Pool covers could cut evaporation by 95 percent, Cal Poly study shows

A study conducted at the Cal Poly National Pool Industry Research Center has determined that using pool covers could reduce 95 percent of evaporation from California pools, enough to supply a city of about 500,000 for a year.

Study investigators took daily water-level measurements and weekly water-chemistry readings at eight university pools over 90 days, starting in July. Climate data included air temperature, wind speed and rainfall collected at a Cal Poly weather station.

The study was sponsored by the National Plasterers Council, California Pool and Spa Association, Association of Pool and Spa Professionals, and the Independent Pool and Spa Service Association.

Principal investigator Misgana Muleta, an associate professor in the Civil & Environmental Engineering Department, said use of pool covers could save more than 55,000 acre-feet of water per year statewide. The study, which estimates 1.18 million residential pools statewide, doesn’t take into account how many pool owners already use covers. The full report will be released on the National Plasterers Council website in coming days.

This story was originally published January 19, 2016 at 3:16 PM with the headline "Pool covers could cut evaporation by 95 percent, Cal Poly study shows."