Dry and Drier: Nebraska's largest lake shows early signs of drought

Lake McConaughy seen from the International Space Station in 1989 (Photo: NASA)
Water flowing through the irrigation system fed by Lake McConaughy. (Photo: Bill Kelly/NET News)
Kingsley Dam Control Tower at Lake McConaughy (Photo: Bill Kelly/NET News)
East end of Lake McConaughy. (Photo: Bill Kelly/NET News)
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May 9, 2013 - 6:30am

Climate experts in the United States are predicting only “limited improvement” of drought conditions in the Great Plains, including Nebraska in the coming months.  Cool, damp weather since the beginning of April in portions of the state have added moisture to surface soil but has provided only a fraction of the water needed to recharge area lakes, streams.  In addition, the U.S. Geological Survey reports that nearly a third of the 3400 wells measured in Nebraska show “below normal” or “much below normal” levels of groundwater.

These are key indications that much of Nebraska faces another year of drought, effecting both rural and urban residents. 

Especially in dry years news reports in the state closely follow the rise and fall of water levels is Nebraska’s largest body of water, Lake McConaughy.  This massive reservoir, built in the 1930s as a source of water for irrigation and electric power generation, is said to be the only landmark in the state clearly visible from outer space.   With so much water prone to fluctuation, the lake has become something of a barometer for measuring drought.

Even so, those responsible for managing and maintain the lake at the Central Nebraska Public Power District (CPPD) claim it doesn’t reveal everything about how a dry spell may affect the entire state. 

The lake water is held in place by three miles of dirt, rock and clay that make up Kingsley Dam.  Visitors driving along the two lane road on top can easily see the large blue metal and cement structure that controls the lake level.  When there is too much water, giant panels, or gates, control the lake’s level by releasing more into the Platte River.

Nate Nielsen is the foreman at Kingsley Dam on Lake McConaughy. (Photo: Bill Kelly/NET News)

On a recent visit with Nate Nielsen, the foreman of CPPD's Kingsley Dam, it was obvious the lake level was down, even after the winter season that can fill the massive lake with melted snow from western mountain ranges. 

Nielsen pointed towards the west side of the dam where piled rock was coated with a twenty foot wide stripe of white powder left behind by receding lake water.

“Lake McConaughy water has a lot of dissolved mineral in it and the white you see is a calcium build up on the rocks,” explained Nielsen. “That tells us that the water table has dropped a lot in the past year.  And it dropped all last summer.”

The very next day an April blizzard dropped a foot of snow across the Platte River basin that feeds water back to the lake.  More rain would drench the area later in the month.  It did little to raise the lake level. 

For the second year in a row mountain snow melt added below average supplies of fresh water to western streams.  The Platte saw only 70 percent of its average snow melt supply. 

Mineral deposits and painted markers reveal McConaughy's low level (Photo: Bill Kelly/NET News)

Glancing back at the tell-tale line of white along the shore, Nielsen predicted “we will double that” by the end of summer.  “We will be 15 to 20 feet lower than we are right now, he predicted. 

(Click here to check the daily update of McConaughy's water level)

 

While that sounds alarming, Lake McConaughy is only a barometer of drought conditions in certain ways for Nebraska.  “It’s a good indicator” said Don Kraus, CPPD's general manager , “but as far as irrigation across the state, it’s probably not as applicable.”

The Central Public Power District (CPPD) manages the lake and dam.  Kraus points about one million acres of Nebraska farm land is irrigated with surface water drawn from large and small reservoirs dotting the landscape.  The number of acres irrigated with groundwater pumped up from the below ground aquifer cover eight times that amount of land.    

Drought side effect:  Less Electricity

The low water levels are already affecting the other mission of CPPD.  Electric power generation has not been able to reach peak production with lake levels twenty feet below top capacity.  In the noisy room containing the generator, Ned Nielsen explain that the dam’s “maximum design capacity is fifty megawatts and we aren’t able to get to that right now because the water is so low.” Central sells electricity to supplement power generated by the coal and nuclear plants run by the Nebraska Public Power District.  While less can be generated when requested by NPPD, there’s no shortage of electricity.

Inside the Kingsley Dam generator room (Photo: Bill Kelly/NET News)

Even if McConaughy is low, “aquifer conditions are different,” said Kruse. “You can’t draw a direct correlation between the two, but it does indicate as you get the information on Lake McConaughy you can tell if you are in a drought cycle. 

Last fall Central Public Power anticipated another dry year. The board of directors cut back on the amount of water allotted to irrigation customers. There are about 110 thousand acres in south central Nebraska directly irrigated through this system.  Another 400 thousand acres get the benefits of additional water.  In a normal year CPPD hopes to supply irrigators with the same amount of water per acre a farmer would get from 18 inches of rain.  This year the allotment is only 10 inches per acre. 

Farmers relying on the irrigation system have already adjusted their plans for this year’s planting season.

“We’re just not going to plant as many crops on as many acres,” said Phil High, a corn and bean farmer near Bertrand, Nebraska.  “That doesn’t mean the end result won’t be the same.  We still have the ability to have just as many bushels.”

High says a profitable year is still possible because he was able to plan ahead based on getting the information about having less water for irrigation late last year.  By “being frugal” he adjusted how much seed was purchased and has a better idea of how much fertilizer may be needed in the coming weeks.

Irrigation system meter measures water delivered to CPPD customer (Photo: Bill Kelly/NET News)

The plan starts with “understanding this is going to be a water short year (so) our yield goals change,” said High  “Instead of thinking we’re going to raise 250 bushel corn, realistically, then maybe we’re going to shoot for 200, which is a very successful year, by the way.”

High farms some acres to the south, closer to the Nebraska-Kansas border using no irrigation.  That region has been especially hard hit by the drought for many more years.  While some of that land may not be planted at all this year on others he plan to plant more small grains or corn that matures more quickly so that it can be harvested earlier and needs less water. 

As the state watches the water level at Lake McConaughy level drop, High says “don’t panic.  At the end of the day, we’re a lot smarter than we were.  We do adapt.”

As climate swings have been more dramatic in recent years Nebraska producers have been demanding more information and analysis about water supplies.  Don Kraus of Central Public Power is hearing demands for data beyond his organizations traditional ‘one year at a time’ forecast. 

“Our producers are telling us you need to look a couple years out,” said Kraus.   “And so our folks are doing that.  As part of their planning they are saying ‘Okay, here’s what it might look like’ and it can be some pretty sobering graphs and statistics as you look at that.”

The other impact will be on the lake’s recreational users.  The wide sand beaches will return this year.  Some users consider that to be a benefit.  Many boaters don’t care for it since it makes use of access ramps difficult, if not impossible.

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