Post date: Apr 17, 2014 1:37:58 AM

Lots of snow doesn’t mean big flows into Lake McConaughy

By LORI POTTER Hub Staff Writer | Posted: Tuesday, April 8, 2014 12:00 pm

HOLDREGE — Snowpacks in areas of the Rocky Mountains that provide runoff into the Platte Basin remain above 100 percent, but that doesn’t mean that Lake McConaughy will get a big “spill” of water this spring.

That’s because the large federal Bureau of Reclamation reservoirs upstream on the North Platte River in Wyoming, primarily Seminoe and Pathfinder, are at one-third of full capacity and can hold all the runoff from melting snow.

At Monday’s Central Nebraska Public Power and Irrigation District Board meeting in Holdrege, Civil Engineer Cory Steinke said the snowpack is at 126 percent of average in the upper part of the North Platte Basin, 130 percent in the lower part and 142 percent in the South Platte Basin in Colorado.

The good news is irrigation districts in the Nebraska Panhandle should have full water supplies this summer to create return flows that run down the North Platte River and into Lake McConaughy.

The lake now holds 1,067,000 acre-feet of water, including an environmental account managed by the U.S. Fish and Wildlife Service, which is about 61 percent of a full reservoir.

Steinke said inflows and outflows are about 1,000 cubic feet per second. The releases include 700 cfs from the environmental account.

USFWS officials started environmental account releases on March 29 and could continue them until May 10. The goal is to create flows of 1,700 cfs from Overton to Grand Island for roosting and feeding habitat used by migrating whooping cranes.

Steinke said no spills of excess water are expected in 2014 from the Wyoming reservoirs.

“I would expect if we see any water (in Nebraska) it will be in the South Platte,” he said, especially with uncertainty about makeshift structures built after last September’s flood in Colorado’s part of the basin washed out a number of small dams.

The timing for when and how fast the snow melts will be the key to whether Central can divert any excess flows in the South Platte River to fill irrigation canals and reduce releases from Lake McConaughy for that purpose. CNPPID Irrigation Division Manager Dave Ford said diversions will begin around April 15.

In other lake-related action, the Central board approved a request from Public Relations Adviser Tim Anderson for $100,000 over the next two to three years to help fund a meeting room addition to the Lake McConaughy Visitors Center.

Anderson said the Nebraska Game and Parks Commission and Keith County each have committed $100,000 to the project.

Much of Monday’s board meeting was spent answering questions from Central water user Gary Robison of Bertrand about the design and operation of the J-2 Reregulating Reservoirs that will be located between the Phelps Canal and Platte River in northwest Phelps County and northeast Gosper County.

Steinke said the reservoirs should have efficiency rates in the “high 90s” in returning temporarily held water to the river.

They will be nearly empty much of the time during day-to-day operations, he said, but could hold up to 25 feet of water when excess river flows are diverted and held for later release back to the river to meet USFWS targets.

Steinke and Natural Resources Manager Mike Drain said preliminary site studies done by consulting engineers hired by CNPPID show that clay suitable to line the reservoirs and other soils types needed for other parts of the project are available.

Steinke said a lot of dirt will have to be moved around at the site to get the clay and other soils separated for specific uses. “They’ll be doing a lot more borings,” he told Robison, but the $75 million cost estimate for the project is based on using local clay.

CNPPID will pay 5 percent of the cost, up to $2.5 million, with the Platte River Recovery Implementation Program paying 75 percent of the balance, and the state and natural resources districts paying 25 percent. Central’s main benefits will be the ability to run the J-2 hydropower plant at peak efficiency more often, while the Platte Program and state entities will get river credits at times when water held in the reservoirs is released to meet target flows.

In other business, the board:

- Approved a task order agreement with the Black & Veatch engineering firm for studies, not to exceed $150,000, to evaluate the potential costs and benefits of CNPPID joining the Southwest Power Pool.

- Approved a Hydro Division budget revision from $76,000 to $98,000 to reflect the cost of additional expenses to replace a pump in a collapsed E-65 well.

- Approved $5,000 for a Johnson Lake Development Inc. carp removal project.