Road Signs Plus Mailings Reduce Lawn Watering

This pilot with control group found that households watered more conservatively than with water restrictions alone if they were also informed of recent rainfall totals.

Highlights:

Water restrictions are a common municipal water conservation strategy to manage outdoor water demand, which generally represents more than 50% of total urban-suburban water use. Although water restrictions are designed to limit the frequency of lawn watering, they do not always result in actual water savings. The project described here tested a weather-based add-on water conservation strategy in a South Florida suburban community to determine if it promoted more effective lawn watering behavior than mandatory water restrictions alone. The ?rain-watered lawn? pilot program was designed to inform people of recent rainfall and how that contributed to naturally watering their lawns and offset the need to irrigate as often, or in some cases, at all. The goal of the study was to determine if homeowners would water more conservatively than with water restrictions alone if they were also informed of recent rainfall totals.

The study involved 627 households - 321 in the treatment group and 306 in the control group. The researchers created a highly visible road sign that matched existing road signs, and placed them close to the entrances of the experimental neighborhoods. The signs indicated rainfall levels over the last seven days and reminded residents that one inch of water per week was adequate for most homes in the area. The bottom text asked: "Is rainfall alone meeting the water needs of your lawn?" Those in the experimental group also received a postcard and leaflet about the signs.

Households in neighborhoods where the add-on rain watered lawn strategy was implemented watered up to 61% less frequently than the control neighborhoods with water restrictions alone. This study demonstrates that weather-based information strategies can be effective for conservation and suggests that a program that focuses on coupling lawn watering behavior with actual climate variables such as rainfall can yield significant water savings. This study holds significance for municipal areas with water restrictions and provides a model to help improve outdoor water conservation.