How can we make better use of rainwater? Right now, engineers all around the world are grappling with this very challenge. Rainfall patterns are shifting; in general, rain is falling less frequently but more intensely. Our changing climate is causing traditionally wet areas to be much wetter and more likely to flood, and it’s turning dry areas into places with lengthy droughts.

Changes in rainfall are revealing other problems. One is that our cities and suburbs are not built to allow rain to follow a natural course. When rain falls moderately and predictably, our storm drains, ditches, and pipes channel rainfall (and other forms of precipitation) without much problem. But these human-made channels don’t recharge aquifers—the permeable layers of rock that hold and filter groundwater. So when huge amounts of rain fall suddenly, flash floods and landslides overwhelm human systems. We are also not prepared to salvage as much rain as possible in places where very little is falling and much of the year has no rain at all.

There’s a lot we can do to use rain for our benefit while lessening its destructive power. After all, we depend on rain! Engineers are learning new ways to manage it by observing natural processes. They are designing porous concrete, rain gardens, swales, and bioretention ponds, among other inventions. And there’s a lot we can do to make better use of scant rain, like harvesting fog.

Your challenge: Identify a problem involving rainfall in your community and design a solution to address it.