A typical John Fleck morning these days involves a cup of coffee (or two) and a curlup in the comfy chair as dawn creeps over my backyard while I wander the western United States looking at USGS stream gauges.

Today’s gauge-of-the-day is my friend and colleague Eric Kuhn’s, at Glenwood Springs, Colorado. It’s just downstream from the junction with the Roaring Fork. Flows of ~3,600 cubic feet per second on June 13 were the fourth lowest since gauging at that spot began in 1967.

Important to understand what this is telling us. This is the measure for the main stem of the Colorado as it flows out of the mountains over the divide from Denver. It is not what in overall basin management we think of as the “Colorado River” as a whole, which the water managers in the state of Colorado charmingly call the “big river”. At this point the “Colorado” is just one of three big tributaries – the Green, the Colorado, and the San Juan. To understand the overall health of the “big river” system, you need to look at all three. More on that tomorrow.

The driest years, in order:

2012: 2,230 cfs 2002: 2,280 cfs 1977: 2,870 cfs

Median flow for this point in the year is ~9,600.*

* There’s a slight discrepancy between the numbers reported on the USGS web site when you click on the link above, versus the numbers I’m getting downloading the USGS data and doing my own analysis directly. Dunno. YMMV.

** Code here.