Engineers hope to begin repairs as soon as possible on a crumbling emergency spillway on the US’s tallest dam in northern California. They have so far managed to drain off some excess water from the rain swollen Oroville lake, easing the threat of flooding to communities down stream.
OES (@Cal_OES) February 13, 2017
Nearly 200,000 residents were earlier evacuated when one of two damaged spillways appeared in danger of collapse.
Butte County Sheriff, Kory Honea said people will be able to return to the their homes as soon as it was deemed safe:
“Getting those people home is important to me. I want that to happen as absolutely soon as possible. But I have to be able to sleep at night knowing that they’re back into that area. And if it’s raining and there’s more water coming in the lake, if I can’t in good conscience believe that those people are safe, I haven’t done my job.”
The damage to the main spillway – a concrete-lined chute running adjacent to the eroding hillside spillway – has been caused by weeks of heavy rain in a state that has endured five years of drought.
The authorities insist the structural integrity of the dam itself remains sound, but a broken spillway has the potential to release a cascade of water three stories high downstream.
For now the priority is to lower the overall water level in the reservoir by 15 metres before more rain arrives this week.
The crisis at Oroville Dam is a reminder of the shoddy shape of America's dam infrastructure: https://t.co/laCojmRUHC— Ezra Klein (@ezraklein) February 13, 2017