Posted on 02/25/2020 5:30:49 PM PST by BenLurkin
Worried that an earthquake could collapse a big dam south of San Francisco, officials have ordered its reservoir to be completely drained by October to reduce the risk of floodwaters spilling into Silicon Valley.
The 240-foot (73-meter) high earthen Anderson Dam, built in 1950 between San Jose and the community of Morgan Hill, poses too great a risk of collapse and must be fully drained by Oct. 1, according to the Federal Energy Regulatory Commission, which regulates dams, the Mercury News reported.
Since 2009, the dam’s water level has been kept at a maximum of 74 percent of capacity because of an assessment that it could fail in a 7.2 quake. The reservoir is built along the Calaveras Fault. On Monday, amid the threat of another drought in California, Anderson Reservoir was just 29% full.
A seismic retrofit project has been underway because of its state classification in 2017 as being an “extremely high” downstream hazard.
The Santa Clara Valley Water District said in a statement Monday that officials agree with the commission’s assessment that the reservoir should be drained ahead of the retrofit project, which is “complicated and time consuming.”
More than 14,000 residents had to be evacuated in 2017 as water from swollen Coyote Creek, downstream of the Anderson Reservoir, flooded homes and temporarily shut down a portion of a freeway.
It came the same month as a spillway failed at the nation’s tallest dam, in Oroville in Northern California, leading officials to order the evacuation of nearly 200,000 people.
Stored water is an important part of the south San Francisco Bay Area’s supply — with enough water for the annual needs of at least 130,000 people as well as what the district considers an emergency supply
(Excerpt) Read more at ktla.com ...
Yeah, a hundred years ago.
Shasta can be safely raised.
“Hasn’t happened yet.”
Northern bridge on I-5 across Lake Shasta has been raised.
It's working in China.
built in 1950 between San Jose and the community of Morgan Hill,”
The area would have been very rural in 1950. Not much worry about houses and people below it then.
Much different now.
Dams are a real hazard in earthquakes. The last thing you need when you have an earthquake, fires, blocked roads, and the rest of the mess from a big one is to also have flooding.
Anderson Dam has been an issue for 40 years. Sometimes a cigar is just a cigar.
Of course if people/planners were smart, they wouldn’t build in a flood plain. I know, not always possible, but still...
It’s different in California. It’s not really a floodplain until they put the dam there. There isn’t normally enough water even in a heavy rain to flood those areas - except when a reservoir collapses.
I lived in the South bay area for 20 years. The Morgan Hill area and the valley along Coyote Creek between Gilroy and San Jose is a flood plain. It is a 50 year flood plain if I recall, but a flood plain none-the-less. CA has mismanaged everything. They dont allow new home construction in the mountains east of Coyote Valley, but they allow any and all construction in the valley along the creek. Build on farmland, but don’t build on state (Don) owned wilderness. Idiots.
Okay, thank you.
It’s a good thing that San FranSicko doesn’t allow street and sidewalk cleaning to eliminate the heaps of festering human excrement because it’s racist to do so. As a result, they need much less water.
I might have jumped the gun on that one, if in fact the dam is being drained in compliance with what President Trump wants.
But I will not lower my vigilance against the deep state.
You have that much faith in California government?
A dam on or near an earthquake fault line is not a good idea.
NONE WHATSOEVER.
ZERO.
My faith in government extends to a belief that it will do everything it can to destroy useful California citizens and replace them with malleable serfs.
I guess that’s my point. Yes, Shasta can be safely raised. But will California raise Shasta safely? I doubt it.
The Oroville spillway repair went reasonably well.
I was involved in that.
Shasta should be raised. It can be done - even allowing for CA shenanigans...
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