Water Audit Encourages Residents to Reduce Consumption

Abstract

The North Marin (Calif.) Water District (NMWD) conducted a free home water audit for randomly selected customers from single‐family detached homes. All were in the upper quartile of water use; i.e., residents used about 41 percent more water than was used in the average single‐family home in the service area. At the time of the study, because of publicity about drought in the region, most households had reduced water consumption. For this reason, NMWD used a control group so it could isolate water saved by the audit program. The audit included an interview about patterns of water use, leak identification and repair, installation of low‐flow shower heads and toilet tank displacement devices, evaluation of lawn irrigation practices and recommendation of an irrigation schedule, and distribution of free publications and promotional items. Average annual use declined significantly after the audit, about 16 percent for the sample group and 11 percent for the control group. The difference, or 4.6 percent (9,188 gal), could be attributed to the audit project. Of this amount, 7,270 gal were estimated as being saved inside the home. Only 1,918 gal (less than 21 percent) were calculated as being saved outside the home, far less than NMWD had expected.