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Thursday, October 22, 2009

Debris at the PWP Corral

In yesterday's comments the Altadena Hiker reminded us of the high waters behind the Devil's Gate Dam after a storm in spring of 2005. Greg Sweet wrote of the debris that builds up behind our local dams after big storms. That gave me the idea to post these pictures from spring of 2008 to show what Pasadena Water and Power does with storm debris behind Devil's Gate Dam.

In the first two photos you can see JPL in the background. I didn't know what the line of connected logs was for at first.

But as the water recedes it becomes clear that the logs are in place to corral the debris that has gathered in the flood.

A lot of the debris is twigs and logs. But if you enlarge this photo you can also see plastic bags, styrofoam cups, a flashlight and a lot of unidentifiable stuff. If the water gets high enough, plastic bags and all sorts of weird junk hangs in the trees.

Sprocket and Boz find it absolutely delightful.

I'd say the PWP does a fine job. But I have no idea where they put it all.

14 comments:

Anil P said...

Bio-degradable debris is not so much of worry as is the plastic kind.

This must entail good, hard manual labour once the storm has blown away.

Turquoise Diaries said...

Very dramatic pictures. We need water and have to take every necessary action to save it

Petrea said...

Hi Anil, welcome. I think you're right. They must have brought in trucks and loaded them up. There's a city dump not far away. We have a recycling program here, so they might have taken it all there to be separated. I hope so.

Aysegul, the Devil's Gate Dam forms the southern border of Hahamongna Watershed Park. The word "watershed" in the park's name describes a series of basins there designed for directing water. I have more pictures of them I can post this week if people want to see them.

Bellis said...

What a fantastic series of pictures! I think I've finally worked out what the two obelisks are for, but I'd have to wait for the dam to fill up again to see if I'm right.

Greg Sweet said...

Be careful taking photos out there. An old timer once told me of a boy that was lost to quicksand behind Devil's Gate Dam in the 1950's.

I know quicksand occurs here because I got caught in some myself. I went to take some dirt that had washed down onto the Chantry Flat Road. It was only about a foot of soggy decomposed granite sitting on top of the asphalt, but I really got stuck!

I happened to have a cheap camera in my pocket and I took some bad video of myself trying to get free. It nearly ripped the boots off my feet with each step...
http://www.youtube.com/watch?v=pJ3QprjpKNM

Linda Dove said...

Really interesting photos. That phenomenom of plastic bags in trees is apparently known as "Los Angeles moss." Happens all the time in the L.A. River. I put it in a poem. ;-)

marley said...

Amazing difference. Great photos.

altadenahiker said...

I love this collection of photos, taken over -- what period of time?

(My horse and I were almost lost to the quicksand. That's the time she fell backward on my hand and broke it.

Bellis said...

Inspired title, by the way! I'll always think of it when I walk past there now.

Petrea said...

Bellis, don't keep us in suspense. The obelisks must be for measuring water depth, don't you think?

I see your car got stuck too, Greg. Bummer. Boz and I have seen some freaky mud down by the dam. Good thing he only weights 65 pounds.

I'd like to see that poem, Linda. Is it in the new book? I'm not sure Los Angeles Moss is an object I'd defend...

Howdy Marley, thanks.

Where were you riding, Karin? Not near JPL, I hope. I moved the original photos to a file on my desktop and the information about when they were taken is gone. I know some were taken in May of 2008 but I can't tell you the time span for sure. What do you think? February to May? I remember the debris was there a long time because it had to dry out. I don't remember how long the water was there, but it's always wonderful to have it.

(Hate is a strong word, but I seriously dislike iPhoto. I should stop complaining and buy Photoshop but I keep hoping someone will show up and tell me there's decent software out there for us poor folk.)

Bellis said...

The duckboard walkway is attached to the metal poles next to the obelisks, and as the water level rises, the walkway floats up. But could anyone, apart from ducks, walk across it when it's floating like that? Come to think of it, you must be right, Petrea, the duckboards show the height of the water.

Petrea said...

I never knew they were called "duckboards," Bellis. I also never noticed them rising on the water. I don't think I'd walk on them. But if they hold a person's weight and measure water height, they'd still serve a third purpose of getting a worker out over the dam, as I think you're indicating. You have a wily brain.

Mike said...

In the early 70s I used to go to summer camp there (Tom Sawyer Camp) I must have explored every inch of the place. I don't recall seeing too much refuse there.

In those days, there were few trees in that area shown. There was a very small clump in the middle, and some brush, but it wasn't the way it is now. There were tons of toads out there. I mean millions. There were huge frogs as well, in the water.

The rest of the area all the way up to JPL largely consisted of sand dunes. I suppose it's still that way. There also was a stream up there, near JPL, which I assume is still there.

We used to ride horseback there (no saddles, nor helmets) a lot, but I'm sure that nowadays they don't let the kids ride at full gallop or up and down hills like we did.

As to the boy who disappeared in the 50s, Greg Sweet may be referring to a boy whose disappearance has only recently been solved. Sad story - http://www.arroyoseco.org/newsfull.php?artic=690

It'll be nice to see more pics.

Petrea said...

Mike, I've seen the toad phenomenon--millions of tiny little things jumping. Boz (my dog) was thrilled. We saw them two years ago but not last year. I think they need more water.

The stream is still there. It runs heavier in the spring. The sand is in the center of the park. I wouldn't have called it dunes because there's so much vegetation. The eastern part of the park is the watershed basins, dirt and trails.

It hadn't occurred to me that Greg might be referring to the case you mentioned. "An old-timer" might tell the story that way, as the boy's disappearance must have seemed inexplicable at the time. I featured Weston DeWalt here on PDP right about this time last year.