lake and Tuttle Creek reservoirs stayed in those reservoirs from October 2008 through September 2010, according to the study, which was conducted by the USGS and the Kansas Water Office.
The study ran from October 2008 to September 2010. Kyle Juracek, a research hydrologist who conducted the study, said water storage at Kanopolis, which is located outside Salina in central Kansas, has dropped 34 percent since the reservoir was created in 1948. Tuttle Creek reservoir, located near Manhattan in northeast Kansas, saw storage drop 43 percent since its creation in 1962. (An earlier version of this story implied the reservoirs had lost significant water storage during the study. That is incorrect.)
"This USGS study demonstrates that the useful lifetime for the valuable services of man-made reservoirs ... is measured in mere decades because they interrupt the natural sediment-transport process," Marcia McNutt, USGS director, said in a statement.
Kanopolis and Tuttle Creek reservoirs were built more than 50 years ago for water storage, flood control and recreation.
The study said the sediment came from the banks of upstream waterways, surface soil erosion and erosion along the banks of the reservoirs themselves. During the study period, about 600 million pounds of sediment flowed into Kanopolis, which was built in 1948. But about 31 million pounds flowed out. About 13 billion pounds of sediment flowed into Tuttle Creek reservoir during the two years, with about 327 million pounds flowing out. Tuttle Creek reservoir was built in 1963.
The study was expected to help the Kansas Water Office, which helps coordinate water planning in Kansas with the Kansas Water Authority, evaluate how best to manage sediment problems for the reservoirs.
Tracy Streeter, director of the Kansas Water Office, said in an email Tuesday that both reservoirs are important to Kansas and that the state has been looking at long-term water supply and demand issues and how best to slow sedimentation. Kansas also expects to use these reservoirs for water storage and supply "for several decades," he said.
"Good sites to build reservoirs are not plentiful in Kansas and the location of current reservoirs are really the best available," Streeter said. "In order to provide water supply for our citizens for the long term, we must treat these reservoirs as critical infrastructure that needs to be maintained."
Comments
Ron Holzwarth 1 year, 6 months ago
My grandfather had a rather large dam constructed in his pasture in western Kansas many years go, I think in the 1930s.
And I certainly do remember the day we went to look at it in 1959. That was the way it went completely dry, and all that was there was some dead fish lying on a very large flat plain.
For quite a few years, whenever there had been a big rainstorm, the big event was to go look to see if there was any water in the dam. Quite a few times, my grandmother would call and excitedly say, "There's even water in the dam!"
Meaning, there had been quite a lot of rain, and being farmers, that was of great interest.
It had taken only 25 years for the dam to completely fill up with sediment. There was one advantage, though. I remember my Dad planting wheat all over it one year, and since the soil was so fertile and what was left of the dam collected a lot of water, the yield was incredible.
Then, the dam eroded away at the spillway. The last time I was there I looked at the very large canyon that had eroded into the sediment at the bottom of the reservoir.
culturechange 1 year, 6 months ago
This was reported earlier this year. It is not all bad though. If the lake did not catch the sediment, it would have been washed out and lost completely. It is still in KS.
They aren't going to have much choice but dig out the sediment during dry years when the lakes are low. This sediment is rich topsoil and very productive. KS still has to have lakes for water storage or all our water will run off and leave us without water in the dry seasons.
They could construct some kind of sediment trap in the upstream rivers. This could then be drained and dredged periodically. The intercoastal waterway along the Gulf Coast fills up with sediment too and they drudge it continuously.
Mark Jakubauskas 1 year, 6 months ago
"This sediment is rich topsoil..."
Well, no.
It's mostly clay. Not too different from what you'd use in a ceramics class. Not much sand, or organic matter, certainly. When it dries, it sets like rock. More useful for making flower pots and kitty litter than as topsoil.
Ron Holzwarth 1 year, 6 months ago
"This sediment is rich topsoil and very productive." - - - > "It's mostly clay."
If it's more clay, all any farmer could say is: "Bring it on, Buddy!"
You should have seen the wheat crop that my father grew in the sediment on the bottom of my grandfather's dam. It was amazing!
elarson 1 year, 6 months ago
And "aggregate extractors" want to take more sand from the riverbed of the Kansas River than has been allowable since the Regulatory Plan was put in place in 1991!
What does this have to do with the siltation of the reservoirs? That's where they can find the sand. When dams are closed, any sediment in the water that enters the lake and sits there until the dam is opened, has time to settle to the bottom of the lake. A natual flow of sand and sediment down the river does not exist anymore. The river, seeking equilibrium, eats away at the riverbanks, taking from landowners. The USACE needs to try and create a more natural flow of dammed streams, irregardless of approaching holiday weekends, so the reservoirs can serve the purpose of flood control.
Mark Jakubauskas 1 year, 6 months ago
"What does this have to do with the siltation of the reservoirs? That's where they can find the sand."
Well, actually, most of what's in the reservoirs is silt and clay, not sand......
distant_voice 1 year, 6 months ago
This isn't a sudden discovery. Environmentalists warned about this part of damming rivers 50 years ago. Hydrologists had warned this was occurring in Kansas reservoirs thirty years ago. But just like global warming, we all assumed it was B.S. and ignored it.
LesBlevins 1 year, 5 months ago
Buffer strip plantings are the only available way to stop soil erosion, but taking crop land out of food production is a big no-no to Kansas Senators who want low food prices even at the destruction of the environment that produces the food. The only way to plant buffer strips without taking land out of production is to produce biomass for use as fuels in the buffer strips, trouble is producing biomass for energy generation is a big no-no to Kansas Senators who oppose alternative energy encroaching on fossil fuels consumption.
Commenting has been disabled for this item.