The Whole DAM situation (Tallest dam in US), deteriorating spillway causes lots of anxietyby HypostaticUnion
http://imgur.com/gallery/xHfxx(Go to link for click-zoomable full-size pix.)
This is Oroville Dam (right) and the spillway (left). Oroville Dam is the tallest dam in the United States, 50 ft taller than Hoover. It is in Northern California in a little town called Oroville (go figure). 1 hour north of Sacramento, close to Chico, CA, 2 hours south of Redding.
During these storms, the spillway was releasing 70,000 cfs of water (cubic feet a second). Large chunks of concrete began shooting off the spillway. Water started shooting into the air at this sink hole spot.
After shutting it off, they discovered this HUGE sink hole. Speculation now is that during the years of drought, the ground pulled away from the concrete. State experts are working on the cause, but we still have BIG problems.
Just some banana dudes for scale. The lake is rising during the current storms at a rate of about 130,000 cfs. It is almost near capacity. They need to release water so the dam doesn't crest or the emergency spillway be used.
Overnight they did some water releasing tests. Bigger hole. Every goes into emergency meetings. Huge hole + powerful water = no easy solutions. Lake is still rising. Town is getting very scared. Many remember the evacuations during the 96-97 El Niño season.
A little side by side. Remember the dudes.
There is an emergency spillway but the State doesn't want to use it for a couple reasons. (1) They never have used it. (2) The water just spills over the the wall down the mountain. Lots of debris into the river could clog downriver smaller dams. (3) There is not controlling this. It is an open system, kind of like that little hole in your bathroom sink. The rate the water goes into the lake would be the rate the water goes over the emergency spillway. It could reach 200,000 cfs if it keeps raining.
THEY HAVE A PLAN - and that plan is just to use the busted up spillway at a limited capacity. This will make the concrete problem a lot worse, but will hopefully help them beat the rain. Lots of repairs late spring and early summer. As you can see, the water is rushing down side, eroding the hillside. This is about 20,000 cfs.
Here it is at about 40,000 cfs. They turned it up because it rained hard. They are seriously trying not to use the emergency spillway, but they are clearing trees now because it looks like it might be used for the first time sometime Saturday.
Memes are cropping up.
Here is my contribution.
Thank you for following our journey. The Officials say there is no imminent threat to the public. Evacuations haven't been scheduled, but all the schools are closed (for some reason). The DAM is totally fine, for now, but our town is on edge because of the weird stuff with the spillway. It has been a total paradigm shift, all of us realizing we live downstream from a potentially huge issue.
Edit by Mod1 to merge two threads and add updated information about evacuation
