Water leaks are going undetected on residential properties across West Marin, and water district authorities are working to find new ways to fix the problem as they contend with a drought emergency. 

Technologies like flow meters are making it easier for utilities to more closely monitor usage while avoiding the high cost of updating meters. They also shift the onus onto customers. 

“It’s a cultural shift,” said Tony Williams, chief engineer at North Marin Water District. “As a consumer, you become smart about your water.”

A staff report by the Inverness Public Utility District found that over the past year and a half, its customers experienced 17 large leaks, wasting over a million gallons, enough to supply the entire system for half a month. Fourteen of the leaks occurred at second homes or vacation rentals, where customers were away and not able to detect them as quickly, and most were failures of buried lines or irrigation systems rather than above-ground pipes. 

“In times like this, where we’re tight on water, we need to have better tools to find leaks quickly, and to shift responsibility onto the customer,” said Wade Holland, the district’s customer services manager.

Last month, the IPUD board gave the go-ahead to buy at least 150 flow meters and sell them to customers at half price. The battery-powered devices, made by a San Luis Obispo-based company called Flume, strap onto the riser of a water meter and transmit usage data via WiFi to both customers’ smartphones and a centralized dashboard monitored by IPUD. The sensors will alert customers, and water operators, to leaks that might otherwise go undetected for some time. 

Mr. Holland said once customers install their own Flume devices, many find right away that they had a leak. IPUD forgives the cost of leaks on the customer end, but with the drought, the district is reconsidering this policy for short-term rentals and second homes. The board may require that these customers install a Flume if they want to avoid paying the full price for leaks. 

Inverness resident Kathy Hartzell told the IPUD board she had already bought a Flume for her meter. She said it took her 15 minutes to install, and she immediately identified an issue. “I bought a new washing machine,” she said, “so I’m no longer hogging 40 gallons to wash my clothes.”

IPUD serves roughly a dozen older meters that aren’t compatible with Flume, but the district already had plans to replace those meters, since they tend to underestimate water usage. Jim Fox, the district’s chief of operations, estimated that each outdated meter would cost just a few hundred dollars to upgrade. 

The Flumes will also help ease the transition into a water rationing program that IPUD may enact later this summer. Last month, the board tentatively decided on a method of rationing that would allow a set number of gallons per day on each meter, with additional gallons allotted per resident. Mr. Holland’s staff report suggested that Flumes could eliminate the need to send out meter readers any more often during rationing, since customers could check their own compliance. But for now, the Flume system wouldn’t be enough to replace traditional meter readers altogether.

“We would not use the Flume data to confirm compliance with rationing,” Mr. Holland said. “The dashboard isn’t going to help us, except in the leak area, until we have more customers participating.” 

IPUD isn’t the only district in Marin to consider Flumes: the Muir Beach Community Services District is considering buying some of the devices, and Marin Water has already distributed more than 1,100 of them to its customers at a 75 percent discount.

Bolinas Community Public Utility District general manager Jennifer Blackman said her district deals with some sort of leak on the customer side about once a month, often at houses where no one is home. “In the normal course of things, the leaks are often not caught until the meter is read for the next billing cycle,” she said. At that point, customers have to consult with a plumber to find the source of the leak. 

BCPUD advises customers to go out and check their own meters regularly, and to turn the water off at their house valve if they plan to leave town. “It is possible to [alleviate the leak problem] in a very low-tech way,” Ms. Blackman said. A number of BCPUD customers have purchased their own Flumes to make the process easier. Like IPUD, the district forgives the cost of customer leaks, but only if the customer provides a written request showing the leak was beyond their control or the result of excusable neglect. 

Ms. Blackman is talking with Flume about a potential discount program, but she acknowledged that internet connectivity might be an obstacle for some customers in Bolinas. Mr. Holland said IPUD knows of about 15 Inverness customers who likely don’t have internet service and would not immediately be able to install a Flume.

In 2019, North Marin Water District spent $6 million to replace more than 20,000 meters, nearly all of its Novato service area, with Neptune smart meters that transmit data via radio signal. Unlike Flume devices, which strap onto pre-existing infrastructure, this upgrade required the costly replacement of every water meter. 

Last summer, N.M.W.D. looked to Flume instead of smart meters for a West Marin pilot project that could become permanent. Not only would installing smart meters around Point Reyes Station have been expensive, but it also would have required installing radio repeater antennas. Instead, the utility charged 32 West Marin customers $50 each for Flumes. 

Mr. Williams called the Flume program a “stopgap,” but suggested the district could provide Flumes to its remaining customers rather than replacing more meters. He said customers are the “first responders” to leaks, since N.M.W.D. does not track them. The district does adjust customers’ bills if they are unusually high and the circumstances suggest a leak.