Looking south down the Rio Grande from the Paseo del Norte Bridge in Albuquerque Sunday, Sept. 23, 2007.
That’s maybe 450 cubic feet per second of flow, which is getting down toward what they call “base flow“. That’s the minimum flow in a desert river, the point at which you’re really just seeing the water table moving downstream rather than runoff. Not sure how close we actually are to it here, because they still seem to be letting water through the dams upstream, but we can’t be far above base flow right now. The river rarely gets lower than this.
It’s that autumn moment when we’re gathering and taking stock. The irrigation season is all but done, there’s no new water coming into the system and not much going out. The plants aren’t quite shut down, but evapotranspiration is on the wane, and the first yellow-brown leaves are showing on the cottonwoods. If we could see inside the trees, we’d no doubt find the soft light colored wood slowing as they prepare to put on the hard dark thin ring of winter. There’s no snow on the mountains yet, but soon we’ll be looking north and monitoring the growing snowpack and starting to wonder about next year. A sort of climatological, ecological, sociological pivot point in a place where things revolve around the water.