A hundred years ago, the U.S. Geological Survey installed one of the nation’s early stream gauging stations on the Colorado River at the head of the Grand Canyon.
In 1921, a concrete tower was built at the base of an old dugway road at Lee’s Ferry. Today, thousands of boaters and anglers see it from the nearby launch ramp. A cableway stretches across the river to the structure, giving access to instruments that record key data on the water’s velocity and height.
E.C. La Rue, a hydraulic engineer with the USGS, personally saw that the gauge was established. He was also pushing for a tall dam a few miles upstream. His preferred site wasn’t chosen, but Glen Canyon Dam would later be built 15 miles upriver.
Meanwhile, the stream gauge went into service just as the Colorado River Compact was being negotiated among the seven states in the river’s basin. Lee’s Ferry was set as the division point between the upper and lower basins. So the measurements of the Colorado’s flow at the gauge were essential to meeting the compact’s obligations.
But water projections in the 1922 agreement were overly optimistic. As a megadrought grips the Southwest, the fate of Glen Canyon Dam and shrinking reservoirs is front and center in discussions about how the river can meet all the demands.
And the historic Lee’s Ferry gauge, with updated equipment that transmits information hourly, is even more critical to decisions that affect the Colorado River, and the millions of people who use it.
This Earth Note was written by Rose Houk and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
