The two-year study of water efficiency in multifamily buildings found that, on average, California apartment buildings used 6 percent less water in the first half of 2015 compared to the first half of 2013. A very dry May and June saw upwards of 10 percent savings.
These savings are substantially less than the 27 percent reduction reported for California as a whole in May, and also fall short of Gov. Jerry Brown’s required 25 percent reduction.
Savings levels varied across the population of buildings in the study. Apartment buildings that implemented retrofits achieved markedly higher savings than other buildings in the study, reducing water use by 25 percent in the first half of 2015 relative to 2013. Retrofits ranged from comprehensive water fixture overhauls (sinks, showers, toilets) to landscaping upgrades, like drip irrigation replacements.
“Typically, multifamily building owners pay for their buildings’ water bills rather than passing on costs to tenants. Without that financial incentive, residents often do not conserve water through behavioral changes,” said Barun Singh, founder and CTO of WegoWise.
The study also shows California apartment buildings “are brimming with untapped efficiency potential,” according to Singh. “Apartment building owners that do implement targeted upgrades can meet statewide goals while lowering utility expenses and boosting cash flow: a pretty compelling incentive.”
Dramatic savings were often the result of simple measures, such as toilet upgrades, WegoWise says. One hotel in East L.A. saved more than 30 percent annually after a toilet retrofit. Community Corporation of Santa Monica, an affordable housing developer, decreased water usage by over 12 gallons/bedroom/day—a 24 percent drop.
The WegoWise study drew upon a database of over 700 multifamily buildings across the state from January 2013 through June 2015. Data includes 21,000 units, almost 32,000 bedrooms and 2.4 billion gallons of water usage over the two-year period.