The first appellate court to consider a case regarding California’s curtailments of senior water rights held that the State Water Resources Control Board (“State Water Board” or “Board”) lacked authority under Water Code section 1052(a) to curtail pre-1914 water rights based on the unavailability of water for use under such rights. The curtailment cases began in 2015, in the middle of a multi-year drought, when the State Water Board curtailed the exercise of many water rights across the state in an effort to implement the priority system arising from California’s water laws.