Which of the following actions contributes most significantly to the conservation of water at home?

Using water-efficient appliances is the most significant action for conserving water at home because these appliances are designed specifically to minimize water usage while still delivering effective performance. For instance, modern washing machines and dishwashers can use substantially less water than older models, often incorporating technologies such as smart sensors and efficient cycle options that optimize water use based on load size or soil level. This can lead to considerable water savings over time, especially in households that run these appliances regularly.

In contrast, actions such as taking longer showers, running the tap while brushing teeth, or using a garden hose for cleaning typically lead to increased water consumption. Long showers may use several gallons of water unnecessarily, running the tap while brushing can waste gallons as well, and using a garden hose without a spray nozzle can lead to significant water runoff compared to more controlled methods of cleaning. Thus, investing in water-efficient appliances has a far greater impact on reducing overall water usage in the home.