The U.S. government warned on Friday that it may impose water supply cuts on California, Arizona and Nevada to protect the Colorado River and its two main reservoirs from overuse, drought and climate change.

The U.S. Bureau of Reclamation unveiled three possible action plans: one to impose cutbacks, another to allow western states to work out a reduction plan on their own, or a third and least likely option of taking no action.

Besides protecting drinking water supplies, the proposed federal action might also preserve hydroelectric production at the country's two largest reservoirs.