Before the dam was built to store drinking water and harness electricity for western states, the silt-laden Colorado River flowed high through the Grand Canyon creating beaches and habitats. Sediment is now blocked behind the dam.
Up until recently the federal government rarely allowed operators to release water and conduct high flows. But last year the Obama Administration called for more frequent controlled floods.
Matt Kaplinski, a geomorphologist at Northern Arizona University, said it’s too soon to say whether the floods restore the canyon downstream but the flows need to happen consistently to find out.
“The hope is that the continuous release of these restoring high floods to the canyon will result in a long term reversal of that trend of exporting sediment from the system,” Kaplinski says.
But anytime dam operators bypass the power generators electricity providers lose revenue. Leslie James is the executive director of the Colorado River Energy Distributors Association, a coalition of western power companies. She said a series of high flows could eventually lead to replacing the cheaper hydroelectric power with more costly power from other sources.
“When you need to move water from one month to another into the month of November to produce that high of a flow, given the reservoir conditions today, you’re taking water out of other months,” James says.
Depending on sediment upstream of the dam, the next high flow will occur in the spring.