If you are following the news out west, you know that Lakes Mead and Powell are at low levels not seen since the reservoirs were filling up. Now, after years of drought and overuse of water, they are running out of water. Here is a good historical perspective from Colorado Assistant State Climatologist Becky Bolinger on why they were doomed to fail from the beginning. It is related to a misunderstanding about the climatology of the basin and how much water they could reasonably expect to get each year. You can read it in the Washington Post.

Source: Commons Wikimedia