Dam Trouble

The worst one in U.S. history was the Jonestown disaster back in the 1800's. It was in Pennsylvania, about 2,200 died.

Water managers issued evacuation orders for nearly 200,000 Californians just hours before they thought an emergency spillway at Oroville dam could fail. Emergency officials said it would send a 30 foot wall of water downstream.

That might be hard to imagine, but a computer simulation by UC Santa Cruz research geophysicist Steven Ward shows flood waters would hit highway 70 in about 30 minutes. In less than three hours, it would hit Highway 99. After 9 hours, it would fan out to cover a 231-square mile area.

Ward says it would be a massive wave near Oroville. The videos of the main spillway releasing 100,000 cubic feet per second pale in comparison.

“We’ve seen all week the videos of the regular spillway operating at full speed at about 100,000 cubic feet per second. This partial break is about 20 times that. It’s going to overpower the dikes and levees for sure,” says Ward.

Freshly excavated hillside in 1968 showing the two main bedrock units, likely sheeted dikes(between blue lines) and the metavolcanics. Note the varying composition within the metavolcanics, light yellow-orange, dark orange, and very light grays, extending deep underground. Apparent dip to the layers is to the west. What are the circles on peoples heads?

..I'm figuring our how to retire and am failing miserably

In the face of overpopulation I wonder how
there can be increased wages.

Bill Croyle stood in front of an aerial photo of Lake Oroville and swept his hand across the top of the emergency spillway that was helping drain water out of the brimming reservoir. “Solid rock. All this is rock,” Croyle, acting director of the Department of Water Resources, said with an air of confidence at the Feb. 11 briefing.

Interviews and records suggest that the near-catastrophe grew out of fundamental problems with the original design of the emergency spillway that were never corrected despite questions about its adequacy.

The “solid” bedrock that Croyle thought would stand up to the force of the spill was soft and easily eroded. The long concrete lip of the spillway was not anchored into the rock. Critical power lines were strung across the spillway, which consists of nothing more than an earthen hillside covered with trees and brush.

“There is no way to rationalize running water down a hillslope with deep soils and a forest on it and weak bedrock,” said Jeffrey Mount, a UC Davis emeritus professor of geology and expert on California water.

Federal and state officials said the cause of the spillway’s near-failure was under investigation.