A 250-foot long cavity opened in the Oroville Dam spillway yesterday as approximately 55,000 cubic feet per second was being released from Lake Oroville into the Feather River downstream.
DWR shut the spillway to investigate the rupture on February 7. The discovery of the giant hole caused a halt and reduction in water deliveries downriver.
The rupture takes place at a time when Governor Jerry Brown is promoting the construction of two massive Delta Tunnels and new water storage. Project critics say that the state should instead focus on maintaining and improving existing water system infrastructure, such as properly maintaining the spillway at Oroville, rather than focusing on environmentally destructive and enormously expensive tunnels and dams.
To help determine “an appropriate level of flow down the damaged spillway,” the California Department of Water Resources (DWR) plans to release up to 20,000 cubic feet per second (cfs) this afternoon, then ramp down the flows and assess any further damage to the eroded spillway, a news release DWR reported.
“The test flow will run for two hours, perhaps as soon as late this afternoon,” according to Ted Thomas, spokesman for the Department of Water Resources. “The test flow is expected to further erode the lower reach of the spillway, where a cavity opened yesterday as approximately 55,000 cfs was being released from the reservoir.”
“With the test flows, engineers will verify how much flow the spillway can handle. The spillway is necessary to maintain reservoir operations, given the immediate forecast of continued rain for the next two days and also in preparation for the remaining runoff season,” said Thomas.
“In the coming days, DWR will continue to investigate ways to bolster and protect the spillway. At the same time, as part of a contingency plan, the DWR is removing trees and debris from the corridor near the dam where water would flow in the event the emergency spillway is needed,” he said.
DWR said the emergency spillway, separate from the damaged spillway, is not gated, and water would flow naturally from the reservoir if it were to reach its capacity of 3.5 million acre feet at 901 feet elevation.
As of this afternoon, the reservoir holds 3 million acre-feet of water. Before the test flow, approximately 14,000 cfs were being released from the reservoir through other outlets, including the Hyatt Power Plant. The test will boost those flows temporarily to 34,000 cfs. Inflows to the reservoir are approximately 85,000 cfs, according to Thomas.
Thomas concluded, “Enough vacant space exists in the reservoir to capture the flow of the rains expected through Friday afternoon. The dam is sound, and no imminent threat to the public exists.”
DWR said it is coordinating closely with State and federal wildlife and dam safety officials as it responds to the spillway erosion. Lake conditions, including lake levels, inflows, and outflows can be obtained via a recorded message at 530-534-2307.
Critics of the Delta Tunnels project said the Oroville Dam spillway rupture shows how basic dam assessments, management plans, and maintenance are being neglected as Governor Jerry Brown constantly promotes the California WaterFix as the “solution” to the state’s water supply and ecosystem problems.
“According to the American Society of Engineers 2013 Report, there are 678 high hazard dams in California, and 48% of them do not have an emergency plan,” said Barbara Barrigan-Parrilla, executive director of Restore the Delta, responding to the Oroville Dam rupture. “Watching the damage unfold at Oroville, it is striking to us that Governor Brown, CA WaterFix proponents, and Department of Water Resources leaders keep telling Californians that the tunnels are the needed fix for updating California’s water delivery system, yet basic dam assessments, management plans, and maintenance are forgotten or put off.
“The Federal Government had indicated that Oroville Dam needed a further seismic assessment, but the Department of Water Resources stated in 2013 that a seismic assessment of Oroville Dam was not needed. What would happen if an earthquake were to happen near the dam today during this high water event?” she pointed out.
“While an emergency plan for Oroville Dam exists, it is clear that something is lacking in maintenance and planning that such a large hole has opened up in the spillway. Clearly, the Department of Water Resources is not prepared to manage the system during wet years,” she said.
“The Governor and DWR officials want to spend $60 billion, on unnecessary Delta tunnels, a wasteful expansion of infrastructure that will not address California’s dated water delivery system. What we need is a major investment in upgrading our 678 high hazard dams, and making sure that dams like Oroville can stand up without ruptures during high water years. We need to upgrade and maintain the infrastructure that we have first to protect people and ensure water deliveries. If the tunnels are built, there will be no additional cash from state and local agencies to pay for needed dam maintenance, and locally needed water system upgrades,” Barrigan-Parrilla concluded.
On February 6, twelve public interest groups, led by Consumer Watchdog and Food & Water Watch and including Restore the the Delta, challenged Governor Jerry Brown’s green credentials at a press conference in Santa Monica. The groups unveiled a comprehensive report card on Jerry Brown Administration’s environmental record showing he falls short in six out of seven key areas, including fossil fuel generated electricity, oil drilling, and coastal protection.
The report calls for a moratorium on the building of natural gas powered electricity plants, given what they described as “the glut of electric capacity” and calls for an outside audit of state’s energy needs. The group showed how California can improve its environmental protections to meet standards set in other states.
The report, noting that Brown’s infrastructure projects, led by the California WaterFix, “deplete water resources and threaten wildlife,” also urges the Governor to abandon the Twin Tunnels project.
Read the report “How Green Is Jerry Brown” at: http://www.consumerwatchdog.org/isbrowngreen