A new study shows that cannabis cultivation accounts for just a small fraction of the Northern California water demands. Scientists studied 14 watersheds that drain across 14 counties and concluded that cannabis farming only accounted for about 1.6 percent of water use, while residential use and non-cannabis farming used significantly more. The study suggests planners treat all users as one group, rather than singling out cannabis operations when forecasting dry season diversions. Licensed cannabis farms are prohibited from diverting during the dry season.