Once thought to be the wave of the future, turning seawater into drinking water is proving to be a tough sell in California. Desalination of ocean water has long held promise, but the dream of sticking a straw in the ocean and getting unlimited clean water by simply opening the spigot of technology — that’s looking less and less likely here.

Scarcely a decade ago, when “desal” was relatively new to the state and optimism was high, there were 22 different proposals for plants up and down the California coast.