A pilot project in California is using captured rainwater to supply wash water for winemaking, saving thousands of gallons of freshwater per day.

The project uses a GE reverse osmosis system and total organic carbon analyzer at the University of California Davis winery. Rainwater is captured via downspouts in a 1,200 gallon tank, then feeds through a 50-micron filter before being pumped into two 45,000 gallon storage tanks that supply the treatment system. Rainwater contains fewer contaminants than groundwater sources, meaning it requires less filtration to be purified to a usable level for washing.

The university is treating about 7,000 gallons per day, replacing water that would otherwise have to be drawn from a freshwater aquifer. In addition to that, the winery has a secure supply of water that it can use during drought conditions without having to negotiate water rights agreements.

Wine industry solutions provider Winesecrets is also collaborating on the program.