The Colorado is the great example of a river that would benefit if water users had to pay the actual value of the water they use. If people in Vegas want to have a pool, let them do it as long as they buy water on the market at a price that reflects the actual costs, including environmental. A lot less people would want pools and use would go down. Let farmers up river who are growing crops at a loss, but have long standing water rights, sell their water to users below and stop growing some crops that they lose money on anyway. If these transactions were taxed, the money collected could go to restoring the environment, fish etc. I know it will likely never happen. Just wishful thinking.