Maybe they could have subsidies for desalination or something…Major downsides I see are lots of save the oceans/whales/dolphins/sea lions/environmentalists blocking any major expansion. I’d assume energy use is also high for desalination plants and those 2 reasons are probably why we don’t do it already.
http://en.wikipedia.org/wiki/Desalination
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Due to relatively high energy consumption, the costs of desalinating sea water are generally higher than the alternatives (fresh water from rivers or groundwater, water recycling and water conservation), but alternatives are not always available.
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