Opponents of desalination in California most often cite the cost of desalination, and the environmental toll of the energy required to run desalination plants.

Opponents of desalination in California most often cite the cost of desalination, and the environmental toll of the energy required to run desalination plants. They also don't like the idea of putting salt back into the ocean. Generally speaking, California is full of NIMBYs who will reflexively oppose virtually anything new, then work backwards to then find disingenuous justifications for their opposition.