The land and any associated rights was taken from the Native Americans by coercive force. Not a market. Not that they have any particular claim to it; states own land, not ethnicities. The particular state that controls land sometimes changes. This has little to do with any discussion of water rights.

I am suggesting expanding their water right- instead of only the right to do X, Y, Z with the water, take whatever right to the water they do have, in terms of amount of water, and say "you can do whatever you want with this much water". How to allocate resource rents doesn't have much effect on the market structure itself.

A lot of vitriol against supply and demand without any evidence.

Food is life. Food is culture. Just as much as water. Which countries have had famine, those that allocate via some system of food rights, or those that had a free market in food? The largest examples of famine I am aware of, in the USSR and Maoist China, were driven by some central allocation of food rather than a market. Not a good record.

One of the great features of markets is that things don't need to be decided collectively. Perhaps 90% of people want to wear blue T shirts, but I want a red one. If we collectively decide, I get a blue T shirt. In the market, I buy a red T shirt- perhaps at a very slightly higher price due to less economy of scale.

We certainly know of areas where vanilla markets can fail- externalities etc, but these do not apply to the situation here. The existing system of water rights doesn't feel like a collective decision, but rather entrenched special interests and lobbyists.