Record high water temperatures recorded in Niobrara River

Low water levels and hot weather contributed to the highest water temperatures ever recorded in the Niobrara River this summer.

On July 26, the U.S. Geological Survey measured the temperature in the Niobrara River, east of Valentine, at 92.7 degrees. That broke the record for the previous high of 90.1, recorded in 2017.

Matt Moser, a scientist with the U.S. Geological Survey, cautioned against blaming climate change, He said the U.S.G.S. has collected data in seven years beginning in 2014, but added “We don’t know what the temperature would have been in the other years we didn’t monitor.”

Instead, Moser pointed to more local factors, including low stream flow, as contributing to the record. Ordinarily, he said, the river flow is around 600 cubic feet per second at that time of year. This year, it was about about 520.

Kyle Temple, water resources coordinator for the Middle Republican Natural Resources District, said the amount of water used for both surface and groundwater irrigation has been about average this year.

But Temple said factors like the amount of rainfall feeding tributaries of the Niobrara, like the Snake River, could have a big effect on the flow.

And Temple pointed to other factors as well.

“One of the possible considerations, is just the perfect aligning of the stars of what is usual for the Niobrara: low flows in July and August… and high ambient temperatures in the late afternoon.

The National Weather Service recorded a high of 106 degrees on July 26 in the nearby city of Valentine, and 109 degrees the day before.

Moser said water temperatures can be critical for the health of fish and stream vegetation. And he said they could worry people who are canoeing and kayaking on the river to try and get away from the heat.

But he discounted any talk that the high temperatures portend some kind of ecological disaster.

“I would not say just based on the data we collected, there's any other concerns with the water that we have up there. Other streams within the state have exceeded that 93 degree temperature that we’ve monitored. So the Niobrara would not be unique that it’s experiencing those warm temperatures,” he said.