Interestingly, the natural state of much of California was a swamp. We put in a lot of effort converting the swamp to desert.
If we reestablished the swamps, California would be a much less pleasant place to live, but it might be a better place to grow stuff like rice.
[1] You're using "Northern California" and "Southern California" differently from everyone else; in normal use, Northern California is the Bay Area, not the north of the state.
No, norcal is north of LA, not just the bay area. I’ve never heard of anybody referring to the bay area as norcal, it’s always “bay area”
But my point is that the region to the north of, say, Berkeley, is not part of "Northern California". It's too far north for that.
We consider ourselves part of Northern California and have since at least the 70s. For many up there, the Bay Area is only nominally part of Northern California, in fact as a kid I didn’t think it was. But having gone on to live in San Francisco for a long time, I came to realize that the the Bay Area, for better or for worse, has more in common with Redding then it does with Manhattan Beach.
But I can’t figure out what you think the too-northern Northern Californians should call themselves if they let you lop off the Bay Area (and most would thank you for it).
Anyways, they do use in freshwater differently. Where I grew up in NW Ohio, there is practically no irrigation. It rains enough there’s no need. Freshwater use is passive, in other words. Out west, farms have to actively pump water to irrigate since there’s not enough rain. They can control how much freshwater they take out of the water source in a way the Midwest farmer can’t.