FARGO, N.D. - U.S. Geological Survey hydrologists Chris Laveau and Joel Galloway motored carefully across the massively sliding surface of the Red River toward the Fargo Water Works just before noon Saturday to look at a ruler fastened to a concrete wall. The level was just above 40.7 feet.
"That's what everybody's talking about," Laveau said.
But the biggest news of the day from the Red River Valley didn't come only from the ruler. It also came from a high-tech toy boat Laveau and Galloway were towing, and several other U.S. Geological Survey devices at the Fargo gauge, one of 75 in the Red River Valley.
Using electronics, chemistry and physics, the equipment measures the speed, volume and flow of the river. That information gets transmitted to the North Central River Forecast Center, where forecasters translate it into the figures residents, emergency managers and reporters look for: river crests.
"It's critical," said Steve Buan, hydrologist with the Chanhassen-based forecast center, which assesses river conditions in nine Midwestern states and a small part of Canada. "If this work weren't done, there would be no way we'd be able to predict [river] stages."
This week, Laveau and Galloway have been on the Red pulling a small orange trimaran, aboard which is a device called an "acoustic Doppler current profiler." Using pulses of sound sent to the bottom as frequently as 10 times per second, the device allows them to measure the depth and speed of the water from bank to bank.
Saturday the water was moving at 5 to 6 feet per second (about 4 miles per hour) and was 38 feet deep, where it's normally 14. It was moving at 32,900 cubic feet per second.
Even though the science isn't totally precise -- as demonstrated by last week's uncertainty over the height and timing of the Red's crest -- the technology upgrades make the river readings much more precise than they used to be when hydrologists would drop a weighted propeller-like device into the river every several feet.
