OROVILLE (AP) — Water will continue to flow over an emergency spillway at the nation’s tallest dam for another day or so, officials said Sunday.
Skies are clear, and the overflow is steadily slowing, California Department of Water Resources spokesman Eric See said. It’s expected to stop by midday Monday. Water began flowing over the emergency spillway at the Oroville Dam in Northern California on Saturday for the first time in its nearly 50-year history after heavy rainfall.
In addition to the emergency spillway, water also flowed through the main spillway that was significantly damaged from erosion. Officials said they’ll assess the damage starting Monday.
Unexpected erosion chewed through the main spillway earlier this week, sending chunks of concrete flying and creating a 200-foot-long, 30-foot-deep hole that continues growing. Engineers don’t know what caused the cave-in, but Chris Orrock, a spokesman for the state Department of Water Resources, said it appears the dam’s main spillway has stopped crumbling even though it’s being used for water releases.
“There’s been no additional erosion that they can see,” Orrock said.
Officials stressed the dam is structurally sound and there was no threat to the public. State officials also moved most of the millions of hatchery-raised fish imperiled by muddy water flowing downstream alongside the damaged spillway after sections of its concrete walls collapsed earlier this week, the department of water resources said.
About 150 miles northeast of San Francisco, Lake Oroville is one of California’s largest man-made lakes, and the 770-foot-tall Oroville Dam is the nation’s tallest. The lake is a central piece of California’s government-run water delivery network, supplying water for agriculture in the Central Valley and residents and businesses in Southern California.