The question of who has a right to the water extends back much further than your relatives arriving and upsetting the rightful owners. They had their own water rights laws and customs.
Everybody on Earth follows some sort of standard ~ in the United States we follow BOTH the big ones. That's cause were' HUGE.
"The question of who has a right to the water extends back much further than your relatives arriving and upsetting the rightful owners."
The tyranny may or may not. Getting a high population density of cornered 'rats who empower heavily bunkered, unelected bureaucrats causes all sorts of problems.