Opinion: Water desalination is here. But is it sustainable?

In a very dry state, turning to the sea as a source of water for drinking, bathing and irrigation has its attractions. Desalination is drought-proof — the ocean is one pond we can’t empty so quickly. It’s more expensive, but the cost is relatively stable, and as technology makes the process more efficient, those costs have been trending downward.

But Californians should be leery about desalination as anything more than a backup plan that might be appropriate for a few spots up and down the coast. And that’s not just because the process involves sucking up some fish larvae, and spitting out brine (which is quickly diluted) or even because it’s an electricity hog. (The California State Water Project is the single biggest user of electricity in the state because of the energy needed to move water from one place to another — especially over the Tehachapi Mountains to Southern California, but desalination, gallon for gallon, uses far more power.)

Other improvements to desal are expected to bury pipes so they don’t affect sea life, reduce electrical use and use solar and wind energy to power what’s needed. Poseidon Water already plans to place solar panels at its Huntington Beach facility, if it gets the OK to build it, but that covers only a fraction of the plant’s electrical needs. It also is looking for ways to purchase solar power directly — perhaps by buying its own solar array in the desert.

That’s good for a little water lift when we’re really dragging, when the ground is so parched that 500-year-old trees are dying off because they’re too stressed to fight off pests. What really has to improve, though, is Californians’ historically profligate use of water.

We have several ways of tackling what will surely be more common and more difficult droughts. Desal is just one small part of a much bigger picture that has to include reclaiming “used” water, capturing more of it before it runs out to sea and, yes, acting as if arid conditions aren’t just something afflicting us for a temporary spell.

As a whole, Southern Californians have been model drought citizens. We’ve taken it seriously. We’ve torn up lawns, rerouted gray water, mellowed the yellow.

The challenge now is not to get drought fatigue. We can’t afford it.

Desalination can provide some insurance when times get very bad. What it can’t do is start the lawn sprinklers again. It also can’t be used as an excuse for rampant development, heedless of whether there will be enough water in droughty times to serve everyone. Saving and reusing water are still our best bets. As a policy matter, it’s worth worrying that people will see the depths of the oceans as a great reason not to conserve and reclaim.

If Poseidon builds the Huntington Beach plant, it will produce 15% of the total water historically used in the Orange County Water District — which by the way, has been the model of progressive thinking, developing a full-bore water reclamation project back before most people had even heard of such a thing. Fifteen percent equals not a lot. But that’s also a third of the district’s imported water — so if there ever are Metropolitan Water District cutbacks, the desal plant would become a far more important source.

Or look at it this way: If the 2.4 million customers cut their water use in half for good, the Huntington Beach plant could contribute 30% of the water people need.

Desalination works as a major water source in Israel, not because it can provide enough water for 40-minute showers, but because Israelis already are very careful with their water consumption, which is about one-fifth that of the United States’ per capita. Unless we want to foul the coastline with plant after plant, desalination works here as an insurance plan for the worst of times. When people question whether desalination is a sustainable way to get our water, the answer has less to do with the technology than with how we use it.

The El Niño rains are coming, they say, and the drenching will be much appreciated. But state officials should be using the drought as a reset button: Now that we’ve shown how good we are at saving water, this should be the new norm.

No more major construction proposals that don’t come with a plan for how they will obtain — and conserve — water, or mitigate their water use by helping to install technology elsewhere for capturing stormwater runoff. Landscapes must become a part of land-planning as much as the buildings they surround, and should reflect the fact that we live in a low-rain Mediterranean climate. No more pretending that this is just a warmer, sunnier version of the Northeast.

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