California faces an environmental challenge that many places face: demand for water is rising while supply is falling. Water managers across the country are looking for ways to help their customers cut back on water use. In Sacramento County, the water management agency offers two free water conservation programs to any of its customers who request them.
In the Water Wise House Call (WWHC), a trained water efficiency professional visits a customer's home, checking appliances, plumbing, irrigation systems, and other areas to look for leaks and optimize for conservation. The technician explains his or her findings, and provides recommendations and any necessary training. The technician also leaves the customer with informational brochures, toilet leak detection tablets, and a watering schedule, and provides the customer with a written report of the findings and recommendations within 10 days of the house call.
The agency's other program, the Data Logger service, offers customers detailed information about their water usage. The agency installs a water meter on the customer's home for one week. The meter reports the water usage at each fixture in the home, including irrigation, appliances, faucets, tubs and showers, and can even detect leaks. The customer receives a detailed report that reveals their patterns of water use, and can show whether high water use is caused by personal habits or leaks. As in the WWHC program, the customer also receives written recommendations, but in neither program do the reports suggest a target amount of water use the customers should aim for as they go forward.
The Sacramento County Water Agency has offered these programs since 2000. The authors of this paper took the opportunity to investigate the impact of the programs, as the agency had data about customer's water use before and after participating in the behavior-modification programs (in the form of the customers' water bills, which indicate their water usage). The agency also had data from all customers who didn't participate, creating a control group.
The researchers randomly selected 50 households that participated in the WWHC program and 50 that participated in the Data Logger program. Each group was matched with a control group of 50 households of similar lot size. The researchers compared the water usage of all the groups for 5 to 6 months before and after participating in the program (the control groups were compared during the same time period). The researcher believed that this longer duration would help control for unusual spikes or dips in water usage that might occur during shorter periods of time, and also would allow for plenty of time for customers to adjust their habits based on the interventions.
What they found was interesting. Both groups who participated in the water conservation programs did, in fact, significantly reduce their water use, and the control groups didn't. The WWHC program was effective for 62% of people participating (the remaining 38% did not decrease their water use), while the Data Logger was effective for 84% of participants. The authors speculate that the Data Logger program may have been successful for more people because it provided more detailed feedback: “This greater level of detail likely leads to more meaningful, actionable, and effective behavior changes.”
But, it's important to note that the people who participated in the two programs had much higher levels of water use than the people in the control group. These programs are voluntary, and appear to attract people who have above-average water use and want to reduce it. After participating in the programs, these customers' water use fell to the average water use of the control groups. The authors suspect that this level of water use represents “a status quo, a water consumption level that is comfortable.” Also notably, the customers for whom the programs were not particularly effective had a lower average water use than those who benefited from the program. The authors explain that “these results suggest that water conservation programs may be most effective in reducing water usage for households that use substantially more water than the comfortable status quo.” The authors suspect that getting people to move from their comfortable water use level to something lower would probably require “greater motivating forces” than this approach employed.
The Bottom Line
The approach investigated here--giving people who were motivated to change their behavior specific information about the desired new behavior and feedback to help them gauge their success--did achieve water conservation results. However, it's important to note that reductions were only achieved by people who had abnormally high levels of water use at the outset, and they reduced their use to average levels. The program was not successful at moving people from average water use to greater water conservation. Getting those results would likely require more intensive behavioral interventions, such as creating specific targets, using normative influences, offering incentives, or other techniques that were not part of this study.