LINCOLN, Neb.—The water level at the state’s largest playground and a major source of surface water irrigation is higher than it has been in five years and still rising.
Lake McConaughy is filled to 46 percent of capacity, according to Central Nebraska Public Power and Irrigation District, which owns Big Mac. That’s up from 39 percent last year and a steep increase from 2004. In September of that year the state’s largest reservoir was at less than 20 percent of capacity, its lowest level since being built in the 1940s.
“It’s a surprise,” Cory Steinke said of the lake level. He’s an engineer for the district. “The fact it’s coming up is pretty significant.”
Steinke pointed to good rainfall last year that reduced the need for Big Mac irrigation water in a wide swath of south-central Nebraska that is served by the district.
But the main reason may be strong flows in the South Platte River, which helped decrease releases from Big Mac, he said. The South Platte joins the North Platte River downstream of the reservoir.
And district officials also say the hard decision of reducing irrigation allocations is paying off. Farmers have been receiving less than 7 inches of water a year from the district, a sharp decrease from the 18 inches they normally get.
Though snowpack in the Wyoming mountains that melts and supplies the North Platte River was above normal this year, it could take three or four years of similar conditions to fill Big Mac. That’s because two key Wyoming reservoirs filled to around only 20 percent of capacity will suck up much of the water.
But water was recently released from two other Wyoming reservoirs that were filled after heavy rains, helping Big Mac.
Most of the water that fills Big Mac takes an indirect route from the Wyoming mountains in the form of “return flows”—groundwater that seeps into the river and irrigation runoff from Panhandle farm fields.
A full supply of North Platte irrigation water to the Panhandle reduces groundwater consumption and increases irrigation runoff into the river as it heads to Big Mac.
While they have mostly missed the heavy rain that has flooded other parts of the state, some portions of the Panhandle, including those adjacent to the North Platte, have gotten goodly amounts of rain so far this year.
There’s no need to irrigate yet, thanks to the cool and relatively wet weather, said Jason Post, a farmer and manager of the Crossroads Coop in Bridgeport, which is about 60 miles upstream of Big Mac. “There hasn’t been hardly any center pivot irrigation going.”
Nonetheless, climatologists consider the Panhandle abnormally dry and, in some areas, in a moderate drought, according to the most recent U.S. Drought Monitor. The rest of the state has emerged from the drought.
It will take more than a wet spring to cure Panhandle drought symptoms that have accumulated over several years, said state climatologist Al Dutcher.
“That drought is not going to change much,” Dutcher said. “Even with all the rain we’ve got … we still are significantly drier compared to where we should be.”
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On the Net:
Central Nebraska Public Power and Irrigation District:
U.S. Drought Monitor:
