Ocean desalination could help expand water supplies for Western communities and industry, but the high cost makes it an unlikely solution for large-scale agricultural irrigation.
California estimates put the cost of new seawater desalination at 3,400 to 3,700 dollars per acre-foot.
That’s more than twice the roughly 1,444 dollars in average gross farm revenue generated per acre-foot of irrigation water applied.
Even at 3,000 dollars per acre-foot, desalinated water could add thousands of dollars per acre in costs for crops such as lettuce, strawberries, and almonds.
Desalination uses reverse osmosis to remove salt from seawater.
While the technology is established, it requires significant energy and infrastructure investment.
Lower costs have been achieved in countries such as Israel and the United Arab Emirates, but differences in energy prices, project scale, and regulations make those figures difficult to replicate in the American West.
Desalination may supplement municipal and industrial water supplies, but its economics remain a major obstacle for farmers.
