美國內政部長坎培松（Dirk Kempthorne）3月5日拉開格蘭峽谷水庫（Glen Canyon Dam）的閘門進行洩洪，開始為期60個小時的『高流量水流測試』。由此造成的洪水水流預期可以將沙子推到河道的底部，並沿著河道形成一連串的沙洲和沙灘，使被阻擋在水庫內的沉積物能重新注滿河流。
這個測試是由美國地質調查所（U.S. Geological Survey, USGS）、負責科羅拉多河格蘭峽谷水庫運作的美國開墾局（Bureau of Reclamation）、以及管理大峽谷國家公園的國家公園管理局（National Park Service）等3個內政部機關所共同主導進行的跨部會研究。
More than 300,000 gallons of water per second is now gushing through the Grand Canyon, released from Lake Powell near the Arizona-Utah border in an effort to restore sandbars needed by native plants and fish.
Interior Secretary Dirk Kempthorne Wednesday pulled a lever at Glen Canyon Dam to release the water for a 60-hour "high flow test." The flood of water is expected to push sand built up at the bottom of the river's channel into a series of sandbars and camping beaches along the river, replenishing the sediment that has been held back behind the dam.
"The water will be released at a rate that would fill the Empire State Building within 20 minutes," Kempthorne said. "It will transport enough sediment to cover a football field 100 feet deep with silt and sand."
The experiment is an inter-agency research effort conducted by three Department of the Interior bureaus ?the U.S. Geological Survey, USGS; the Bureau of Reclamation, which operates Glen Canyon Dam on the Colorado River; and the National Park Service, which manages Grand Canyon National Park.
High flows also create areas of low-velocity flow, or backwaters, used by young native fishes, particularly endangered humpback chub, one of four remaining native fish in the Grand Canyon.
USGS scientists will be monitoring how the high-flow releases affect the survival of a population of young humpback chub.
Researchers will collect data on the changes in sandbars before, during, and after the high flow. This data will be used to improve the predictive capabilities of the existing sediment model and determine the optimal peak flows of future high-flow experiments.
But a conflict over future high-flow experiments has caused a rift within the Department of the Interior.
The fight pits the U.S. Bureau of Reclamation, which is pushing a plan supported by water and power interests, against the National Park Service which says the plan will harm wildlife and habitat in Grand Canyon National Park, according to a national organization of government employees in natural resource agencies.
Public Employees for Environmental Responsibility, PEER, released documents last week that illuminate the intra-agency conflict.