Just to throw it out there, there are alterative types of agriculture such as ultra-local production, aeroponics, hydroponics, vertical farming, etc. that _could_ be significantly less resource intensive if executed correctly on a large scale.

I'm not saying that I am sure they will use less water but we could try and if we focus on being efficient with electricity and land it could make a big difference. For example aeroponics doesn't have to use artificial lighting.