When Rigo Cosio steps on to a property, he goes looking for water waste. Cosio works as an inspector for the city of San Diego, California, and he visits homes in the city every day, helping property owners find what’s making their water bills so high. “Ninety percent of the time, outdoor irrigation systems are the culprit,” he said.

At the home of one customer, Cosio found that irrigation was the cause of her water bill doubling to more than $800. The outdoor water pressure was set to 120 psi, well above the recommended pressure, and the distribution uniformity of her system was poor. Some parts were set to be watered multiple times per day by more than one head. “There’s your ‘ah-ha!’ moment,” he said.

There are only a handful of city inspectors, but they’re out there every day, responding to calls. Cosio’s very existence suggests that there’s room for savvy San Diego contractors to improve irrigation systems around the city. He certainly feels that where you find one problem, more are hiding nearby. “You just put in the work,” he said. You find one thing, then another thing, and another and another.”