The Moving Delta

For approximately 40 years the Colorado river slowed down in Cataract Canyon and dropped its sediment load when it reached the calmer waters. This resulted in a reservoir-caused “delta” made up of the sediments that should have been beaches and river bed load moving downstream. Instead, those sediments buried the lower parts of Cataract Canyon.

Flooding Glen, Narrow, and Cataract Canyons with water to make Lake Powell was highly controversial. There is another, quieter, issue creeping into these canyons - the mud, silt, and river delta slowly filling the canyons as the river sediment drops out into the reservoir.