California Drought

[jerrybob]

Most of your politicians should be taken out and.......

Aborted! (Friendly politics.....here we come!!)

 

[California]

Looks like the Orville dam has failed. Anyone watching this.... Water has migrated around dam completely and is draining the lake 3/4 of the way below the emergency spillway. Just time now. If main spillway can't drain lake quickly enough and there's not much chance of that now, there's going to be a catastrophe.

Relax, Oroville Dam isn't failing, only the overflow spillway next to the dam. The concrete spillway is disintegrating and soil beneath the spillway is eroding a few feet down to bedrock but it can't erode that. None of this affects the primary dam.

Beyond that concrete spillway, when the dam was built they leveled an area for an Emergency Spillway that is at lower elevation than the primary Oroville Dam. If the reservoir reaches capacity, water will overtop that and it will dump a broad sheet of water down a native hillside.
The forecast this morning is the rain has ended and the reservoir is no longer rising, so that emergency spillway is not likely to be used.

The real consequence here is a huge amount of erosion debris in the channel below the dam and headed down to the fish hatchery below. F&G is presently trucking the salmon over to another hatchery. Aside from that, downstream consequences should be minimal.

Another set of photos (click right arrow)

 

[aczlan]

Looks like the Orville dam has failed. Anyone watching this.... Water has migrated around dam completely and is draining the lake 3/4 of the way below the emergency spillway. Just time now. If main spillway can't drain lake quickly enough and there's not much chance of that now, there's going to be a catastrophe.

Got a source? Everything I am seeing says nothing of the sort. The concrete spillway has a hole in it about 1/3 of the way down, but that is built on bedrock and shouldn't let water go the wrong way. Both spillways are a ways away from the dam itself and are positioned so that they wont let the water erode the dam itself:

Source: Oroville Dam Spillway Failure | Metabunk

Aaron Z

 

[RedNeckGeek]

Looks like the Orville dam has failed. Anyone watching this.... Water has migrated around dam completely and is draining the lake 3/4 of the way below the emergency spillway. Just time now. If main spillway can't drain lake quickly enough and there's not much chance of that now, there's going to be a catastrophe.

You must know something I don't, and I live above Lake Oroville. Here's a shot taken from my back porch a few minutes ago:



As you can see, the water is almost to the tree line, which coincides with the top of Oroville Dam. I think I would have noticed it if the dam was "draining the lake 3/4 of the way below the emergency spillway".

I would hope people would verify the information they post, especially something as life critical as this. But in this day and age, I guess that's just too much to ask.:muttering:

The main spillway is damaged, that's all:



They've continued to release water down the spillway since that photo was taken, and the hole is much larger as a result, and the concrete continues to erode down the spillway. I've been watching the KRCR-TV web site for info, and they seem to be posting pretty much in real time.

 

[aczlan]

Another picture of the damaged main spillway from today (as I understand it):


Aaron Z

 

[houstonscott]

Where did the water come from that eroded the soil away under the emergency spillway concrete, and cause it to collapse?

 

[prichard]

From the lake as designed

 

[aczlan]

Where did the water come from that eroded the soil away under the emergency spillway concrete, and cause it to collapse?

The concrete of the spillway was bad and it eroded from the top down. As I understand it there are pictures of trucks parked in that spot and people inspecting that section or within 50 feet of that section back in 2015.

Aaron Z

 

[houstonscott]

The concrete of the spillway was bad and it eroded from the top down. As I understand it there are pictures of trucks parked in that spot and people inspecting that section or within 50 feet of that section back in 2015. Aaron Z

The lake was dry in 2015, no water had ever gone over emergency spillway since 1968.

 

[houstonscott]

Another picture of the damaged main spillway from today (as I understand it): <img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=498293"/> Aaron Z

Looks like half is gone now, not just a hole.

 

[aczlan]

Looks like half is gone now, not just a hole.

Fast flowing water will do that...

Aaron Z

 

[aczlan]

The lake was dry in 2015, no water had ever gone over emergency spillway since 1968.

Correction, 2013, not 2015.
Here is the picture:

Source: Photos from Shaner Jeff's post in You know you grew up in Oroville, CA...

Aaron Z

 

[houstonscott]

Correction, 2013, not 2015. Here is the picture: <img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=498326"/> Source: Photos from Shaner Jeff's post in You know you grew up in Oroville, CA... Aaron Z

So, California didn't do all the dam maintenance in the State during the drought, special kind of stupid there...

 

[prichard]

I wonder if since it was built on bedrock if seismic activity caused it to shift away from the rock. Also it bedrock is directly under the concrete I can see it being a low budget priority.

 

[ForestGrump]

So, California didn't do all the dam maintenance in the State during the drought, special kind of stupid there...

When dams are having major maintenance they are also retrofitted for new seismic requirements. This can cost up to $400 million for one dam and years of planning and permitting. There are 100's of dams. It's a big state.

 

[orezok]

Houston Scott

The sky is NOT falling in California. :laughing:

 

[RedNeckGeek]

The concrete of the spillway was bad and it eroded from the top down. As I understand it there are pictures of trucks parked in that spot and people inspecting that section or within 50 feet of that section back in 2015.

Aaron Z

A neighbor posted a picture on our neighborhood Facebook group this morning showing four or five white pickup trucks parked on the dry spillway just above a large water stain that extended almost all the way across the spillway. That photo was said to have been taken in 2003, and if that's correct DWR has known of water problems under the concrete for a very long time.

The water level increase has slowed since yesterday, but it's still up 4' from this morning. It is now 3' from overtopping the emergency spillway, which officials now think will occur sometime early Saturday morning. Right now inflows are running about 120,000 CFS. Half of that is being put through the power plant and over the spillway, leaving the rest to raise the water level. Once that happens, 60,000 CFS or a bit less will be dumped over the emergency spillway. Hopefully the ground there is solid and erosion won't cut back to the lake itself. My guess is that they had that area laid open down to the bedrock during construction of the dam, and made a good choice when selecting the emergency spillway location.

If there were a real emergency it would be all over local TV and radio, and it isn't. But it will be interesting to see what happens, especially for those living along the Feather River downstream of the dam.:shocked:

 

[dragoneggs]

Houston Scott

The sky is NOT falling in California. :laughing:

Nope the water rising! Build an Ark! :laughing:

 

[RedNeckGeek]

This photo was taken yesterday morning when the spillway was shut down for inspection. It shows the exposed bedrock below the concrete, and I think I can make out some rebar in the concrete. Keep in mind you're looking across about 200' of material, 2/3 of a football field, so small details like rebar are gonna be difficult to see. Easy to understand that the water will continue to undercut the spillway concrete, but once it reaches rock it's not gonna go very much deeper.

 

[dragoneggs]

View attachment 498375

This photo was taken yesterday morning when the spillway was shut down for inspection. It shows the exposed bedrock below the concrete, and I think I can make out some rebar in the concrete. Keep in mind you're looking across about 200' of material, 2/3 of a football field, so small details like rebar are gonna be difficult to see. Easy to understand that the water will continue to undercut the spillway concrete, but once it reaches rock it's not gonna go very much deeper.

Great shot RedNeck... will be interesting to follow this story.