Residential inground irrigation systems are prevalent across the United States and beyond for lawn maintenance. With the postwar rise of suburban development across the U.S. in the 1940s and 1950s, sprinklers became a common sight. Today’s technology includes smart controllers. Climate change and particularly the ongoing western United States megadrought are driving legal changes and improvements to water infrastructure. On average Americans devote around 40% of residential water use to watering their lawns with southwestern United States using far higher percentages. Would more efficient allocation of water using smart controllers offer a solution to water woes in the American southwest?
Researchers Nathan T. Lunstad and Robert B. Sowby performed a literature review encompassing more than 80 studies on residential applications of smart irrigation controllers. Their research covers studies in three countries (United States, Canada, and Australia) and focuses on several irrigation control technologies (manual, timer, rain sensor, soil moisture sensor, evapotranspiration, and weather-based irrigation controller). In their paper “Smart Irrigation Controllers in Residential Applications and the Potential of Integrated Water Distribution Systems,” the authors reviewed various studies to access effectiveness and potential water savings opportunities. Find out which paired sensors were the most effective and how these smart irrigation controllers can address water scarcity in the Journal of Water Resources Planning and Management at https://doi.org/10.1061/JWRMD5.WRENG-5871. The abstract is below.
Drought and population growth, especially in the western United States, are propelling a need for more efficient irrigation. Smart irrigation controllers, which interface with soil moisture, evapotranspiration (ET), or weather sensors, have been promoted as a demand-side management tool for this purpose. This paper reviews the body of research on residential smart irrigation controllers and their effectiveness. We find that smart irrigation controllers consistently reduce water demand by 15% among general users and more than 40% among indulgent users. Gaps in research include studies addressing peak demand reduction, centralized communication, data verifiability, and human factors of landscape management. Future work may develop techniques for coordinating networks of smart irrigation controllers to enable greater shifting and shaving of discretionary irrigation demands, similar to what is already happening in the electric grid, thereby creating an integrated water distribution system (IWDS). An IWDS may utilize smart irrigation controllers as direct load control devices at customer end points and interface with advanced metering infrastructure (AMI) and supervisory control and data acquisition (SCADA) systems at a central location to create more effective demand-side management (DSM) strategies for water conservation.
Explore the potential that networking residential irrigation systems could have on water management in the ASCE Library: https://doi.org/10.1061/JWRMD5.WRENG-5871.