Water rights are constantly under threat. The western states take it very, very, very, very, seriously. In the Rocky Mountain states, the only water available is what falls on it, either today or in the past. Water rights are usually assigned and transferred with the land , and so they are part of the real estate. This is also the only real way water rights can be protected from thieves in government and environmentalists. The constitution still requires compensation for eminent domain taking of land, and the government would have to compensate landowners for taking their water rights.
For now.
There have already been plans bubbling up in the Obama administration to "reform" water rights and to transfer water rights to the people that "need it". This must be fought hard and people must be educated as well, because not enough people understand the massive private property grab that would occur.
In a little town near me, a municipal water system was recently put in due to a gas pipeline break years ago. Now there are a few families being sued because they refuse to destroy their wells. (Not cap, destroy)
The people don’t want to pay for wash water and lawn water etc but do accept the city water for drinking.