As 20 million gallons of drinking water rushed down Sunset Boulevard and flooded the UCLA campus this summer, drought-conscious residents threw up their hands.
How are three-minute showers going to make a difference, they asked, when the city’s pipes are bursting?
Turns out the UCLA flood was just a drop in the sea of potable water that leaks or blows out of underground pipes. California’s water distribution systems lose up to 228 billion gallons annually, the state estimates — more than enough to supply the entire city of Los Angeles for a year.
The drought and massive pipe breaks this summer have focused attention on leaking water infrastructure (“This will not be the last one,” Los Angeles Mayor Eric Garcetti warned after the UCLA break.) and raised questions about funding pipe replacements. As officials grapple with the answers, they have to measure leaks and decide if replacing pipes is cost-effective, experts say.
“There will always be a minimum amount of leakage,” said Reinhard Sturm, a member of the American Water Works Association Water Loss Control Committee. “You can try to get to the technical minimum, but the money has to be available to do that, and it has to come from somewhere.”
To gauge leakage, cities and utilities tally how much they sell, plus an estimate of what is stolen or inaccurately metered (some customers steal water by installing pipes that route water around meters). Then they subtract the sum from the total amount of water supplied to get a loss estimate.
Some utilities in Northern California had the worst leakage in recent years. The city of Sacramento lost 135 gallons per service connection per day — more than enough daily water for the average Angeleno — according to the California Urban Water Conservation Council’s 2012 data, the latest available. The statewide average loss per service connection — the hookups to homes or commercial buildings — in recent years was 49 gallons.
Water seeping from joints and fittings takes the path of least resistance, said Sturm, who is also a consultant to the Los Angeles Department of Water and Power. Much of it just stays in […]