Many high-performing, water-saving fixtures and appliances are designed like straws, supplying only enough water to satisfy one’s thirst. But the pipes that bring that water into Americans’ homes are sized more like fire hoses. Oversize plumbing pipes move water inefficiently, wasting money and increasing the risk of waterborne diseases. And water efficiency is especially important as climate change makes droughts more frequent and severe. Efforts to right-size plumbing pipes to match the intake of water-saving products are slowly gaining traction, but homeowners and designers of multiunit properties who want to use these more sustainable pipes need to demand them during the project design phase.