The gauge had been ripped away by the wall of water released when the 90-year-old Spencer Dam failed under the pressure of the river, swollen with rain and rapid snowmelt and broken ice. But its last readings allowed Lambrecht to measure the size of the surge.
Earlier, the Niobrara had been running at 5 or 6 feet of gauge height. After it broke through the dam, it measured nearly 17.5 feet. It wasn’t a gradual increase, either.
“It started a really fast rise,” he said. “There was an 11-foot wave that rolled through.”...