Some cooler, wet weather and a maturing corn crop have allowed a reduction in outflows from Nebraska’s largest reservoir, which is more than 30% below last year's capacity.
At the Central Nebraska Public Power and Irrigation District’s monthly board meeting, Civil Engineer Cory Steinke said weather and reduced demand for irrigation allowed them to reduce outflows from Lake McConaughy by about 1,400 cubic feet per second last week. Releases have been averaging about 3,400 cubic feet per second per day, while average inflows to the reservoir have been about 360 cubic feet per second over the past month.
Steinke says inflows to Lake McConaughy, which are categorized as natural flow in the river during irrigation season, have been well below normal for the entire summer. Lacking sufficient natural flow to meet downstream irrigation needs, the demand for storage water from the reservoir has been high. Because Central’s natural flow appropriations are junior to every other canal on the North Platte and Platte Rivers, Central’s irrigation customers primarily receive storage water from the reservoir. Only on rare occasions, according to Steinke, such as last year, is natural flow sufficient to meet most irrigation demands. Lake McConaughy also provides supplemental storage water to several other canals that lack storage facilities.
Lake McConaughy’s elevation as of yesterday was 3239.2 feet above sea level, which is about 61.5 percent capacity. That’s compared to 62.9 percent capacity a week ago, 71.4 percent capacity a month ago, and 96 percent capacity a year ago.
Flows in the Platte River, fed primarily by snowmelt from the Rocky Mountains in Colorado and Wyoming, underwent a dramatic reversal from last year when reservoirs from Wyoming to McConaughy were spilling excess water. Mountain snowpack is well below normal this year and the river has show the effects of a drought categorized as “extreme” by the National Drought Mitigation Center at the University of Nebraska-Lincoln.
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