Erosion has created a 300-foot-deep hole in the concrete spillway of Oroville Dam and state officials say it will continue grow.
State engineers on Wednesday cautiously released water from Lake Oroville's damaged spillway as the reservoir level climbed amid a soaking of rain.
Situated in the western foothills of the Sierra, Lake Oroville is the second-largest manmade reservoir in California after Shasta....
DWR (State of Calif) has a financial interest to store as much water as possible in their reservoirs, both for water delivery contracts to downstream municipalities (sale generates cash) and for power generation (sale generates cash). As noted by Spartan and others above, high surface water elevations are the annual goal, and not a short term test, as attested by historical data.
The Lake Oroville level is approaching 11 feet of where it would start to flow over the emergency spillway, and it continues to rise at something like an inch or so per day, as shown on the website below. Granted, at that rate, it'll probably never reach anywhere near that level, but the reservoir is basically 'full-to-the-brim'.
While I'm no expert, I believe the 'TOC STO' field represents the target storage amount, which is now 'maxed out' but the lake is still 170K acre feet below this amount.
You can also see that the total inflows are decreasing and are only slightly higher than the outflows they are sending through the power plant.
As ATSE says, the goal of the operators is to try and fill it 'to the brim' but not over...
'TOC STO' means top of conservation storage. (I just looked it up)
"The top of conservation storage marks the bottom of the “flood storage.” Flood storage is the depth allocated to capture surplus water during intense rainfall events. Also, the bottom of conservation storage marks the top of the inactive storage pool—the lowest layer of water in the reservoir, designed for collecting sediment."
That and it's really kind of warm as in the night temps are often 60F at 2AM. Any rain could get the snow pack a bit excited. It will be interesting to follow.
They have 170,000 Acre-feet of storage room 'left' in the Conservation pool. If you look at the rate of change in AF, you can see that even a month ago when the inflow was much higher, the reservoir was only gaining about 15-20K AF a day:
They could also use the FCO (spillway) again if they really need to. Perhaps the only issue might be that they are still working on repaving/rehabbing the boat ramp area, I'm not sure if this area is underwater if they reach the top of the Conservation pool:
But for the nutjobs stirring up anxiety in the community, this seems like much ado about nothing.
So far this season they've had a few spikes in the inflow of 40,000 CFS range with one burst at 67K CFS. They've tested the spillway at 28,000 CFS and by every indication it has passed with flying colors. It looks like for all intents and purposes that the system can handle whatever is thrown at it.
And even if there is some massive government coverup conspiracy i(involving every engineer on the project), we've seen what the worst case scenario looks like; the unzipping of the primary spillway down to bedrock.
It appears to be raining in the Oroville area as seen both from the webcams and the weather radar (see the screen grab below from the current radar weather map):
That right most gate has got "the leaks". Oh wait. They put in sandbag dikes. They're all leaking uniformly as expected. It's just being herded down the left side. I think someone actually mentioned this earlier.
There may have been rain to the east of Lake Oroville on Wednesday but by evening it was snowing in the Sierras and that continued trough Thursday. Here in the SF south bay on Wednesday the temperatures were mild until about 7pm, when a pounding squall came through and then the temperature dropped swiftly by about 10F to 15F. I don't think this storm excited the snow pack but we'll have to wait and see what the weekend storm is like.
In Juan Browne's video I posted earlier, he mentions that I-80 was forced to clos the night before for awhile due to snow in the mountains. He posted his video on Thursdays so that sounds about right. He mentioned that the rain on Thursday, which was falling while he was shooting his video, was very cold so he wasn't sure that it would contribute to much snow melt.
Anyone notice how it's actually crows that run the spillway gates? There is almost always at least one crow standing on some part of the gate actuators. One landed on the farthest box and turned 30 revolutions on it. Made me dizzy watching it.
![[smile2]](/data/assets/smilies/smile2.gif "[smile2] [smile2]")
