The Colorado River used to flow at that rate as a routine. I vividly remember working at the Grand Canyon (El Tovar Hotel) in 1958, and hiking down the the bottom of the Canyon. The river was a powerful thing back then, before it was dammed upstream.
That was one of the best jobs I had. I only earned 65 cents per hour (plus board and room), but I got to keep all of my tips (I was a bus boy). My mother took my paycheck, but I hid the tips.