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Wednesday, October 21, 2009

Water Control

There's water under the Devil's Gate dam again. We were told that last week's rain wasn't much and truly it's only a stream, but it's good to see.

Click on over to the Pasadena PIO's recent Mystery History piece about the dam and scroll down to the well-known photo of the "completed project." The dam is no longer a public road, but that square control tower or guard house is still there. From where I was standing when I took this shot, all the water in the PIO's photo would have been behind me, where this is now.

The dam was built back in the days when there was enough water that it needed controlling. We don't have that problem now.

I check in at LA Creek Freak a lot. I don't comment much because I don't know what to say. But they do, and they're worth reading.

17 comments:

Cafe Pasadena said...

Thanks, P. Now I know why you don't comment much. All this time I thought it was because you were busier than a shutterbug.

J+P said...

Shot gives me the vertigoo

Shell Sherree said...

That is good to see, and hopefully there's more where that came from!

altadenahiker said...

Oh, but don't you remember out big storm a few years back? Crowds gathered on the bridge (I was among them) to watch and feel the water surging by. It wasn't just a stream that time.

Bellis said...

That huge waterfall a few years ago was quite a spectacle! But this time, I couldn't understand why they let the water go to waste like this - once it's gone through Devil's Gate dam, it flows straight to the ocean in a concrete channel (bar two small gaps) and all that precious fresh water is lost. Why wasn't it diverted to the sinking ponds in Hahamongna and stored below ground? If anyone knows how the Arroyo Seco water is managed, I'd love to hear from them. I'm sure the water folks know what they're doing!

Petrea said...

I think that big storm was spring of 2005, am I right? I wasn't living here then, but I heard of it. To me four years is a long time to go without enough rain. We've seen water behind the dam--we see it each spring. But I've never seen it up that high.

Bellis, they can stop the water at the Parker Mayberry Bridge (under the Colorado Street Bridge). But did they? I don't know.

J+P said...

A veritable cataract—or do I need new a new spectacle?

Greg Sweet said...

That's a "control house" and a "gauging station".

My friend Darryl invited me to the control house at Santa Anita Dam on the night of January 8th - 9th, 2005. That was the height of the big "Pineapple Express" storm. He can monitor by computer what all the other dams are doing. Devil's Gate was getting an "inflow" of around 2,500 cubic feet per second. For comparison, Santa Anita was getting 1,300cf/s; Cogswell Dam north-east of Mt Wilson was getting 4,000cf/s; and the big San Gabriel Dam in Azusa Canyon was getting 25,000cf/s! I know the figures went up after I left at 1 or 2 am - the storm peaked around 3 am. That is just way to much water at once to save, and in fact, if the dams have water going over the spillways, it means that they cannot hold any more water.

Our dams are mostly for flood control, not for water use. A big problem they are having is that most are getting filled with debris, which reduces the volume needed for flood events. But digging out just one dam is a major (and expensive) event. There are ecological concerns in the wildlands where the dams are located, plus where do you put the debris? and what subsequent environment will it affect. Also, nobody wants the dirt in their neighborhood. I think they should truck the debris to a barge and dump it in the ocean, where Mother Nature was sending it anyway.

Petrea said...

Thanks for the insights, Greg. I don't know about dumping in the ocean, though. Some of the debris is logs, grasses, natural stuff. But a lot of it is plastic and trash.

I have some photos of last spring's debris at Devil's Gate. I'll see if I can put together a chronology of the debris collection for tomorrow.

Bellis said...

Greg, the Hahamongna sinking basins are not debris basins, but maybe there was too much debris and ash coming down from the burn areas for the water to be stored? The dam under the Colorado Street Bridge didn't hold back any water, as the channel downstream of it was pretty full - but only on the day AFTER it stopped raining. Does it take that long for the water to come out of the mountains? Wow.Here's a good chart: http://tinyurl.com/yj22my9

Desiree said...

kewl! And, your readers are so, hum

eau courant!
(translation: up on their water)

altadenahiker said...

Eau yes, Dez is so right. I'm following this -- I want to know -- do we save rainwater, can we save it? I've often heard nothing matters but the snowpack.

Margaret said...

Having seen PIO's post, this is really timely - and interesting.

Petrea said...

It took me this long to get J's cataract/spectacle pun.

Interesting stuff, Bellis. I wish I knew.

More questions than answers, but Des is right, eau courant, you people. Merci.

acai berry said...

Preventive measures are taken for water control as There was not much last week. It is good to see the dam build on the public road.

Joe said...

Creek Freaks happy to hear you're listening to us and praising us here. We'll work to keep inspiring you as much as we can.

Petrea said...

Thank you, Joe. I often link to LA Creek Freak.