>> i'm standing in front of peter's canyon reservoir and that dusty patch of white behind me is where the water should be. with reservoirs running dry, farmers are turning to groundwater. over time, groundwater accumulates in vast underground aquifers. but no you, over the past few years, groundwater levels have dropped 50 feet or more as farmers drill deeper and deeper to access it. >> today we do set in law a framework that has been resisted for long, long time. since before my father was even governor. >> reporter: just last year, california became the last state in the west to regulate groundwater usage. the state's first-ever mandatory water restrictions soon followed. >> we're in an historic drought, and that demands unprecedented action. >> reporter: a 25% reduction in water usage state wide has forced residents and businesses to cut back. farmers with rights to california water dating back to over a century ago are also