HOLDREGE — Nebraska’s biggest lake will be getting bigger — or at least more full — during the next few weeks.
Lake McConaughy, on the North Platte River near Ogallala, held 1,534,300 acre-feet of water as of Monday morning. That is 88 percent of capacity and an elevation of 3,257.9 feet above sea level.
In his report at Monday’s Central Nebraska Public Power and Irrigation District board meeting in Holdrege, CNPPID civil engineer Tyler Thulin said Big Mac water releases of approximately 1,600 cubic feet per second compare to inflows that are averaging 2,900 cfs and are expected to continue rising for a few days.
Based on “a bunch of guessing by us,” Thulin said he and Hydraulic Projects Operations Manager Cory Steinke believe the lake will peak at an elevation “somewhere in the 3260s.”
“We don’t think we’re going to fill at this time,” Thulin added.
Additional inflows will come down the North Platte River from southeast Wyoming’s Glendo Reservoir.
Thulin said Glendo’s water is 30,000 a-f into its flood pool, so federal Bureau of Reclamation officials plan to release water when downstream river flows decline.
He said that while the snowpack in the Rocky Mountains above Glendo will be gone in the next week or two, snowmelt is starting now in the South Platte Basin.
“There’s a lot of snow left to melt in Colorado,” Thulin said. “... The later that snow hangs around, the faster it’s going to melt.”
High South Platte River flows allow CNPPID to use that water for hydropower production and irrigation rather than releasing stored water from Lake McConaughy.
Irrigation Operations Manager Dave Ford said the first irrigation run through CNPPID’s system is scheduled to start Monday.
When asked by the Hub whether the irrigation schedule will be followed, given the continuing wet weather in the main service areas in Gosper, Phelps and Kearney counties, Ford replied, “No. It’s not gonna happen.”
He said irrigation deliveries typically pick up around June 20. However, there may be some customers who need to run pivot irrigation systems earlier to soften the soil crust for emerging plants, activate herbicides or apply fertilizer.
In other water-related action, the CNPPID board approved two new five-year water service agreements — pending final legal review — with the Platte River Recovery Implementation Program that is comprised of Nebraska, Colorado, Wyoming and the U.S. Department of Interior.
The agreements also involve the Nebraska Community Foundation, which holds program funds.
The agreements set terms and PRRIP payments to Central to divert Platte water into the Phelps Canal and Elwood Reservoir at times when river flows exceed targets set by the U.S. Fish and Wildlife Service for habitat used by threatened and endangered species.
The diversions allow water to slowly recharge groundwater and eventually return to the river.
There is a 30,000 a-f annual diversion cap in the Elwood Reservoir agreement, but no cap on Phelps Canal diversions.
Steinke said the new agreements allow Central staff to alert Platte Program officials when excess river flows are available. “They can say ‘yes’ or ‘no,’” he said. “So we can act quickly.”
CNPPID Director Geoff Bogle of Elwood was concerned about the length of the new agreements. “You don’t know what will happen five years from now,” he said.
CNPPID General Manager Devin Brundage said it’s a natural progression to extend the life of agreements after projects such as the diversions have been in place for a few years.
Natural Resources and Compliance Manager Mike Drain said future agreements may require longer terms to give Platte Program officials planning certainty. Also, the revenues generated for CNPPID have been a plus for the district, he added.
“I think we’ve protected ourselves against every issue you’ve raised,” Steinke told Bogle. “... We do control the system.”
Steinke said there are times even in dry years when Platte flows exceed targets. CNPPID doesn’t have rights to use or store excess flows for its own use, so the water would flow out of the state if it can’t be used by another Nebraska entity.
There were 11 yes votes to approve the two Central-Platte Program agreements; Bogle abstained.