The Oroville reservoir is nearly full and storms are putting more water in than the failing spillway is letting out.
http://www.sfgate.com/news/article/Oroville-Dam-spillway-hole-erosion-water-reservoir-10920358.php
Estimated cost of damage o date is $100 million.
Paul in PA
Good news is the rain is ending for a week or so.
The lake is 3-1/2' below the emergency spillway which probably won't be needed but contractors are clearing trees and brush from the channel below.
Water is flowing down the spillway now 55,000 cfs which is causing more damage but they don't have much choice. 115,000 cfs is flowing in but dropping.
Meanwhile a freight train running on a levee has derailed in south Sacramento County. The Cosumnes River is peaking in Wilton.
I need to stop in the County Recorder and County Surveyor in Oroville on Monday. We are surveying the boundaries of our Magalia Nursery (east of Chico).
Dave Karoly, post: 413547, member: 94 wrote: I need to stop in the County Recorder and County Surveyor in Oroville on Monday. We are surveying the boundaries of our Magalia Nursery (east of Chico).
I hope your experience there is better than mine. Some of the maps I needed were misindexed in their scanned file system, and they don't keep paper copies around. When I asked where the originals are I got a blank look, and when I asked if they might be in a county archive somewhere I was told, "Maybe."
It's a very spiffy new facility, though.
Jim Frame, post: 413548, member: 10 wrote: I hope your experience there is better than mine. Some of the maps I needed were misindexed in their scanned file system, and they don't keep paper copies around. When I asked where the originals are I got a blank look, and when I asked if they might be in a county archive somewhere I was told, "Maybe."
It's a very spiffy new facility, though.
It's an interesting survey...fortunately Walker was there in 1958 and left a lot of information about where the corners are. The northeast line is the Paradise Reservoir take line.
Weather patterns have certainly been strange the past several years. Global warming or is the earth slowly tilting on its axis?
1969
1986
1997
2017
The Oroville Reservoir is now 100% full and water is flowing over the emergency spillway.
From what I see at least 300' of the regular overflow spillway is gone.
Paul in PA
Jim Frame, post: 413548, member: 10 wrote: I hope your experience there is better than mine. Some of the maps I needed were misindexed in their scanned file system, and they don't keep paper copies around. When I asked where the originals are I got a blank look, and when I asked if they might be in a county archive somewhere I was told, "Maybe."
It's a very spiffy new facility, though.
wait, they don't have they originals available?
Edward Reading, post: 413602, member: 132 wrote: wait, they don't have they originals available?
I didn't press the matter beyond the Recorder's Office front-line staff, as my time was limited and I had enough information to do what I needed to do. I (optimistically) assume that the County Recorder does, in fact, know where the originals are housed and how to provide access to them, but Butte County ranks as one of the most challenging I've encountered when it comes to map research.
Most government offices do not have the budget to store the digital data and find room for the originals.
The originals are usually archived, aka stored in some location that was not recorded and either wastes away or winds up in the shredder room.
Locally, when the computers go down, record search is futile.
All i can say is wow!
Evacuations in Oroville...DWR says emergency spillway could fail soon.
Decided to learn a bit about Oroville. On the list of notable persons from Oroville was the name of the individual featured in the link provided here. Very interesting reading. Including the mention of how surveyors in 1908 had a negative influence on his life.
Water Storage can be a challenge and nature will always be the winner.
Living inside an area marked with various and multiple areas of watersheds has taught me that not just anything put into place will store water very long, it will find a way downstream.
The efforts to maintain any substantial framework of a dam facility is a day by day monitoring necessity.
Dam blowouts and failures begin below the surface and in certain areas knowing that the existing structures are prone to failure is just a waiting game.
Every lake and reservoir has experienced a period of doubt and has to have major
overhaul to certain parts of their system to continue in place and function.
This occurrence looks to be close to or beyond repair and may be key to understanding where California's water is going.
Locally there is an area called Lost Creek. From the spring that gives it life to where it spills into Frazier Creek, there is a large abundance of natural water that follows the route and it gets the name because in many places sandbars cover the underground channel where the water keeps constant flow downstream and many attempts to create lakes and ponds simply disappeared after a heavy rain.
I spent 4-1/2 years as earthen dam designer for the SCS in Kansas. Qualified me for my PE during that time. It's a serious business. I read a lot of literature including about dam failures. That auxiliary (emergency) spillway would have been designed considering that every bit of overburden above bedrock would be stripped if it ever flowed more than a little. Its hard to tell from the reports what is going on here, sounds like maybe there is a crevice in the bedrock which the flow is washing away, what you'd expect, but was the soft overburden identified in the geologic and engineering studies and even more important does it extend under the dam. I doubt it goes under the dam itself because that would have been stripped clear to bedrock before they placed the concrete. But without seeing the design and construction documents, no way to make any real constructive comment.
Needles to say, this is a bad situation. If that auxiliary spillway did break then its a function of how much water is released and how much energy it takes to erode the spillway path. Hopefully the bedrock would survive and you wouldn't get a cut through the whole foundation, releasing most of the storage in the reservoir. That would be an epic disaster.
Even if this thing holds, (I think it probably will) I'd expect the next situation will be the loss of the badly needed water to help cure California's drought. Don't know about this one (this big) but standard procedure for a dam when it needs a major repair like this one's spillways is to release or draw down the storage to where potential inflows don't threaten over-topping of the dam. Probably all the water in this case. That water is probably headed to the ocean or somewhere they can't use it. Once you build a dam you have a major maintenance problem for ever.
California has quite a history of dams:
Big powerpoint:
http://web.mst.edu/~rogersda/dams_of_ca/Dams-of-California-Presentation-2012.pdf
Let's pray another chapter about the epic failure of the Oroville dam isn't added.
The estimated repair bill for the normal spillway is already between $100 and $200 million. Add in the repair to the emergency spillway and there went a whole bunch of tax dollars.
There has been withholding of information to the public.Yesterday it was impossible to get any updated video. The few photos I found indicated the severe erosion below the emergency spillway. One photo showed the water level covering the parking lot to the northwest of the emergency spillway, with runoff to areas never anticipated in the original design. The most recent video shows that the emergency spillway was not founded on bedrock and as the erosion continues would undermine the emergency spillway. hey are talking about a 30' wall of waterway, which I say is a severe underestimate. That 30' may be the level of water released at the full reservoir level, which will increase as that water funnels into the narrower river valley.
I spent hours on the phone with my brother, another engineer and we pieced together information from many sources.
Our concern is that the reservoir has been very low for a long time and they allowed it to fill to capacity too quick to properly allow the earthen fill to resaturate. There are unknown changes within that dam due to that rapid resaturation. I would say that policy makers over rode the engineers on time to refill the reservoir.
Of even greater concern is that the snowpack above the dam is 150% of normal. Repairs cannot be made in time to meet the expected spring peak flow.
Oh, by the way this is California and even the slightest tremor could cause failure of the 770' high main dam.
Environmentalist have requested for years that upgrades be made to the emergency spillway, well now that repair can start with a fresh drawing board. Speaking of environmentalists the Cal people had been busy this past week trying to evacuate the salmon downstream and only got around to the people yesterday.
Paul in PA
The office manager just reminded us to do a really good job on our spillway monitoring jobs...
