The Carlsbad desalination plant – from http://carlsbaddesal.sdcwa.org/overview/

I haven’t made any secret of the fact that I live in California, so it shouldn’t be surprising that drought is on my mind a lot lately.

California is very, very dry.

This is normal-ish: the parts of California that don’t get snow tend towards wet, green winters and dry, brown summers.

This becomes a problem, though, when you add two human factors: we have more humans (and especially the associated agriculture) than we have renewable fresh water resources to support and human emissions are changing the climate in a way that really looks like we’ll be getting even less water coming in the future.

It’s already quite bad.

There are parts of the state where there’s not enough fresh water already, and so those parts depend on wells that were already starting to fail a decade ago and have now reached the point that aquifers collapsing (due to the water having been drawn down too far) is becoming a threat to surface infrastructure.

Really; some parts of the Central Valley have subsided far enough that roads and bridges are being damaged.

This is pretty much unstoppable.

The Central Valley will continue to sink for a while, even if we stopped drawing any more water from those aquifers today. It will take decades for the aquifers to settle into a new stable state, during which time the surface will continue to subside.

There is quite literally nothing we can do to stop it, but we can still keep it from getting worse.

The first step is always acceptance.

This may be the only point where I agree with 12-step programs, but accepting that the problem exists and has to be dealt with really is step one: we are using far more water than the systems around us can provide, and we will not be able to continue much longer.

Something will stop it; the only choice we have is to stop it ourselves or to to let disaster stop it for us.

Fortunately, we do have alternatives.

We don’t actually have to use groundwater in places where there’s no surface fresh water.

We are very fortunate to be on the coast of an ocean; California has 840 miles of coast, all of which is right there next to a vast source of water; we just have to … freshen it up a bit.

And we actually know how to do that.

The pic at the top of this page is of the Carlsbad desalination plant built by the San Diego County Water Authority and opened in 2015.

It is currently producing around 50 million gallons per day of fresh water, which supplies 125 gallons per day to 400 thousand people.

That serves around 1% of our population.

The plant cost around $750 million to build; 100 of them would serve our entire 40 million population and cost around $75 billion.

So, not cheap but not breaking the bank in the context of a state with a $222 billion annual budget.

True, that’d be 1 treatment plant for every 8.4 miles of coastline but we could probably afford to make them prettier if we were building that many of them.

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