Water is intensely political pretty much everywhere but rainforests, and at all levels of government. However, unless you're directly involved, you don't hear about it because it can't normally be used as a political football. Your opinion on any particular water dispute will have nothing to do with your political views or party affiliation, it's mostly a product of geographic location or industry, and no politician who happens to represent both parties wants to take sides. (And any politician who represents only one side will invariably adopt that side's position.)

(Incidentally, in the modern era, the US Supreme Court's original jurisdiction case load is made up almost entirely of states suing one another over either water rights or boundary disputes based on rivers.)

We're not quite Mad Max yet. Perhaps 80% of the country lives in an area where water is not scarce enough to prompt water table depletion or aqueduct building. "Water politics" in these areas mostly consist of bureaucratic squabbles regarding the minor expense of water treatment facilities & pipe-building, or soft-science environmental debates about erosion, fish, and effluents - things which can be reliably consigned to the higher end of Maslow's Pyramid.

About half of the remainder of the problem could be solved easily by ending this stupid obsession for English Country Manor lawns well outside a climate zone where they're viable, and prohibitions on all but drip irrigation for agriculture. These could be mostly accomplished without legislatorial nitpicking by simply making prices reflect scarcity, permanently. We seem to have an innate resistance, politically, to pricing water to reflect its infrastructural and depletion-replacement cost, to admitting that some mechanism needs to scale back use.

Some issues are simply not solveable, it's true - isolated water tables that have been changed by taprooted invasives are probably never going to revert to grassland, and need total cessation of irrigation activities to avoid desertification. These cases are relatively rare though.

I've read that when California's major water systems were built long ago there were explicit compacts between the urban and agricultural regions. The latter now see various actions as breaking that.