Slashdot Mirror
188,000 Evacuated As California's Massive Oroville Dam Threatens Catastrophic Floods (washingtonpost.com)
Mr D from 63 quotes a report from The Washington Post: About 188,000 residents near Oroville, Calif., were ordered to evacuate Sunday after a hole in an emergency spillway in the Oroville Dam threatened to flood the surrounding area. Thousands clogged highways leading out of the area headed south, north and west, and arteries major and minor remained jammed as midnight approached on the West Coast -- though by early Monday, Lake Oroville's water level had dropped to a point at which water was no longer spilling over. The lake level reached its peak of 902.59 feet at about 3 a.m. Sunday and dropped to 898 feet by 4 a.m. Monday, according to the Sacramento Bee. Water flows over the emergency spillway at 901 feet. "The drop in the lake level was early evidence that the Department of Water Resources' desperate attempt to prevent a catastrophic failure of the dam's emergency spillway appeared to be paying dividends," the Bee reported Monday. Officials doubled the flow of water out of the nearly mile-long primary spillway to 100,000 cubic feet per second. The normal flow is about half as much, but increased flows are common at this time of year, during peak rain season, officials said. But water officials warned that damaged infrastructure could create further dangers as storms approach in the week ahead, and it remained unclear when residents might be able to return to their homes.
Question: Which energy technology has displaced the most people from their homes and villages, has rendered the most land uninhabitable by humans as well as all native plants and animals, and has killed thousands of square miles of animal and plant life?
Answer: Hydro of course. Everyone's favorite renewable. The source so many countries credit for high renewable percentages.
Other interestig tidbits: Deforestation due to hydro results is reduced carbon sequestration. Also, decay of plant material under hyrdo reseviors and active aquatic microbial digestion is a source of added methane emmissions. Studies show these emissions may be quite high.
I think Hyrdo is a great power source. But nothing comes without trade-offs. I think most here are willing to trade off the things I listed above for the benefits of hydro.
This dam is primarily for water supply, the hydroelectric aspect is secondary.
I just wanted to post some info before everyone spins this as a partisan failure of one sort or another.
1) The dam was built and is owned by California.
2) California was warned about the potential problem (the one we are currently seeing) in 2005.
3) In 2005, as part of the federal re-licensing procedure for the dam, several groups urged federal officials to require that the dam’s [earthwork] emergency spillway be upgraded to concrete. The federal government declined.
4) The dam was built at a time when requirements were less strict in comparison to today's standards. The dam foundations were dug down to "weathered" rock, which is less structurally sound than "bedrock".
And finally,
5) As much as people feel the need for karma or justice or revenge or whatever, we DO NOT punish people's lives and homes over partisan bullshit. The federal government should (and most probably will) assist in any way that they can to help avoid a disaster.
As has been pointed out by many people, California spent several billions of dollars on the hyperloop while letting this particular bit of infrastructure upgrade get ignored. Both California and the Federal government (viz: the licensing mentioned above) can share the blame for this.
It's another Katrina-like situation: both governments (Cali and Federal) were warned, did nothing, and now it's an emergency.
Also of note, and I'm trying to look at the big picture here and not point fingers, it's been pointed out that the infrastructure in our country has been neglected for a long time (especially roads, bridges, and the electrical grid), and we really need to start fixing up things.
Fixing our infrastructure was one of the campaign promises of the party in power, perhaps this will galvanize them to action.
First, Oroville, California, gets 52 inches of rain per year. NOT a desert.
According to US climate data 30.7 inches of precipitation per year
http://www.usclimatedata.com/c...
which is about 20% less than the national average
https://rainfall.weatherdb.com...
Still: not a desert.
http://www.geoffreylandis.com
3 Groups filed briefs as far back as 2005 requesting that California update the overflow spillway as part of the re certification process. The overflow was found not to meet standards and caused risk. California put 0 money into the issue and ignored it. But hey, we got more welfare and crony projects like the Bullet-CrazyTrain. http://abc7news.com/news/repor...
-The wise argue that there are few absolutes, the fool argues that there are no probabilities.
This isn't something specific to California. There's old infrastructure that's been poorly maintained all across the country, mostly because no one has been willing to put up the money to pay for it, here, there, or anywhere. Here's a report on that from last year, though it was sparked by failures of dams elsewhere: http://www.npr.org/2015/10/11/...
Second - yes, this is a 'natural disaster', because that's exactly the term we use when the natural phenomena dump ridiculous amounts of water in a particular location. In other places it produces devastating floods, like last year in South Carolina. Here California was somewhat lucky, because they had a dam like this in place with an empty resevoir that absorbed it - and that wall of water would otherwise be flooding the valley below, along with all the people who live there, and may yet still if the emergency spillway collapses.
There's actually 2 things going on.
The existing spillway is made of concrete, and suffered some structural damage.
Here is an image of the damage, from a couple of days ago, and here is that same spillway today.
The lower half of the spillway is probably completely gone. The raging water might erode up to the level of the dam, but that's not likely.
The actual problem was the emergency spillway, which is an earthen bank to the left (looking up to the dam) of the regular spillway.
You can see the damage in this image. Note that one of the eroded canyons reaches almost up to the level of the water.
If the erosion had reached the emergency spillway it would have burst, releasing a whole lot of water downstream.
Here's a closeup, and note the middle lower portion of the image. We were that close to a breech.
That didn't happen, and the waters are now below emergency levels.
However, the situation is rather precarious and the emergency spillway could still burst. There's still a lot of water still coming in to the reservoir, which is being frantically lowered.
(And yes, I wrote "Hyperloop" when I meant "High Speed Rail" above.)