What’s the name of this thing?
I’ve seen it in many movies and half the time they are racing cars down the thing. (Repo Man, To Live & Die in L.A. and T2 I think)
It looks like some sort of concrete waterway that is all but drained.
What is it? Is it ever supposed to be full of water? Do people really drive down there often? What the hell is that thing called?
This is a stormwater channel. While it’s usually dry, some also have a narrow section with anywhere from a trickle to a large stream during dry weather (base flow).
Because most of the city’s area is paved or otherwise impervious to stormwater, the water level can rise very quickly during a rainstorm. In the trade, we call this rapid rise in a stream or river “flashiness”.
When these cities were built up, the idea was to get rid of this stormwater as quickly as possible- hence the large concrete channels. At maximum capacity (bankfull flow) they are a sight to behold as well as incredibly dangerous.
Of course, these channels offer very little in terms of habitat for wildlife and present day engineers try to accomodate stormwater with natural stream channel design. But as long as a certain percentage of the watershed is composed of impervious surface, there is only so much you can do in terms of a natural design
The Los Angeles River. No, I’m not kidding. The natural river bed is completley lined with concrete and AFAIK only has a significant amount of water in it when it functions as a storm drain.
The Los Angeles River was paved so it wouldn’t cut a new channel each time it filled up during the winter rains.
There have been numerous ideas about revitalizing the river. Some want to restore it to its natural state and others actually wanted to make it in to a freeway.
I heard Andy Reese (stormwater guru) declare that Los Angeles County averaged 17 drowning depths per year in the aqueduct/river system. :eek:
Do people really drive their cars down there or is that only a movie thing?
It’s a movie thing. They’re usually fenced up pretty tight making access to them difficult unless you’re willing to bust through the gate. Plus, based on the condition of the one two blocks from me, they would be too muddy, slimy and otherwise clogged up to obtain any decent speed.
To emphasize what’s been said above, Los Angeles and adjoining Orange County are several thousand square miles of mostly insoluble surface area. Even half an inch of rain can generate an amazing volume of water which must be shunted to the ocean through these waterways. When it does rain, these drains get very full.
Switching from fact to speculation, it might be possible to ride a motorcycle down there but, again, the occasional slippery patch would make it extraordinarily dangerous.
I thought I heard on NPR a couple/few years ago that the underground water resources of the Los Angeles area were threatened because A) the whole place is paved, and B) the “rivers” shoot the water straight out to the ocean. IIRC, the water would percolate down from the flat surface to replenish the water table. People who built their houses in the flood plain thought it was bloody inconsiderate of the rain to flood them every year, so they had the Army Corps of Engineers pave the river beds in the 1920s and 1930s.
Am I remembering correctly? (No time to search at the moment.)
After big rains in 1933 and 1934, engineers started paving the Los Angeles River channel in 1938.
About 40% of the river is paved.
17 drowning deaths per year in the river seems like a very high total, unless they are mainly suicides.
Seemed high to me too at the time. This guy was speaking at a stormwater seminar in Nashville. He indicated that some victims did not understand the dangers of the canals, and that others were non-swimmers who went swimming anyway. He did say average so maybe if there were one year with a flood and lots of drowning deaths it skewed it. Or maybe my ears were full of wax and he said “seven” instead of “seventeen”. 
I apologize for bringing up something not-so-substantiatable in GQ.
I’m not finding any good statistics that specifically answer this question.
This page, http://www.colorado.edu/hazards/dr/dr349.html, talks about a particularly fierce storm in 1980 that led to
This page (warning, PDF file), http://www.lacofd.org/CRO/Safety_handouts/Pool_Safety_Checklist.pdf, says
[QUOTE]
[ul][li]121 drowning incidents occurred [in Los Angeles County] in 2000.[/li][li]Of those 121 drowning incidents, 22 of those resulted in death.75 percent of all drowning deaths occur in the backyard pool, spa or bathtubs.[/ul][/li][/QUOTE]
It sounds like the the aqueduct/river system in Los Angeles county may have been extremely dangerous 25 years ago, but that these days it’s the pools and tubs that are the big killers.
I only thought that the number was high because when it does rain here in Southern California it is a big news event and all the TV stations go on “Stormwatch” and reporters stand in raincoats over by a hillside in Malibu to see if it will give way, another stands over a freeway and the helicopters usually are flying over either the Los Angeles River or the Rio Hondo to see if anyone fell in.
I do know that people do drown in the LA River or other storm channels. When it rains, they do get full and the water is usually moving at a very fast speed.
The Arroyo Seco, which goes through Pasadena, also cuts through a golf course. And no matter what the weather is, you are not allowed to fetch your golf ball out of the river bed.