AERIAL PHOTO; AP PROVIDES ACCESS TO THIS PUBLICLY DISTRIBUTED HANDOUT PHOTO PROVIDED BY JOSH F.W. COOK/BUTTE COUNTY SHERIFF/ASSEMBLYMAN BRIAN DAHLE
This Friday, Feb. 10, 2017 image from video provided by the office of Assemblyman Brian Dahle shows water flowing over an emergency spillway of the Oroville Dam in Oroville, Calif., during a helicopter tour by the Butte County Sheriff's office. About 150 miles northeast of San Francisco, Lake Oroville is one of California???s largest man-made lakes, and the 770-foot-tall Oroville Dam is the nation's tallest. (Josh F.W. Cook/Office of Assemblyman Brian Dahle via AP)