Here in Colorado, most of the available water (runoff from snowmelt) is used for agriculture--about 85% I believe. When the cities cry out for more water, the farmers in marginal areas sell their water rights to the cities, which then causes the irrigated farmland to revert to its pre-colonial (i.e. pre-1900) status. That status was basically desert.

But there is quite a bit of support for the idea that areas like eastern Colorado should never have been used for agriculture in the first place. These areas are good for bison herds and native dryland grasses. That's the whole "Buffalo Commons" theory.

So here the conflict is between those who think that irrigated agriculture should be supported by putting limits on urban growth, and those who think that irrigating the desert was a dumb idea in the first place...