Where does rain go when it falls on the road?

Have you ever stood under an umbrella and listened to rain pattering on the street? Splish, splash, the road turns dark and shiny. Yet even in a big storm, the road never fills up like a swimming pool.

So where does all that rain go when it falls on the road? Let's follow one tiny raindrop and find out.

Our raindrop lands on the road and cannot sink in. The road is hard and smooth, with no tiny gaps for water to slip into. So the water stays on top and starts to move.

The road bulges up a little in the middle and dips down at both edges. Water always rolls downhill, so our raindrop slides toward the side of the road.

At the edge, the raindrop reaches the gutter, which is the low channel running along the side of the road next to the curb. The gutter gathers water from its whole side of the road. Lots of raindrops join together there and make a little stream.

The gutter slopes gently too, so the little stream trickles along it, past parked cars and front gates. More water joins in as it goes. Where do you think this busy little stream is heading?

It is heading for a storm drain, which is a hole at the edge of the street with metal bars across the top. The gaps between the bars let water fall through and keep big sticks out. Down the raindrop goes, splash!

Under the street, the storm drain opens into wide pipes that run beneath the roads like hidden tunnels. The pipes slope downhill, so the water keeps flowing all by itself. Water from many storm drains across the town meets inside them.

At the end of the pipes, the water pours out into a stream or a river. From there it flows on with the river, toward a lake or the sea. The rain from your street now travels with all the other water out in the world.

Gutter, storm drain. The hard, sloping road sends the rain into the gutter, then down a storm drain and through pipes under the street to a river, a lake or the sea.

Next time you hear rain on the street, you will know just where every drop is going.