The thing is, there’s more than one dam. Keeping Lake Powell ‘full’ means Lake Mead gets less water for their electric generation. And the upstream lakes have to release more water than they want to.

They’ve been haggling over that water forever and no one is going back to their constituents admitting defeat so Phoenix can have more golf courses per capita than any other place on earth. Maybe making that up but I’ve lived in the Phoenix valley for almost 25 years and there’s a lot of golf courses.