A seawater desalinization plant is currently being built in Carlsbad, to provide an additional source of potable (drinkable) water for the county. Is this a good idea, or a bad idea?

Those who support it stress the importance of securing additional water supplies for the county that are locally available, not threatened by major fault lines, and constitute a reliable and renewable resource. The Carlsbad desalinized water plant meets these tests.

But those who are skeptical about this potential new source point out the possibility of damage to marine ecosystems near the intake and outfalls, the high cost of the process, and the fact that high-volume desalinization plants require a lot of electricity.

So, who has the better argument?

At this point in time, I have to give a nod to the proponents. Yes, it is a rather expensive water supply, but there are no more cheap sources. Any other possible new source will be equally expensive. And while certain potentially adverse effects to the ocean can be identified, the majority opinion seems to be that these are not likely to be unacceptably significant.

And there is no question that we will most likely need this water in the future. Our current northern California imported supplies (from the Feather River via the California Aqueduct) clearly can’t be considered sufficiently reliable under extended drought conditions, such as at present.

The Carlsbad plant has been approved and is under construction. Let’s monitor its operation carefully, and after a few years we should have the data we need to evaluate the plant, and a much better idea of its positive and negative attributes.

That will inform us as to whether we should consider building more such plants, or not.