You guys suck at sarcasm. I understand it; I just think it's funny that they have you park in an area that is used in an emergency. It's not the same, but 'funny,' in the same way if the parking lot were also a Helipad for life flight.
Light to moderate rain began falling across Northern California early Thursday and will likely continue for several days, according to the National Weather Service.
However, the situation will change substantially Sunday when a larger storm arrives at Oroville and the Feather River basin.
“It looks like it’s going to be a pretty good rainmaker,” said NWS meteorologist Mike Smith. “You’re looking at 10 inches from Sunday night to Monday night.”
Overall, forecasters have predicted a series of four storms, with the first arriving Thursday, the second arriving Saturday, the third on Sunday night and the fourth on Wednesday of next week.
The largest of that train of storms will be the one arriving Sunday night. Much of the water falling across the local mountains and foothills is expected to flow directly into the reservoir. This comes at a time when Lake Oroville is at 88% of capacity and the ground and surrounding foothills are saturated from one of the wettest winters on record.
The Department of Water Resources hopes to drain up to a third of the lake to make room for rain and snowmelt and has been sending water down its damaged main spillway and into the Feather River at a rate of 100,000 cubic feet per second.
"Forecast confidence is increasing that this early next week storm could be the warmest, wettest and pack the strongest winds on this series of storms," states a briefing memo from the National Weather Service.
Warm is not good because it means the rain could also melt snow stockpiled in the basin.
So new for cast is light rain till Sunday then 10 inches Sunday Night thru Monday night...
Source?
Edit: ah I see, wasn't getting those numbers here but downstream so I don't get the same level of accuracy for that area. Also sounds like they revised it recently. Fun times...
Thanks to @Mayabird for pointing this thread out to me. The San Jose Mercury News has an interesting article on the cause of the spillway collapse.
In short, this damage is caused by cavitation, which is also how pistol and mantis shrimp hunt their prey. Basically, as millions of gallons of water rush over the concrete spillway, tiny cavitation bubbles are formed on the surface of the concrete due to the rapid changes in pressure cause by such amounts of water moving at such speed. As the bubbles collapse, they release energy that over time damages the structure, eventually resulting in the collapse seen above.
Interestingly, arreration gates can be installed to avoid this exact scenario, as was done in the 80s following similar problems at the Glen Canyon Dam in Arizona and subsequently Hoover and Blue Mesa dams, however this particular dam in Oroville never received the upgrades. They're now looking at repair costs in the billions while the preemptive fix of installing arreration gates would have cost only a few million.
"If complete and utter chaos was lightning, then he'd be the sort to stand on a hilltop in a thunderstorm wearing wet copper armour and shouting 'All gods are bastards'."
Thanks to @Mayabird for pointing this thread out to me. The San Jose Mercury News has an interesting article on the cause of the spillway collapse.
In short, this damage is caused by cavitation, which is also how pistol and mantis shrimp hunt their prey. Basically, as millions of gallons of water rush over the concrete spillway, tiny cavitation bubbles are formed on the surface of the concrete due to the rapid changes in pressure cause by such amounts of water moving at such speed. As the bubbles collapse, they release energy that over time damages the structure, eventually resulting in the collapse seen above.
Interestingly, arreration gates can be installed to avoid this exact scenario, as was done in the 80s following similar problems at the Glen Canyon Dam in Arizona and subsequently Hoover and Blue Mesa dams, however this particular dam in Oroville never received the upgrades. They're now looking at repair costs in the billions while the preemptive fix of installing arreration gates would have cost only a few million.
I know the practical effects of it are shitty and dangerous, but the mechanic of it is actually really neat and something I would have in no way thought of.
So Monday evening will definitely be the time to keep an eye out on the dam - if we can make it through Tuesday, I think we should be out of the woods.
Thank Goodness It's Bedrock should be printed in 100 foot tall letters and placed over the top of the spillway gates if the dam makes it through this.
+6
jungleroomxIt's never too many graves, it's always not enough shovelsRegistered Userregular
Pulling for all of you westies.
I was concerned your drought was gonna break in this fashion. I really was hoping for a nice extended minor deluge that the ground could've kept up with.
Glad to see things are looking a bit more under control.
Thank Goodness It's Bedrock should be printed in 100 foot tall letters and placed over the top of the spillway gates if the dam makes it through this.
and in 1000 foot tall letter above that it should read "HEY MAYBE WE SHOULD ACTUALLY FUCKING SPEND MONEY ON INFRASTRUCTURE"
I mean, yes, but that's not really what happened here. They could have put in the aeration gates, but I don't know that California has done many of those. The federal dams have, but it seems to be mostly for the flood control dams that use the spillway much more often.
Just so I've got this straight, California went from totally drought ridden, trying to figure out how to protect what little water they have, to completely over stocked with water to a destructive degree?
It's just how we roll. Last year we were having floods and wildfires at the same time. Nbd.
Just so I've got this straight, California went from totally drought ridden, trying to figure out how to protect what little water they have, to completely over stocked with water to a destructive degree?
It's just how we roll. Last year we were having floods and wildfires at the same time. Nbd.
Somewhere in my possessions I have a picture from my youth growing up in West Palm, which is of a "Danger: Extreme Drought. Do not dispose of cigarette butts" sign that was posted in the drainage ditch along the highway. Everything but "Danger: Extreme Drought" was under about 3 and a half feet of water from a week of insane thunderstorms.
They dropped it 50 feet since the crisis, so they have a decent amount of a storage. They've dropped the outflow from 100k cfs to 60k since then, looks like it's only recently exceeding that in inflow (90k cfs or so)
At least in our area, it seemed like less rain had come down than was anticipated. But I know Salinas, where my family lives, has had significant multi-day power outages and some mandatory evacuations, a few roads have succumbed to mudslides, and the river is a few inches away from overflowing. Soooooo.
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+1
OrcaAlso known as EspressosaurusWrexRegistered Userregular
Hah. I wonder if they ever upgraded that bridge on Trabuco Canyon Road. If not, I bet that thing got overtopped yet again...
Tuesday morning at around at about 6:30 a.m., San Jose Fire received reports of people in trees near Lone Bluff Way and the Los Lagos Golf Course. Over the course of the next few hours, fir boat crews pulled five people from the flooded homeless encampment.
Then fire crews were faced with evacuating dozens of homes and businesses in the Nordale neighborhood near Kelley Park, according to San Jose fire spokesman Capt. Mitch Matlow.
“Coyote Creek is rising because of water coming out of Anderson (Reservoir),” Matlow said. “We have a neighborhood that’s basically underwater.”
The crews responded to the Nordale area at about 10 a.m. just after completing the rescue operation at the Los Lagos Golf Course and as the high waters continue to flood downstream towards the Bay, more neighborhoods could be inundated.
Water rescue teams were using boats and other vehicles to go door-to-door and pull residents to safety, Matlow said.
City officials have declared a local emergency and issued a call for voluntary evacuations of neighborhoods along the creek, which traverses the length of the city from Morgan Hill to the San Francisco Bay.
friend in hollister had a real scare yesterday. Water pretty much surrounded everything thankfully their barns and house were good but their road was impassable and most of their neighbors got flooded out. Problem is right now all the rivers/creeks are running full bore so if any big rain hits they are starting to get dangerous flash flooding now as the rivers/streams can't hold any more without spilling over.
Dunno. Storm that hasn't hit yet was expected to fuck the Bay Area and the Central Coast pretty bad but it looks like it's calmed down. Looking at the storm system it didn't look like it was really hitting further North.
Vis a vis repairs: there isn't going to be much of a dry season. Runoff will continue through probably July this year, then a break until maybe oct/nov when storms usually start up.
The other thing that hasn't been mentioned here, iirc, is that there is a power plant at the base of the dam. It has been damaged during this incident, but when it's repaired and running it can pass up to 13000 or so cfs by itself, and draw much lower than the spillway.
So first order of business is fix the power plant, switch to using that instead of the spillway, then evaluate the main spillway.
To buy time for repairs to the main spillway theyll have to draw down and hope there's no major inflows during construction.
Repairs to the auxiliary spillway are ongoing and will continue.
+2
TL DRNot at all confident in his reflexive opinions of thingsRegistered Userregular
Isn't 13k CFS relatively low compared to the capacity of the spillway?
0
OrcaAlso known as EspressosaurusWrexRegistered Userregular
Isn't 13k CFS relatively low compared to the capacity of the spillway?
Yes.
The spillway a week ago was running at 100K CFS, and has a maximum design capacity of 150K CFS according to the California Department of Water Resources FERC document. Apparently the Feather River hit a maximum flow of 290K CFS in March 1907, by the by (page 50). That same document at page 59 describes the emergency spillway as having a 296K CFS design capacity. It may be that the latter is the capacity without regard to damage done to the spillway itself, where the 150K CFS is the designed capacity without damage.
The weir is, of course, uncontrolled and no design capacity is given that I have been able to find. Disclaimer, I have only scanned said documents for keywords and have not read through them.
Vis a vis repairs: there isn't going to be much of a dry season. Runoff will continue through probably July this year, then a break until maybe oct/nov when storms usually start up.
The other thing that hasn't been mentioned here, iirc, is that there is a power plant at the base of the dam. It has been damaged during this incident, but when it's repaired and running it can pass up to 13000 or so cfs by itself, and draw much lower than the spillway.
So first order of business is fix the power plant, switch to using that instead of the spillway, then evaluate the main spillway.
To buy time for repairs to the main spillway theyll have to draw down and hope there's no major inflows during construction.
Repairs to the auxiliary spillway are ongoing and will continue.
Yeah... Snowpack is at 150% of average right now. Once that starts to melt they can't really stop operating the dam, and assuming we don't immediately return to drought conditions, it used to be normal for that area to have very wet Falls.
Posts
E:
http://www.latimes.com/local/lanow/la-me-ln-oroville-weather-forecast-20170216-story.html
@Pellaeon
Source?
Edit: ah I see, wasn't getting those numbers here but downstream so I don't get the same level of accuracy for that area. Also sounds like they revised it recently. Fun times...
In short, this damage is caused by cavitation, which is also how pistol and mantis shrimp hunt their prey. Basically, as millions of gallons of water rush over the concrete spillway, tiny cavitation bubbles are formed on the surface of the concrete due to the rapid changes in pressure cause by such amounts of water moving at such speed. As the bubbles collapse, they release energy that over time damages the structure, eventually resulting in the collapse seen above.
Interestingly, arreration gates can be installed to avoid this exact scenario, as was done in the 80s following similar problems at the Glen Canyon Dam in Arizona and subsequently Hoover and Blue Mesa dams, however this particular dam in Oroville never received the upgrades. They're now looking at repair costs in the billions while the preemptive fix of installing arreration gates would have cost only a few million.
Rain's started, here's the current state.
I know the practical effects of it are shitty and dangerous, but the mechanic of it is actually really neat and something I would have in no way thought of.
Monday in particular is going to be crazy
Incoming!
So Monday evening will definitely be the time to keep an eye out on the dam - if we can make it through Tuesday, I think we should be out of the woods.
https://m.facebook.com/story.php?story_fbid=1683579861668957&id=100000508772678
Per county supervisor:
Peak inflows over 100,000 cfs, but average under 70,000.
Minimal additional damage to spillway (major concern was upwards creep of the collapse)
"Nothing even resembling a problem."
Per me, they've cleared a lot of room over the last week or so to deal with storms.
Spring, with sustained runoff from the melting heavy snow over this year is more worrying.
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I was concerned your drought was gonna break in this fashion. I really was hoping for a nice extended minor deluge that the ground could've kept up with.
Glad to see things are looking a bit more under control.
and in 1000 foot tall letter above that it should read "HEY MAYBE WE SHOULD ACTUALLY FUCKING SPEND MONEY ON INFRASTRUCTURE"
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Good news! Hippies have volunteered to write the image in moss!
Mosses are pretty slow growing. There are two classes of moss, and the faster one can approximately double in size in ideal conditions in 6 months.
I mean, yes, but that's not really what happened here. They could have put in the aeration gates, but I don't know that California has done many of those. The federal dams have, but it seems to be mostly for the flood control dams that use the spillway much more often.
Even when that happens, I imagine the process would make for a pretty neat timelapse.
It's just how we roll. Last year we were having floods and wildfires at the same time. Nbd.
Somewhere in my possessions I have a picture from my youth growing up in West Palm, which is of a "Danger: Extreme Drought. Do not dispose of cigarette butts" sign that was posted in the drainage ditch along the highway. Everything but "Danger: Extreme Drought" was under about 3 and a half feet of water from a week of insane thunderstorms.
They dropped it 50 feet since the crisis, so they have a decent amount of a storage. They've dropped the outflow from 100k cfs to 60k since then, looks like it's only recently exceeding that in inflow (90k cfs or so)
And just think, events like this will only become more common due to global climate change increasing the intensity of weather around the world. Yay!
Yeah but once those snow caps stop forming you'll have nothing to worry about.
http://sanfrancisco.cbslocal.com/2017/02/21/rescue-crews-pull-residents-from-flooded-homes-in-south-san-jose/
It's easy to figure out. 810,714 acre-feet to 1 cubic kilometer.
Basically the same as my odds of piloting through an asteroid field while being shot at by the Empire.
Dam well.
Dunno. Storm that hasn't hit yet was expected to fuck the Bay Area and the Central Coast pretty bad but it looks like it's calmed down. Looking at the storm system it didn't look like it was really hitting further North.
I guess wait until the dry season, drain as much as they can and then bust ass to get the spillway fixed?
I wonder if they'll shore up the emergency spillway first
Vis a vis repairs: there isn't going to be much of a dry season. Runoff will continue through probably July this year, then a break until maybe oct/nov when storms usually start up.
The other thing that hasn't been mentioned here, iirc, is that there is a power plant at the base of the dam. It has been damaged during this incident, but when it's repaired and running it can pass up to 13000 or so cfs by itself, and draw much lower than the spillway.
So first order of business is fix the power plant, switch to using that instead of the spillway, then evaluate the main spillway.
To buy time for repairs to the main spillway theyll have to draw down and hope there's no major inflows during construction.
Repairs to the auxiliary spillway are ongoing and will continue.
Yes.
The spillway a week ago was running at 100K CFS, and has a maximum design capacity of 150K CFS according to the California Department of Water Resources FERC document. Apparently the Feather River hit a maximum flow of 290K CFS in March 1907, by the by (page 50). That same document at page 59 describes the emergency spillway as having a 296K CFS design capacity. It may be that the latter is the capacity without regard to damage done to the spillway itself, where the 150K CFS is the designed capacity without damage.
The weir is, of course, uncontrolled and no design capacity is given that I have been able to find. Disclaimer, I have only scanned said documents for keywords and have not read through them.
edit: bonus crazy-ass pictures of the damage and emergency repair-work found here: http://www.mercurynews.com/2017/02/19/oroville-dam-dramatic-photos-show-damage-to-dams-emergency-spillway/
Yeah... Snowpack is at 150% of average right now. Once that starts to melt they can't really stop operating the dam, and assuming we don't immediately return to drought conditions, it used to be normal for that area to have very wet Falls.
Yes, but it's enough to keep up with inflow outside of major storms coming through.