Water in the Desert

Rio Grande at Alameda

Originally uploaded by heinemanfleck.

We’ve had a burst of warm weather over the last two weeks, and you can see it in the river. Up at Alameda, it’s running at about 1,700 cubic feet per second (cfs) well above the average of 1,100 for this time of year. I realize for people who live with real rivers this might not seem like much water (the Mississippi is currently flowing at 271,000 cfs past St. Louis), but you live in the desert with the river you’ve got, not the river you might want or wish to have at a later time.

This picture is taken from the Alameda Bridge, and I’ve picked a spot I can find and return to ever time I’m up there, lining up the camera on the bridge railing so I can capture the change over time. You can see the cottonwoods – the large trees on the bank to the right – aren’t close to leafing out yet. What looks like the left bank in this picture is actually a sandbar island in the middle of the stream. Before the river was hemmed in by levees and controlled by Cochiti Dam upstream, islands like this did not exist. Rather than one central channel like we have now, the river was braided and meandering – far more shallow, far wider, with patches of cottonwoods, marshy wetlands, and bare sandbars scraped clean by the spring flood every year.

With no high spring flood, the sandbar islands have become “armored” with plants, mostly willows. Up at the head of this island, though, the Interstate Stream Commission has been doing some terraforming, scraping off the brush and scraping down the sandbar a bit so the island can be easily overtopped with water. That creates habitat for the endangered Rio Grande silvery minnow, which used to spawn in the slow-moving meandering braids. From the bridge, it looks like the overtopping is already happening at 1,700 cfs, which is exciting to see. There were geese today flopping around in the shallows created by the ISC project.

One Comment

  1. I trust the locals there eradicate the tamarisk and other nasties that ‘armor’ the ephemeral islands too, John…



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