A map intended for planners and first responders plots the likely path of devastation should either of the compromised spillways at Lake Oroville fail while the reservoir is full.
The scenario nearly occurred six and a half weeks ago, forcing the sudden evacuation of about 180,000 people. Residents were given an hour’s notice to clear out.
The new map was prepared by the Department of Civil and Environmental Engineering at UC Irvine. It is based on data collected for an official federal flood resiliency effort.
Adam Luke, a UC Irvine graduate student, is working toward a PhD in civil engineering.
“We can actually show areas where, which are likely to experience floodwaters strong enough to move cars, damage homes and even completely remove homes from their foundations,” Luke said.
Shortly after the height of the emergency, Officials stated a 30-foot wall of water would tumble toward Oroville if either spillway failed.
Based on that figure, the UC Irvine model envisions more than 450,000 acre feet of water cascading into the valley — that’s about 13 percent of the reservoir’s capacity.
Water would sweep into downtown Oroville about half an hour after a breach. Highways 70 and 162, main routes used during last month’s evacuation, would be enveloped by water moving with enough force to wash away homes. Lincoln Boulevard would be one of the few safe routes out. The historic downtown would likely be scoured away.
Further south, flooding would be minimal in Biggs and Gridley, but more serious in Live Oak. While further away, Yuba City and Marysville could see worse damage if local levees were overtopped or undermined, which researchers expect. Flooding would reach nearly to Sacramento International Airport. Luke said the map could help officials guide future development.
“You can severely reduce losses in flooding events with some type of coherent preparedness and response plans in place,” Luke said.
The National Science Foundation, which funded the research, is expected to face a significant reduction in funding under the president’s budget blueprint.