Or you know, you could protect the water you do have evaporation and make farmers better utilize the water they have. But instead we get open air canal, field flooding, etc.
You also still need rain/snow to fall in order to fill the reservoirs.
I don't think any one is going to die from lack of water in California, so I don't see how we are putting the welfare of the environment ahead of the welfare of people. Furthermore, protecting the environment protects the welfare of future people. If people had to pay the real cost of water in California, no body would want a green lawn and there would be no field flooding.