KEARNEY, Neb. — Platte River floodwaters have been diverted by the Central Nebraska Public Power and Irrigation District since the high flows reached North Platte on Friday evening.
Now, Johnson Lake residents will start seeing a quick rise in lake levels.
Cory Steinke, a civil engineer with the district, said he's diverting the maximum possible, 2,250 cubic feet per second, into irrigation canals and reservoirs.
He said the high flows were at North Platte by 9 p.m. Friday, and he had opened the gates to reach that maximum by midnight. “We went from 1,500 to 2,200 cfs in no time. We were spilling water by the second hour,” Steinke said.
Water went into the Phelps and E-65 canals and was being pumped into Elwood Reservoir on Friday night.
Steinke said he drew down Johnson Lake a bit over the past couple of days to make more room for the diverted floodwaters. “I'm trying to take the peak off the flood,” he said.
He also has been running about 1,000 cfs through the J-2 Hydro and then returning 800 cfs to the river. That will change now that the floodwaters have reached Dawson County.
Steinke plans to reduce flows through the hydro and start filling Johnson Lake faster in the next 24 hours.
Staff at the National Audubon Society's Rowe Sanctuary along Elm Island Road southwest of Gibbon also are paying close attention to the flood's progress and flows.
“No, we're not worried about this amount of water,” Rowe Director Bill Taddicken said when asked if any flood precautions were being taken.
He explained that Audubon staff have worked for the past 40 years to widen the river channel and keep sandbars clear of vegetation along the Rowe property. That 800- to 900-foot-wide open channel can carry a lot of water, he said, because it can spread out and flow unimpeded.
“So managing the river for cranes helps humans, too,” Taddicken said.
He's more concerned about the effects of man-made structures, particularly bridges that aren't engineered to withstand floods. “There's a choke point at each bridge,” Taddicken said, because water must flow through an area only 80 to 100 feet wide.
Flows of 12,500 cubic feet per second now forecast at Kearney by the National Weather Service office in Hastings are much lower than some peak flows recorded over the past 30 years.
Taddicken said flows of 9,800 to 10,000 cfs were common throughout a wet 2011. He checked records that included peaks of 23,700 cfs in 1983, 16,100 cfs in 1984, 19,200 cfs in 1995 and 13,400 cfs in 2008.
Taddicken said people can watch the river rise over the next few days from the crane cam Rowe Sanctuary has set up overlooking the river.