Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
3/4 to 2 inches of precip fell in the drainage basin the past 24 hours
look like another 1 inch or so the next 24 hours but much of that should be snow..
there will be isolated thunderstorms today in the foothills..hopefully not over the basin
big warm up by thursday may cause some snow melting
longs range models now show a very active wet pattern 8-14 days out
Fantastic information, ER. This tells me that the spillway MUST be completely replaced. Seems that designs have changed over the years.
I wonder how long this one would have lasted if it were used frequently.
LAKE ALMANOR..large lake upstream
for some reason the levels are always 7-10 days behind
the article on FEB 20th said the max elevation is 4494 feet
well on the 20th it was 4493.22 feet
no news since
from the article
uring the recent storms, PG&E operators have worked to keep the popular recreation lake below the 4,494-foot elevation maximum, releasing water through a small outlet at the base of the dam as well as a tunnel to Butt Valley Reservoir, 10 miles south of Almanor.
Despite their efforts, water is flowing in as fast as it is flowing out, said Plumas County Supervisor Sherrie Thrall, who represents the Chester/Lake Almanor district. While most reservoirs have the possibility of spilling water during an emergency, spilling water out of Lake Almanor is not an option, she said.
Most of Chester is below the 4,500-foot spillway. If reservoir managers were forced to release water over the spillway near Canyondam, large portions of Chester would be inundated.
“That’s why PG&E is working so hard to maintain a lower lake level,” said Thrall.
Read more here: http://www.sacbee.com/news/weather/article133818604.html#storylink=cpy
I am almost certain that investigation will show that there was significant void under the area that failed - that the fill beneath the spillway had failed through that area. Looking at how the spillway above that has held up, and below that also, though it was obviously abused and undercut by violent waters once the hole occurred.
There is much work to be done.
Yikes!
I’ve tried to find up-to-date information on Lake Almanor also, but nothing seems to be out there.
Oroville's slab design created a 40% reduction in thinning of the slab from the placement of intervals of drain pipes & gravel - forming a inverted "V" of non-concrete.
This almost looks like a last-minute "Whoops, we forgot about the drain pipes. Well we'll just lay them on top of the ground and thin out the slab." Either that or someone's idea of saving time, money and/or work.
this mornings GFS model just in and its not looking good..keep in mind this is just one model but is one of the main ones used..and will likley change
to sum up...
next couple of days.....precip mostly snow 1-2 inches of total precip
then a break but warm up..
next sunday on ..a very wet warm pattern similar to last month with warm wet storms every 2-3 days thru the end of the model run(march 21)
The GFS last night was the wetter model..the other models had the high pressure stronger forcing the systems more north...
DWR will have this data soon
what to do?
right now the lake is 853 feet..up around 15 feet since the main spillway was shut off...
Do you turn the main spillway back on NOW and keep in going until you let out as much water as you can...then start the debris clean up over again?
Or so you let the lake creep up and hope you get all the 14.000 cfs out soon.
regardless, 14k CFS is nothing as inflows could be over 100K in 2 weeks if the GFS is correct
Thanks Janet for posting the update.
This guy is trying to bring a bit of calm reason where there seems to be a lot of panicky rumors flying around. From what Juan Brown is saying, the situation is problematic but appears manageable.
Good video. I like that guy. He’s pretty matter-of-fact in his delivery.
I think they dredge the channel of what debris and wash-out is causing backup to the power plant. If they can put it back into operation with 14k of flow, that is about a sixth to a third of what they need and that can help allow another shut off in the future for the main spillway.
Looks like they might be generating again. I see outflows of over 1400 gps for the last hour!
1735 for hour ending 1900 (7 PM, Pacific time). There’s definitely a generator on line.
janetjanet998 wrote:
“unconfirmed............
hearing reports on social media that part of the mountain side gave way and caused the powerplant to fill with debris
the are trying to clear it
0 outflow at this time”
Freeper abigkahuna lives right near there, and another; the name escapes me.
Wonder if they’ve heard anything.
Abigkahuna, courtesy ping, & if you’ve any info/updates.
Thanks for the update on the weather forecast.
Check out abb’s post of the end of the main spillway...
in reference to image at 2256 - That is the area that I was thinking needs to be shored up if possible. They will likely need to use the spillway again, and the area right at the end is vulnerable to undercutting and failing, which would introduce another mass of earthen debris into the river below.
My thought is to not only shore it up but build up a sloping surface into the bedrock below so that they can use the spillway at lower flow levels with minimal erosion as a means of assisting the plant’s output in the coming spring thaw.
Interesting. I am surprised that there is any loose rock left in the area. “Drain” pipe is clearly visible.
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