April 26, 2023 — The Bureau of Reclamation has initiated a high flow experiment to rejuvenate sand dunes along sections of the Colorado River near the Grand Canyon. Water was released from the Glen Canyon Dam at four to five times the standard rate, causing a 72-hour flood of the river before returning to regular flow.

The experiment aims to transport sediment from the Paria River to beaches and sandbars in Marble Canyon and the eastern Grand Canyon, restoring the Colorado River corridor within the eastern Grand Canyon National Park. Lake Powell’s water level will decrease by approximately 4.5 feet, while Lake Mead’s level will rise by around 4 feet by the end of May. However, Lake Mead’s total water intake will remain consistent with the previous year.

The release is designed to create more camping-friendly sandbars and supply sand to protect archaeological sites in the eastern Grand Canyon. Officials deemed the hydrological conditions and high sediment loads suitable for the release, marking the first such experiment since November 2018.

During the experiment, some riverside campsites may be unreachable due to elevated water levels. National Park Service officials have cautioned river users about potential changes in the river’s behavior around rapids. The Bureau of Reclamation will reduce the outflow tomorrow morning, with river flows expected to return to normal levels by tomorrow night.