California will not be able to take Arizona’s unused water in Lake Mead. That was the take home message in a letter from a federal water official to Sen. Jeff Flake on Wednesday. As the drought on the Colorado River has lingered on, Arizona has voluntarily foregone some of its water and left it in Lake Mead instead. By 2017, that will total more than 300,000 acre feet. The goal is to keep enough water in the reservoir to stave off much more severe cutbacks for Arizona in the next year or so.