In California, even before a droplet of treated water reaches a consumer’s faucet, approximately 8% of it has already been lost because of leakages in the delivery system. Countrywide, the waste is much higher at 17%. This signifies an unexploited opportunity for water savings, as per a study from the University of California, Davis.
Amanda Rupiper of the UC Davis Center for Water-Energy Efficiency conducts a water quality analysis. Image Credit: Paul Fortunato/UC Davis.
Published in the journal Environmental Research Letters, the research is the first extensive evaluation of utility-level water loss in the United States. It found that reduction of leakage by utilities can be the most economical tool in an urban water manager’s toolkit, provided utility-specific methods are employed.
When I first heard about ‘leaks’ I thought it sounded boring, but leaks are a huge component of our water systems and have a larger opportunity than many other water-saving methods to make an impact. As the first state to regulate its water losses, a lot of eyes are watching California, and this is an opportunity to impact policy here and elsewhere.
Amanda Rupiper, Study Lead Author and Postdoctoral Scholar, Center for Water-Energy Efficiency, UC Davis
During a multi-year drought, the passage of Senate Bill 555 in 2015 made California the first state and among the first countries in the world to mandate water utilities to control their water losses.
Be Specific
Utilizing data from over 800 utilities across California, Tennessee, Georgia and Texas, the researchers defined water losses throughout the country. They created a model to measure the economically efficient level of losses and used that model to compare numerous water loss regulations and modeling methods.
The study discovered that one-size-fits-all methods to leak management are not operative, cost-effective or equitable for utilities, which differ in resources and size. Uniform methods could result in the mismanagement of urban water losses. However, applying utility-specific performance regulations can offer a similar quantity of water savings at a profit for both utilities and society.
“Regulations that impose a uniform standard across all utilities will result in water reductions that are too stringent in some cases, too relaxed in others, and too costly overall,” the article concludes.
Saving Drips Without Draining Utilities
Preferably, no leaks should happen in a system. However, while some leaks are noticeable and accessible, others can be harder and more expensive for some utilities to locate and repair. The study model measured when utilities could save the most water for their dollar to detect and repair leaks in the system.
They learned that for the median utility, it is cost-effective to reduce water losses by 34.7%, or 100 acre-feet annually. The median cost of water savings from managing leakages is $277 per acre-foot — cheaper than most conventional water management tools, including rebate programs and conservation campaigns.
It’s cost-competitive to do this and should be part of the profile of how we manage our water. We tend to think of leaks as being a little drip, but leaks are not inconsequential. Drips add up to big flows, and we can’t ignore them anymore.
Amanda Rupiper, Study Lead Author and Postdoctoral Scholar, Center for Water-Energy Efficiency, UC Davis
The co-authors of the study include Frank Loge, Joakim Weill and Katrina Jessoe of UC Davis, and Ellen Bruno of UC Berkeley.
Journal Reference:
Rupiper, A., et al. (2022) Untapped potential: leak reduction is the most cost-effective urban water management tool. Environmental Research Letters. doi.org/10.1088/1748-9326/ac54cb.