I’m guessing that’s why they named it “Oroville”. Gotta be some gold in them parts…Aloha, Steve.
OROVILLE DAM (ORO)
Elevation: 900’ · FEATHER R basin · Operator: CA Dept of Water Resources/O & M
Hourly Averages (Link)
Daily Averages (Link)
Looks like they’re not expecting the inflow to exceed the outflow over the next week or so, even with the rainfall that’s forecasted. That, along with the repairs they’re making, they should be good to go. Here’s the GFS total rainfall output for the next couple of weeks:
If I were in Oroville, I wouldn’t be trusting my and my family’s fate to forecasts and government assurances. I’d be using this time to gather and move out as much as possible to higher ground. The local authorities have shown more than once that they are a day late and a dollar short when it comes to warning the people adequately.
Canadian model just went ballistic with rainfall for NorCal over the next 10 days. The 12z GFS isn’t quite as wet, but it’s wetter than it’s 6z run and 0z run.
Taken Monday Feb 13. This angle shows the depth of the erosion channels.
Well its 12:20- PST and the Oroville reservoir level listed at 859 feet, so they almost got it down to the 850 feet they wanted before the rain. http://rdcfeeds.redding.com/lakelevels/oro.cfm
Judging by the rain we have been getting in Sonoma county all morning that will reverse soon as the storm makes it there. The storm that was supposed to arrive Thursday did not amount to much thankfully and there has been a long lull till now. Snow level expected to be 6000. Luckily the really heavy rain falling much furthur south for this system.
But we still have a long period of potential rain…into June not unheard of, and all that snowmelt still to accomodate…most spots in Feather River Basin are close to or exceeding 100% of average.
https://cdec.water.ca.gov/cgi-progs/snow/COURSES.02
Maybe the engineers who designed the damn needed to plan for a 10,000 year event. But more than likely we are entering a cycle of unprecedented 1,000 year and 10,000 year events happening more often. Welcome to the Anthropocene.
Here’s a good commentary from the Mises Institute. Marc Reisner is the author of Cadillac Desert, probably the best book on water in the Western US.
https://mises.org/blog/who-will-be-blamed-if-oroville-dam-fails
Certainly it seems that the situation at Oroville dam has stabilized and is well under control. The water levels are way down, and seemingly safely so.
However, there’s an indeterminate but probably significant amount of rain on the way. Deserves watching, of course.
So hopefully out of the woods, but there might be a few trees scattered about in our field of view yet.
I live about 100 miles SW of Oroville, near the coast. The rains today have arrived in earnest.
I’m checking the dam water level at Oroville hourly to see if/when it starts rising again. So far so good, but I expect a reversal to happen within the next few hours given the rain intensity.
I’m a little surprised to see the rain inches accumulated at the Oroville dam haven’t changed in the past 4 hours, given that it’s been raining steadily all day where I live and that Oroville should be getting my weather within an hour or two. Perhaps this storm is just moving really slowly.
Anyways, I’ll be surprised if the dam levels don’t start rising by nightfall.
The real question, to my mind, is what is the ratio of the area that the lake drains, to the area of the lake? I suspect it’s very large: let’s have a hypothetical 10:1. So suppose 1/4" falls on the lake. The 1/4" is added immediately to the lake height, and by dam management may not even be seen.
But then, over the rest of the land, the water hits the trees, and from the leaves drips down to the ground; and along the ground makes rivulets… and from thence to streams, and from streams to the rivers… I’ve seen the streams delay on a strong run for hours… rivers for a day. So I’d expect that you’d see 1/4" the day of the storm on our hypothetical lake, and 2.5" the next day, when it’s not even raining.
In the same way, I don’t think you’ll see the big impact of your storms immediately… and when the storms are gone, you will see the levels still rising (assuming that they don’t fall suddenly).
Michael -
I largely agree. Inflows to the lake will accelerate the longer the rains last as the runoff from all the regions and tributaries that flow into the lake compounds.
When I lived in Palo Alto, there was a series of dams up in the Santa Cruz mountains that ultimately fed into the creeks in our town. While our creeks would flood from heavy storms, given the time it took for the water to flow down from elevation, oftentimes, they didn’t crest until many hours after the rains had stopped.
But looking at the Oroville dam levels today, the rate of decrease has slowed dramatically, sometimes only dropping a few tenths of an inch per hour. With the storm system now here, a small increase in net inflow to the dam should be all it takes to start pushing the lake level back up.
If that indeed happens, like you, I expect the rate of rise to then accelerate hourly over the next few days as the combined runoff from the surrounding watershed makes its way into the lake.
Hi everyone,
I want to share two great sources of as it happens weather information. Once source I follow that is very specific to California is Daniel Swains’ Twitter feed. He also has a great blog called Weather West. Last night he posted about the possibility that the current atmospheric river hitting Northern California will stall particularly impacting the Santa Cruz mountains.
Second, I track the comments section of the latest post on Wunderground’s Category 6 blog. Many people post up to date information there. This very early morning I find a disturbing post there from a meteorologist named Eric Holthaus warning of epic flooding in Northern California, particularly if the atmospheric river stalls.
So far it looks like the brunt of the storm is impacting areas south of Sonoma County where I live. I hope everyone stays safe.
–Suzie
suziegruber wrote:
Second, I track the comments section of the latest post on Wunderground's Category 6 blog. Many people post up to date information there. This very early morning I find a disturbing post there from a meteorologist named Eric Holthaus warning of epic flooding in Northern California, particularly if the atmospheric river stalls.
Hi all,This is an urgent and important message, so I'll keep it short. If you're in a hurry, please read and retweet this message.If you have family or friends in northern or central California—please get in touch with them on Monday morning, or sooner. The seriousness of the potential flood that is inbound on Monday and Tuesday cannot be overstated. I just got off the phone with a NWS meteorologist at the Sacramento office, Bill Rasch, and he said they are increasingly concerned about the potential for the incoming atmospheric river to cause substantial or even historic flooding with little immediate notice. They are urging people to prepare to evacuate with less than 15 minutes warning, and expecting flooding in places that haven't flooded in "many years." As far as the this sort of dire wording, they have tentative plans to "take it up a notch" tomorrow—this is the real deal, a situation that likely hasn't hit California in decades, or maybe much longer.Here's what is causing so much concern: If the atmospheric river stalls, there could be up to a foot of rain in a span of about 36 hours over places that are already flooding—that's a rainfall intensity that isn't expected more than once a century, or even more rare. At risk is the vast network of levees and dams and diversions that literally make modern California what it is, and protect hundreds of thousands of people. If this system is compromised, the scale of disaster would be among the worst in U.S. history. A dire 2011 New York Times magazine piece outlines the scenario. It's not pretty. The implications of this flood would be huge: If the levee system is breached, Sacramento could have 30ft of flooding, and much of the state's water delivery system could be paralyzed by an influx of saltwater, including much of southern California. Two-thirds of people in the state could lose fresh water. That's not to mention the potential loss of life. Of course, this is not a given based on the latest weather forecast—but the fact that it can't be ruled out should cause everyone in the region to pay close attention.This is something that should be wall-to-wall national coverage, but I haven't seen circulated much so far. Please help get the word out.Thank you so much,Eric
Here is the GFS precipitation forecast from last nights 06 UTC (10 PM PST) forecast for hours 0-48:
Yellow is 7"+, mustard is 6"+, orange is 5"+, red-orange 4"+ and orange 3"+. The heaviest precipitation is near Tahoe, but the Feather River area is close behind, with smaller areas of 7"+. Most of that precipitation is forecast to fall in the first 24 hours.
Current snow levels are nearly 7000’. Here are temperatures in the Feather River basin right now:
To see current values, go to: http://mesowest.utah.edu/cgi-bin/droman/mesomap.cgi?state=CA&rawsflag=3 Select “all networks” and click “Refresh Map” in the control panel at left, then zoom and pan as appropriate. Click on each station to see it’s elevation in the gray bar at the top of the pop up window. Currently most 32° stations are just below 7000’ which is higher than most of the terrain in the Feather River basin - so mostly rain now.
Finally, the current radar image:
Yes, heavier precipitation in the Tahoe area, but not by much.
It is raining hard here in the Sierras this morning. So far my permaculture swales are full to the brim and holding. The seasonal stream running through my front yard is peaking and has formed a whirlpool about 6" above the top of a 30" diameter culvert running beneath the driveway. That has not happened since I moved here in 1985!
But I live about 1500’ above the Tuolumne River so that brings a measure of relief. It is wet but there is no chance of the house being flooded … as long as the roof stays on!
The Don Pedro Reservoir (on the Tuolumne River which drains Northern Yosemite Park) may spill its emergency spillway this afternoon. That has only occurred once before since it was constructed in the 1960s. That happened in 1997 during a rain on snow event in the Western Sierras. If that happens again it will take several days for the floodwaters to migrate West into the California Delta region which is already at flood stage this morning. Expect things to develop fast in the Sacramento/San Joaquin Delta Region today and tomorrow.
It is amazing how fast we have transitioned from a multi year drought into a major wet year with flooding events. Be prepared, changing times are certainly upon us everywhere.
Coop
The 2 inch plus region more or less corresponds with the upper feather river basin. Just through 4 AM PST this morning.
source
Here is the 24 hour rain gage observations ending 21:57 UTC (1:57 PM PST) for today, 2/20/17. This includes all networks. Some stations might not be well maintained and could be reporting bad data.
For the first time in a week, the water level in the Oroville Dam is now rising (very slighty):
As mentioned in earlier comments, this rise will likely accelerate over the coming hours/days due to continued rains and runoff from the surrounding watershed.
Fortunately, the engineers there were able to get the lake level down below their safety target of 850 feet, so there’s substantial buffer space in place. Now, it’s just a matter of how much more rain Mother Nature wants to dump into the watershed over the next few days.
At this point, things are looking better for Oroville (though worse for other parts of California). But we’ll keep monitoring the situation closely…