Earth Notes: Lava Falls Flood
A hundred years ago, before big dams constrained the Colorado River, boating was exciting and far less predictable.
The Birdseye Expedition of 1923 experienced such excitement at Lava Falls--the monstrous class 10 rapid on the Colorado in Grand Canyon. Claude Birdseye and his 11 men were the first U.S. Geological Survey crew in the Canyon, and they made significant measurements along the river and mapped a slew of potential damsites.
The expedition arrived at Lava Falls on September 17, just as the river went on a rampage. Light rain and thunderstorms had passed through, but they were unaware of a major monsoon storm far up in the Little Colorado River basin. The river was flowing at just over 9,000 cubic feet a second.
On September 18, it had quadrupled. Birdseye reported “the river commenced to rise and continued to rise all night.” And a sleepless night it was as the crew had to keep lugging the 800-pound boats to higher ground to avoid the rising water. That morning they watched huge driftwood logs float by in the mud-choked river, while the rapid itself had completely changed.
At the flood’s peak, the Colorado rose 20 feet and reached more than 98,000 cubic feet a second, ten times what it had been two days earlier.
Birdseye and his men waited a couple more days before deciding it was safe to proceed downstream. They had witnessed one for the record books, and left us with a reminder of just how truly wild the Colorado River was a century ago.
This Earth Note was written by Rose Houk and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.