It looks to me like the San Diego transfer is headed down a dead-end road. I think that the potential environmental costs and liabilities will be more than the farmers want to risk.
The Salton Sea is a huge environmental resource. It has become a part of the western migratory bird flyway. Congress is spending millions on finding a way to save it. The good news is that a way has been found to do that. The bad news is that the San Diego water transfer will affect the solution.
If the transfer shrinks the sea, the costs will increase dramatically. The cost for saving the sea is estimated to be $10 to $20 million a year if the water going into the sea stays the same. If on-farm conservation reduces the flow to the sea substantially, the costs could climb to $50 million or more a year. This would be much more than the farmers could handle.