Downriver

This seemed strange at first glance — although as an “Easterner,” I do get a bit prickly when Westerners (as in Texas) call creeks (or worse yet, dry beds) “rivers” and boast about “lakes” that you can easily holler across.

I spent my early years back East, in what an Easterner might call the land of “real rivers.” French Creek, which joins the Allegheny River in my Pennsylvania hometown, is about as big on average as the Colorado River gets in Colorado; and the Allegheny River, at its junction with the Monongahela to create the Ohio River — still more than a thousand miles from the ocean — runs as much water on average as the entire Colorado river.

(George Sibley, “Does a River care if it doesn’t get to the Ocean?”, Mountain Gazette, May 2008, p. 26)

However, it’s true. The average flow of the Colorado, over the past 300 years, has been around 13.5 million acre-feet, or 18,630 cfs (1 acre-foot/year [AFA] = 0.00138 cfs). The Allegheny, at Pittsburgh, has a mean discharge of 20,000 cubic feet per second (cfs). The Mississippi surpasses the Colorado’s flow at about Red Wing (below L&D 3), within its home state of Minnesota — over 1,700 miles from the sea.

Now, that’s not a small river by any means — the Allegheny is 800′ wide at the Ft. Duquesne Bridge, and the spring flow over mighty St. Anthony Falls in Minneapolis is just 10,000 cfs — but 25 million Americans depend on Colorado River water. In a final irony, the Colorado/Great Basin will likely see flows drop by over 10% over the next generation, while the Ohio basin could see flows increase by over 10%.

Yet we in the Great Lakes are truly spoiled. The “Chicago diversion” draws 2.4 billion gallons from Lake Michigan every day, dumping all of it down the Mississippi (via the Chicago and Illinois rivers). That’s 2,688,240 acre-feet, close to the 2.8 maf that the entire state of Arizona receives under the Colorado River Compact.

Advertisements