Two new lakes will be created in the Platte Valley near the river, between Overton and Lexington, under an agreement between conservation and irrigation groups.The lakes will be used to storing excess water that can be released into the river when the river gets too low. They will be shallow, and located on the Phelps County Canal south of the Platte River, said Jeff Buettner, CNPPID spokesman.
The cost to construct the facilities, including improvements to the Phelps Canal, is estimated at $75 million, Buettner said. It is anticipated that the reservoirs could be in operation by late 2015 or early 2016.
Central's board approved the agreement on an 8-2 vote with one abstention and one director absent.
The next steps in the project include final project design, acquiring state and federal permits and starting negotiations for land acquisition, Buettner said.
The lakes would be known as the J-2 Regulating Reservoirs because of their nearness to Central's J-2 hydroplant and the J-2 river return below Johnson Lake, the reservoirs will have a surface area of about 1,000 acres (less than 2 square miles) and a capacity to hold about 15,000 acre-feet of water.
Buettner said the reservoirs will re-time returns of water from Central's public power and irrigation system to help offset shortages to U.S. Fish and Wildlife Service target flows in the Platte River and help threatened and endangered species habitat along the river.
He said the reservoirs are expected to yield about 40,000 acre-feet a year through retiming and will also be used to enhance periodic short-duration, high-flow events to help maintain the river's braided characteristic.
Additionally, Central will be able to use the reservoirs to increase generation efficiency at its J-2 hydropower plant while limiting impacts to irrigation operations and river flows.
The program will be assigned 75 percent of the yield from the operation of the reservoirs to offset shortages to target flows, while the state of Nebraska will be credited with 25 percent of the yield to help offset depletions to the river.
The agreement includes Central, the Platte River Program through the Nebraska Community Foundation, and the state of Nebraska through the Department of Natural Resources.
The Platte River Recovery Implementation Program will provide most of the funding for the project while the DNR will provide approximately 25 percent of the costs associated with the construction. Central's share of construction costs will be capped at $2.5 million.
Since the project is closely tied to Central's hydro-irrigation system, Central will own and operate the reservoirs.
Also, civil engineer Cory Steinke reported that Lake McConaughy's elevation as of July 1 was 59 percent of capacity.
Water from the big lake is now being released for irrigation, while inflows into the lake have fallen to about 30 percent of normal for this time of year.