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.