Evaluating the Impact of Residential Landscape Audits Using 5-Second Water Use Data

We used 5-s water use data to evaluate the effectiveness of residential landscape water audits in summer 2022. Fifty-nine households in two northern Utah cities were monitored for 2–5 weeks before and 3–10 weeks after an audit. We found that the distribution of weekly irrigation volumes postaudit was statistically less than the distribution preaudit (significant at the 1.9E10-5 level). Collectively, the participants reduced their landscape irrigation water use by approximately 379,000 L per week (100,300 gal per week; 0.3 acre-feet per week). We also analyzed changes in irrigation event volume, duration, frequency, and the number of days between events at three scales: full sample, user group, and individual household. We found that households reduced their use by reducing the duration of irrigation events. We also found that large users achieved the largest savings by reducing their use toward their landscape water budget. Follow-up interviews confirmed that adjusting sprinkler watering times was the most commonly implemented audit recommendation due to its simplicity. Some households also followed recommendations such as altering nozzle distribution and replacing broken nozzles. Household feedback identified eight improvements, notably the addition of a postaudit follow-up and referrals to vetted contractors. Our analysis shows that landscape water audits reduce use and are a vital conservation tool.