The alternative to an hydraulic tyranny is to RELOCATE to somewhere else where it rains.
Ancient Hydraulic Tyrannies occurred along the Euphrates, Nile, Indus, Ganges, Huang Ho, Yangtze, etc. and around the lake in which ancient Mexico city nestled (for example).
It's fairly certain the leaders in Terre Haute were well on their way to the same political system inasmuch as they'd figured out how to build large fish lagoons and pens to thereby augment the protein needs of the community. The earthen dams that made the fish lagoons possible are still there ~ there are some in/near Evansville, Indiana and probably around and or near Cahokia (more digging needed to find the soil changes that accompany fish pens though).
The United States, in the aggregate, is able to avoid becoming an hydraulic tyranny simply because people are free to move, and they also vote. That does not mean you can just willy nilly divert water to your own personal use in arid and semi-arid regions. What happens if you allow that sort of behavior is a single individual becomes the tyrant with the power of life and death over his neighbors.
Where it rains sufficiently this is not a real risk. Where it doesn't rain sufficiently that risk is there all the time.
Oregon is not Arid. Note even semi-arid, more like sopping wet drying down to humid.