The rain-watered lawn: Informing effective lawn watering behavior.

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 results show that 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.

Evaluating the effectiveness of water restrictions: a case study from Southeast Florida.

One of the most commonly employed water conservation strategies is to restrict lawn watering to limited times on specified days. Water managers typically assume that limiting the frequency and duration of lawn watering will reduce water use. Consequently, the effectiveness of water restrictions is often evaluated based on observed compliance to the specified schedule, whether or not actual reductions in water use are achieved. This assessment approach is more practical than quantifying the reduction in water use brought about by restrictions because quantification of lawn water use is hampered by difficulties in disaggregating the various components of residential water use. Dual meters to separately meter the portion of public supply devoted to lawn water use are rare, and for households that withdraw water from private wells, canals, or ponds for lawn watering, there is no record of such water use at all. As a consequence of this gap in water use data, compliance to a prescribed frequency of watering is often equated with effectiveness. In this paper we develop an alternative metric for evaluating the effectiveness of water restrictions and present a case study in a suburban area in Southeast Florida that illustrates some of the challenges of quantifying lawn water use and explores some of the limitations of day of the week water restrictions as a conservation strategy.