Why Is Residential Irrigation So Hard to Optimize?

Abstract

Irrigation of residential landscapes is one of the largest demands for municipal water suppliers. However, it is often done inefficiently and is a concern for limited capacity and low pressure. Why, really, is residential landscape irrigation so inefficient, and why is it so difficult to optimize? The problem, as we suggest framing it, comes down to four C’s: conditions, components, controls, and customers. The conditions for efficient irrigation are too complex, sprinkler components are too imprecise, sprinkler controls too simplistic, and most water customers are too untrained as irrigators. Any management system with so many weaknesses is sure to be inefficient. Better plant choices, better landscape layouts, and precision irrigation technology are obvious solutions. Beyond these solutions, we recommend further development of smart irrigation controllers that account for the complexity of irrigation conditions and allow remote control by the water supplier. For an incentive, owners can opt-in and occasionally have their irrigation delayed or skipped if the water supplier needs to shed demand. We call this an “integrated water distribution system” where one benefit is a discretionary water demand that can be coordinated between suppliers and customers.

Transforming Great Salt Lake from Afterthought to Asset

“…Because consumptive water use is the culprit [5,6], we need strategies to reduce consumptive water use upstream-ideally without losing the intended benefits-and leave more water available for the lake. One prime candidate is residential landscape irrigation, which recent studies show can be done far more efficiently even without changing the landscapes [9,10]; another is agricultural irrigation, where Utah has a well-funded program for water optimization [11,12]. Utah has had water conservation goals since 2000, and a 2019 update revised them to capture new technologies, policies, and regionally specific opportunities [13].…”