Large Landscape Urban Irrigation: A Data-Driven Approach to Evaluate Conservation Behavior

Abstract

Nonresidential irrigation is a unique and important yet understudied urban water sector. Knowing how urban irrigators use water is critical for projecting future demands, planning diverse supply portfolios, and designing conservation strategies. In this study, we developed a holistic, analytical approach to advance knowledge about the temporal and spatial dimensions of nonresidential outdoor water use, also known as large landscape irrigation. Our approach employed data from two forthcoming technologies: dedicated irrigation meters and smart meters (i.e., advanced metering infrastructure). We then applied our methodology to a case study city in the San Francisco Bay Area, California, from 2013 to 2016 during a historic, high-profile drought. Importantly, we uncovered behavioral differences between customers with potable versus recycled water connections and different subsectors of large landscape irrigation. Overall, conservation patterns mimicked those across California. Although they saved at lower rates, customers with recycled water followed similar conservation trends despite receiving no mandates. A weekly water use model revealed drivers of water demand, while spatial analyses showed hot and cold spots of conservation, with those in higher-income areas conserving less as the drought progressed. A conditional inference tree partitioned diverse customers based on their conservation rates, identifying characteristics of customers who could provide the most savings in future droughts. As increasing water scarcity and population growth prompt water suppliers to optimize resources through supply diversification and demand-side management, large landscape irrigation presents one avenue for achieving those goals.