November 4, 2011

David Pearson, senior service hydrologist at the National Weather Service in Omaha, will present "The Missouri River Flood of 2011: Its Causes and Impacts" at a seminar Nov. 8 on UNL’s East Campus. His talk, which is sponsored by UNL's School of Natural Resources, will be at 7 p.m. in the Hardin Hall auditorium at 33rd and Holdrege streets.

"The driving force for this flood was heavy rainfall and above-normal snowpack in Montana and the surrounding mountains," Pearson said. "If you've got heavy precipitation at the beginning of the river, at no point can that water leave the system. It has to travel through every reservoir." He noted that without the control over river flow that the reservoirs provide, the Missouri River in Omaha would have been about four feet higher, which would have strained the capability of the city's levees.

Flood mitigation is one of several objectives in managing the river system, Pearson said. Other key considerations are hydropower, recreation, wildlife habitat, drinking water, and irrigation.

The National Weather Service provides forecasts of river levels to the general public and to the U.S. Army Corps of Engineers, which is the agency that oversees operations of the reservoirs and dams on the river system.

Although Pearson will discuss the flooding along the entire length of the Missouri, the bulk of his presentation will focus on events that occurred along the river between Gavin's Point Dam in northeast Nebraska, and Rulo in southeast Nebraska.

There was no way to prevent the flooding this year, Pearson said. Floods closed Interstate 29, washed away roads, inundated farmland, and triggered "unusual event" declarations at two nuclear power plants in Nebraska.

School of Natural Resources