California drought photos. Oh my. . .

[Cudedog]

Ran across this article this morning.

"These photos tell you everything you need to know about California’s drought"

https://www.ksat.com/features/2021/08/20/these-photos-tell-you-everything-you-need-to-know-about-californias-drought/

The water level in Lake Oroville (about 25 miles from me as the crow flies), is dropping about 1 - 1 1/2 feet per day.

The Edward Hyatt Power Plant (electricity) there was forced to shut down back around August 6, due to the lowering water levels. This power plant has the ability to service 800,000 (almost a million) homes when operating at full capacity. At the moment, it is not generating electricity.

A lot of "interesting" photos under the above link, including a few "before-and-after".

Not good.

Ann

[Bethers]

So sad. The speed they are going down is hard to fathom.

[BirdbyBird]

Ann, those are some of the recent pictures I have run across, also. Thank you for sharing them. And logic would tell us that the lower the levels go the faster the levels will go down as the drought continues because there is less volume to subtract from......

[Cudedog]

Ann, those are some of the recent pictures I have run across, also. Thank you for sharing them. And logic would tell us that the lower the levels go the faster the levels will go down as the drought continues because there is less volume to subtract from......

Yes, Tina, you are correct. As the drought continues, and the heat persists (thankfully, a bit of a cool-down just now, just mid-to-low 90's was the high yesterday and today - 100's to return by the end of the week), with no rain, the daily drop in lake level will accelerate. It's physics.

Here is an interesting graph that lets one "plug in" Oroville's lake levels for previous years.

http://oroville.lakesonline.com/Level/

As of today, the lake level stands at 632.44 feet - an astonishing 267.56 bellow "full pool", which is 900 feet.

There might be 80 days before northern California begins to receive rain - and the ground is so very dry, the first rains will have little run-off to go into the dam, because the dry ground will absorb any rainwater like a dried-out sponge.

So the dam will only begin to fill again if/when there is a period of extended rain. We have not had much of an extended period of rain here since about 2017. Which, incidentally, was the last time Lake Oroville was full - well, over-full, actually.

There is quite an interesting video on YouTube that I ran across the other day, "Exploring the Bottom of Lake Oroville: Hike From Nelson's Bar to Cape Horn".
https://www.youtube.com/watch?v=KlhcCYPrlc8&t=366s

The fascinating thing about this video is that this guy is exploring a mostly dried-up arm of the lake from the bottom (at ground level, where water used to be), looking up. Most other videos and photos of the lake that I have seen are from above, looking down.

Looking up in the video - WAY up - one can see the distant tree line at the top of surrounding hills - where the water used to be. It gives quite a different perspective on the situation.

:cry: So sad. The speed they are going down is hard to fathom.

Lake Oroville is where the California State Water Project begins. Water from Oroville is sent to the delta, where some part of it is then diverted on to Los Angeles, that carefree desert land of green grass and full swimming pools [sarcasm].

"California's Water Supply - a 700 mile journey":

https://www.capradio.org/articles/2013/10/07/californias-water-supply-a-700-mile-journey/

I think it best that I say no more on this water diversion thing.

Thanks, Tina & Beth.

Anne

[Bethers]

Don't get me going about desert locations that tried to turn them green. Phoenix for example.

[Cudedog]

Don't get me going about desert locations that tried to turn them green. Phoenix for example.

LOL.

Anne

[Colliemom]

And to think, 4 years ago, the dam was in a critical Stste from too much water and you were worried about possible evacuations. Unbelievable.

[Cudedog]

And to think, 4 years ago, the dam was in a critical Stste from too much water and you were worried about possible evacuations. Unbelievable.

Thanks for the comment, Sue. Yes, I was most certainly "worried about possible evacuations" for several days leading up to the worst of it, winter of 2017.

That is, until I was then evacuated out of my home for six days. Then I was no longer worried about it, I was doing it. Me along with about one-hundred-eighty-eight thousand (188,000) of my immediate neighbors, who also were evacuated.

Here is a day-by-day unfolding of the disaster, with a very nice photo of the damaged main spillway at Oroville Dam to start things off with a bang:

https://projects.sfchronicle.com/2017/oroville-explainer/

More of my post below is below the following photo. Scroll down.

Center top, slightly to the left of the concrete structure, water flowing over lip of "emergency spillway" (white water, below it is brown water as the hillside is being eroded); Center, main (damaged) spillway; to the right of the main spillway is the "canyon" being carved into rock by the water escaping from the damaged spillway.


The Butte County Sheriff at the time, Korey Honea, later said this when he decided to call for the evacuation of the major towns in the area: (the towns of Oroville, Gridley, Live Oak, Marysville, Yuba City, and other, smaller communities that would all have been in the path of the water).

“It was not a question that people would die. It was a question of how many.”

Yes. The lake overflowed down an "emergency spillway" that was nothing more than your basic, un-reinforced, no-concrete, dirt hillside (it did have a concrete “lip” at the top, but that was all). As the lake began to overflow onto the hillside (by this time the damaged main spillway was also put back into operation, but it could not keep up with the water already in the lake, and the continuing inflow still coming in) of course it began to severly erode the ground.

What happened with me in the days previous to the crisis is that I watched the water in the lake rapidly rising, because the primary spillway had failed, and, for a time, had thus been shut down.

I looked at this dirt-hillside “emergency spillway” (that had never before been used since the dam was first constructed) and I thought about how, if a person turns their backyard hose on full force and aims it at the ground, pretty quick the force of the water coming out of the hose begins to dig a hole at the place where the water is being aimed.

Here is a bit of fun math (please stay with me, I am getting to my point - eventually )

The flow out of your average garden hose is about 15 gallons per minute (tops, many garden hoses don't come near this rate). The water from a hose will dig a hole deeper and deeper, the longer a person aims the flow from the hose at a particular spot in the dirt. Erosion.

Looking at it another way, large volumes of water are generally measured in cubic feet, rather than in gallons. A cubic foot of water is about 7.5 gallons (so, at 15 gallons per minute, think 15 plastic milk jugs =/- worth of water squirting out the end of the average hose into the dirt every minute, or cubic feet per minute). Large volumes of flowing water are generally measured in cubic feet per second (cfs).

Doing the math (never fun), converting the hose flow from cubic feet per minute, to cubic feet per second (cfs) the water shoots out of your average garden hose at about .125 cfs. Not very much, really, in the great scheme of things.

As I was pondering this back-yard hose thing, I was also thinking about how the water that had been coming down the main spillway at about 150,000 cfs before it was shut down for a time, and assumed that about the same volume of cubic-feet-per-second was now getting ready to flow down the dirt hillside of the "emergency spillway", eroding the ground as it went – just like my garden hose eroded the dirt in my backyard, but at at an intensity of hundreds of thousands of times greater.

It didn’t take a lot of imagination on my part to see that this could be a bad kinda thing, 150,000 cfs of water gouging it’s way down a dirt hillside unimpeded, so I packed up my van and left my house, driving about two hours to stay with friends in the San Francisco bay area.

I stayed with them about three days, watching the news all the while, those in charge were very assuring that the water would not come over the the lip of the emergency spillway. Whew!! Fantastic!! All is well!!

So, after three days, I got in my van and drove the two hours back home.

When I arrived home, the first thing I did, after walking through my front door, was to turn on my tv - even before unpacking my van. On the tv was a emergency message filling and repeatedly scrolling across my tv screen: “Evacuate NOW. Oroville dam is projected to fail within the next hour. This is NOT a drill.”

Er. . . um.

The water was now flowing over the concrete “lip” of the emergency spillway (even though those-in-charge had repeatedly assured everyone that it would not do this), rapidly eroding the hillside below the emergency spillway as it flowed (no surprise to me there), and also eroding and undercutting back under the unsupported concrete lip of the emergency spillway (as of course it would). A bit more undercutting, and this concrete lip would have toppled (authorities believed this would happen, which was the reason for the evacuation order), releasing a projected 30-foot-tall wall of water down the Feather River and on into the river communities below.

I called my friends, they said "ya'all come", got back in my van, and drove the two hours back to their house. I think I went a tiny bit over the speed limit as I drove back.

I stayed with them another three days, until the worst of the crisis had passed.

Ultimately, the emergency spillway did not fail. But it was a VERY near thing.

The minute the evacuation was announced, all of the roads in the evacuation area were almost immediately either near or at total gridlock (I left for the second time the instant I saw the warning on my tv, and so avoided most of the traffic. As I drove, I could see that people all over town were still lingering to slowly pack up their cars - as I drove by, I wondered what they could possibly be thinking).

All of these 188,000 +/- people gridlocked in their cars on the local roads would have been at the mercy of the projected 30-foot wall of water, had the thing let go.

Again, it was a very near thing. Today, there are still many problems remaining at Oroville dam, which I won't get into at the moment. Suffice to say that the dam, when it was constructed, was designed and projected to last 50 years. The dam was officially "opened" on May 4, 1968. That makes it about 53 years old. And counting. . .

Thanks for your post, Sue.

It really brought the individual memories back into sharper focus.

It is an experience I will never forget.

Anne

[JudyJB]

Beth and Anne--Ditto for desert towns that were once touted as being very healthy for people with allergies because there were only desert plants growing there, which made them free of most pollen that caused allergies. And then everyone decided they really liked grass lawns and trees and lots of landscaping, so the towns now had lots of plants that produced pollen! Duh!

Another topic: Now that "Lake" Oroville is almost dry, this would be the perfect time to rebuild the dam to be smaller and safer, but of course that will not happen because the growers in the valley will demand "their water rights."

[MandysMom]

Judy, Lake Oroville isn't dry.....yet! And why would they build a smaller dam when all of CA is low on water storage? Those "water rights" feed our nation from the fruits, vegetables, and nuts plus dairy production. It isn't farmers demanding water, they had water before litigation took ot away. Fought long ago. Farmers were here before millions of people arrived demanding green lawns, swimming pools, and washing their driveways with an open hose! California desperately needs more water storage for droughts we are in now, certainly not less by tearing billion dollar dams down and building smaller!
Velda

[JudyJB]

The reason for building a smaller dam is that the current dam is the tallest earthen dam in the U.S. When it was overflowing, much was written about how the fact that is was so tall and built of earth made it dangerous. A cement dam with underground "overflow" or relief chambers, it was said, such as with Hoover and other cement dams would have been safer because it is less likely to be undermined.

[MandysMom]

Judy, please look up the history of Oroville Dam, as to how kong it took to build, why it was built, and what it's purpose is. The height is determined by the canyon the dam was built to close off, not just because they wanted to build the tallest. It's purpose is water storage, of which we are lacking. Recent UCDavs studies study seismology of the area under the dam, show there is very little chance any shifting would occur that would be damaging. If you tore down the dam,what would California do for water storage in the 10-20 years it would take for the project? Study was begun in the 40's on this project and it wasn't fully operational until around 1970, when last power plant came on. We will have snow and rain again and need not just Oroville but new dams for more storage. This dam was built to deliver water to farms and homes and for flood control. The farms, for example, haven't gotten more than 60% of their promised allotment in recent years. As to flood control, we, here for many years recall floods before dams were built. If the dam were shorter there is good chance ot would be overtopped by water due to tne size of the watershed it serves.
Velda

[Cudedog]

The reason for building a smaller dam is that the current dam is the tallest earthen dam in the U.S. When it was overflowing, much was written about how the fact that is was so tall and built of earth made it dangerous. A cement dam with underground "overflow" or relief chambers, it was said, such as with Hoover and other cement dams would have been safer because it is less likely to be undermined.

Judy, the Oroville Dam itself has never "overflowed". Nor is Lake Oroville "almost dry" (although it might seem so, considering the photos in the link in an above post). The main body of the lake currently stands at 632.73 feet in depth. That is still quite a considerable amount of water.

http://oroville.lakesonline.com/Level/

The problem that occurred there in 2017 was that the main (concrete) spillway broke apart, and, while DWR (Department of Water Resources) was checking on the damage, they needed to close the spillway so that they could inspect it. With the lake behind the dam continuing to fill.

The part that was overtopped was the emergency spillway, which had never before been used or tested since the dam was originally constructed some 50 years prior. The link in my earlier post, above, goes to the timeline of what went on during the Oroville debacle. I am putting it here again, so that it is easier to find:

https://projects.sfchronicle.com/2017/oroville-explainer/

Had the earthen dam itself been overtopped, it would have failed spectacularly, and been totally destroyed perhaps only within an hour or so. There would have been no saving it. And probably no saving any of the cities and towns downstream, all the way from the city of Oroville itself, to Sacramento, nearly 70 miles distant.

To see how fast an earthen dam can come apart, an example would be the Teton Dam in Idaho, which failed several years ago. Many people died in that one, too.

https://en.wikipedia.org/wiki/Teton_Dam

After 2017, over the next two years, the concrete spillway at Oroville Dam was demolished and rebuilt, at a cost of around $1.1 billion dollars. Yes, billions with a "b". With that kind of investment in the new spillway, the thought of a new dam is probably moot. Not saying that it perhaps should be rebuilt, but only that it likely won't be. There is an organization here that would like to see a rebuild.

All dams, both concrete and earthen, have the ability to release water should any dam become too full. In addition to exterior spillways, Oroville also has the ability to release water underground, in a similar way to what you describe, through the Edward Hyatt power plant, and also through a series of underground tunnels.

Also keep in mind that a concrete dam is no panacea. Here is a link to the St. Francis Dam, a concrete dam that rather spectacularly failed in Southern California early 20th century. 400 people lost their lives in that one.

And St. Francis is not the only case of a concrete dam failure.

https://en.wikipedia.org/wiki/St._Francis_Dam

St. Francis Dam, before it failed.


Anne