They literally constitutionally cannot ask the farmers, and you need a very mobilized populace to change the constitution. That's only going to happen when people see the consequences of inaction, and its probably better that happen gradually for useless laws then suddenly for all drinking water.
That's not the only way ballot measures and propositions have been passed. Previous governors have advocated for measures, got them on the ballot, and encouraged people to vote for them. The current governor could do the same.
