April 17, 2009 § 4 Comments
I am in the midst of a depressing exercise of stream deletion, viz. the image at right. Once again, mapping streams of LA, and then deleting them to be able to say with some reliability what’s left. It’s painstaking as well as simply painful.
While simultaneously reaching for some (legal) numbing agent and zooming in a former stream on the north slope of the Hollywood Hills on GoogleEarth, however, I noticed urban runoff dribbling down the gutter. I was looking for any chance that a stream channel persisted (further down the road, there was in fact an open semi-channelized waterway – so it wasn’t entirely empty hope). Curious, I followed the runoff upstream, till I arrived at what was clearly a stream. And it is pretty apparent that the runoff is coming from the stream. The next canyon over showed a similar pattern of runoff. And it was in the month of July, so not seasonal, this.
I often find myself wondering during conversations about “urban runoff” how much of it is genuinely from some idiot watering his or her driveway. True, we have no shortage of waste from poor water management, and plenty of it is polluted.
But here is interesting evidence that some runoff is from a stream just being a stream – and that it would still be flowing in a stream if we hadn’t rammed a street through it. Suggestive to me, anyway, that we might want to have a policy for managing this urban runoff a little differently than treating it like wastewater.
Great stuff, Jessica.
This really illustrates what so many people (resource managers included) in LA have forgotten — the wide distribution of springs feeding streams across the basin. The shifting baseline has wiped it from the collective memory, but the capacity is still there if it can be recognized and restored.
It seems we need a water budget for our basin. I think the City of LA should come up with one for Ballona Creek watershed for starters, as part of their TMDL planning. How can they know which storm drains they need to focus on cleaning up if they don’t know how much of this relatively clean water is coming down from the hills?
Thanks for the great post.
[…] stream mapping is complete, but that image of a stream’s flow spilling over and down a road stays with […]
I’ve seen little streams like that flowing onto roads in the Hollywood Hills also! Unfortunately I don’t remember where they all are.