california water dating back to over a century ago are also facing restrictions for the first time since 1977. as the mayor of california's largest city told me, examining water usage will help offset the crisis. >> we've added in the last 45 years a million residents without having to consume a single drop of water more. so it's changing -- it's true. we have 3 million to 4 million more people in last 45 years and we consume the same amount of water as back then because so much water is wasted. >> reporter: some are looking at the very industry that uses up so much of the state's dwindling resource. >> half of california's farms still use the antiquated flood and furrow techniques where you literally lip up the loose gates and let the water flood your warm. >> you used to use flood irrigation. explain the difference. >> flood irrigation goes on top of the surface and have you no