AMERICA - South West Looks at New Water Source

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"Why Californians Will Soon Be Drinking Water from Mexico's Ocean" by Ben Jervey, Good 4/26/2011

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Yesterday, the Department of the Interior released a pretty scary report about the impacts of climate change on water in the Southwest. The report (PDF) ("Reclamation, Managing Water in the West"), which "represents the first consistent and coordinated assessment of risks to future water supplies across eight major Reclamation river basins," paints a frightening picture of an already arid region that undergoing a long, painful desertification.

In the past, we've looked at the desalination of seawater as an option for providing drinking water in regions that lack freshwater, like Australia and the American Southwest. While I wish there were ways to keep demand for freshwater within the means supplied by natural systems, I'm of the opinion that desal isn't just going to be an option, but a necessity for some areas by mid-century.

So it was fascinating to read Rob Davis's voiceofsandiego.org feature on how lax regulation in Mexico could make it easier and cheaper to build desalination plants off the Baja coast, and how those could soon be supplying water to Southern Californians.

Desalination offers the promise of being a drought-proof local supply in an arid region that imports most of its water from hundreds of miles away. But it is highly regulated in California because of its environmental impacts, such as massive pumps that suck in and kill fish larvae and other marine life...

"They don't ask as many questions" in Mexico, said Peter Douglas, executive director of the California Coastal Commission, the state agency that regulates coastal development. "They don't protect the environment like we do in California."

Right now, authorities are talking about building one desal plant in Mexico. There's another planned in the San Diego area, that's a similar size. But those aren't going to get us very far. On his blog, John Fleck digs into these numbers a bit:

But what struck me about this project, as Rob describes it, is how small it really is. 50 million gallons per day is about 56,000 acre feet per year. The average Lake Mead shortfall during the ’00s was 1.2 million acre feet per year. That’s the supply-demand imbalance we’re talking about. That would mean 20-plus desal plants just to close the current gap.

Conservation measures are, of course, essential, but I simply don't see any way that Southern California will be able to sate its thirst for drinking water without these massive, energy-sucking plants. We'd better figure out how to build and operate them without totally ruining the coastal ecosystems, and without using so much carbon-spewing energy that will just worsen the freshwater shortages in region.

"Mexico's Ocean Could Become U.S.'s Drinking Water" by Rob Davis, Voice of San Diego 4/24/2011

Excerpt

Just before the toll road stretching south from Tijuana enters Rosarito Beach, it veers inland, away from beautiful blue-water views, swinging wide around an industrial power plant complex, all filled with metal smokestacks and white fuel tanks, a major source of Baja California's electricity.

There, water suppliers from across the Southwest are studying what would be the first project of its kind: tapping Mexico's ocean as a source of the United States' drinking water.

This idea has been a long time coming. I can see that Environmentalist will have concerns, like what effect the "debrine" being returned to the ocean will have, but that does NOT mean this is not a good idea. It just needs to be well designed.