Agreed the approach resulted in higher food production for many decades. But diverting water means diverting it from filling up lakes or going into the ocean- both of which devastated the fishing industry. And the diversion from the ocean now threatens agriculture itself- the salinity of the water in the river delta is increasing. Diversion for agriculture also means diverting it from aquifers- it remains to be seen what will happen to agriculture if the wells end up dry. Maybe the system was working before climate change. But now we have to wonder if the ability to export almonds to China is worth not having the largest freshwater lake of the western US. There was probably a middle ground where California could have one good wet season for agriculture and one season for dry weather crops rather than growing whatever we feel like all year round.