Investigating the Effectiveness of Irrigation Restriction Length on Water Use Behavior

As global drought and urbanization raise severe concerns about outdoor water use, restrictions on lawn watering on specific days and/or times have been widely adopted worldwide. However, the literature rarely investigates the impacts of watering restriction lengths on water use behavior. This study investigates the motivation for water conservation by accounting for individuals’ intertemporal time preferences and precipitation probability distortion, which captures bounded rationality. Our findings suggest that a longer restriction length (i.e., allowing a less frequent watering time) may increase the likelihood of immediate irrigation, but this may not be the case for homeowners who prefer immediate rewards and delayed costs; we have labeled these as impatient homeowners. Impatient homeowners are more likely to postpone irrigation if the delayed costs of underwatering (e.g., discolored grass blades, insufficient nutrients to the grassroots, etc.) are more discounted than the costs of overwatering (e.g., a loss of lawn quality, more diseases, excessive thatch, etc.) Additionally, we empirically evaluate homeowners’ time perception and the impacts of the watering restriction on water use. The results show that lengthening restriction intervals (i.e. the time between allowed watering) increases irrigation frequency and water consumption. Based on our results, shortening the watering interval to a prohibited-hours restriction may be more effective in reducing water use by impatient homeowners.