The Oroville dam has largely faded out of the news in the past few weeks but the crisis is not over yet. A report on the safety of the dam concluded: “A very significant risk would be incurred if the Gated Spillway is not operational by November 1.” November 1 is the start of the next rainy season. From the Associated Press:
Officials with the state Department of Water Resources, which operates the dam, fear a huge rupture that opened in the main spillway could expand to cripple the flood gates that send out controlled releases of water and keep water from spilling over uncontrollably.
In a statement, spokeswoman Maggie Macias said the agency’s objective is to have a fully functional spillway before the start of the next storm season.
“We’ll be working round-the-clock through spring, summer and fall to make that happen,” she said.
In case you’ve forgotten what the main spillway looks like, here it is:
Note the size of the helicopter in this image for scale:
So California has about 7 months to shore up all of this damage and repair the spillway in time for the next rainy season. And there is concern that repairing the visible damage will not be enough. Inspectors found water was leaking between the apparently undamaged sections of concrete, meaning even the sections of the spillway that look salvageable may need to be replaced or repaired before it can be used safely. The cost to repair all of this damage is expected to be in the tens of millions of dollars.
The report also says the emergency spillway should not be used under any circumstance and needs to be redesigned. If you recall, authorities briefly allowed water to flow over the emergency spillway last month and then saw evidence the ground below it was in danger of undermining the concrete. Though the Oroville dam itself was never in danger, 188,000 people were evacuated over concern the spillway could fail catastrophically, sending a wall of water into downstream cities and towns.