Reducing Evaporation To Save Water

The latest water scarcity solution that sounds like science fiction: Don't let it evaporate.

Government researchers in the U.S. and abroad had already studied how coating water molecules in coconut or palm oil could slow evaporation. The technique had been used on small water bodies, including swimming pools, Nature reported, citing Moshe Alamaro, an engineer at the Massachusetts Institute of Technology in Cambridge.

Now evaporation suppressants are being applied to larger bodies of water. A field test in Texas attempted to make it work last year.

"The $325,000 test ran from July to October on Lake Arrowhead, a 21-square-kilometer reservoir that serves the city of Wichita Falls. Flexible Solutions International, a company in Victoria, Canada, that makes evaporation-reducing coatings for small water bodies, programmed a boat to run on autopilot and make a grid pattern across Lake Arrowhead spreading the coating behind it," the report said.

The results, published by the Texas Water Development Board, found that the suppressant was promising, but the results were not conclusive.

"Our analysis suggests that, with an 87 percent statistical level of confidence, the suppressant reduced evaporation. Our analysis also suggests that the suppressant was effective in reducing evaporation by about 15 percent, although statistically there is about a 74 percent probability that the reduction lies between 0 percent and 26 percent," the analysis said.

Mark Wentzel, a hydrologist for the Texas Water Development Board and co-author of the report, said the coating likely helped. But he added, "I wouldn’t stake my life on it,' Nature reported.

More data is needed before this method could be viewed as a viable option.

"This study did not consider the influence of evaporation suppression on water supply nor the economic costs and benefits of evaporation suppression. These analyses are needed prior to fully considering evaporation suppression as a water supply strategy," the analysis said.

Other solutions to water scarcity that sound a little wacky: weather modification, which could include flooding Death Valley with seawater, cloud-seeding with drones, collecting water out of thin air, and waterless toilets.