Federal lawmakers need to get over the history of water rights here. The system was built on assumptions that just don't hold (more water was apportioned than ever flows). You can give each state an amount and let them figure it out, or take all existing rights and re allocate them federally. But it needs to happen, and urgently. "But people will lose their income!" - Thats a symptom of requiring these people to work…
You may need to read up the definition of that word