What are impervious surfaces?

Impervious surfaces are things that stop water from going through them, like a big, solid blanket on top of the ground.

Imagine you're playing in the rain with your favorite puddle. Now imagine someone covers that puddle with a really thick, waterproof mat, no more splashing! That’s what impervious surfaces do to the ground. They’re like that mat, and they stop rain from seeping into the soil below.

Think of your kitchen floor. If you spill water on it, the water just rolls around or maybe soaks in a little, but most of it stays on top. That’s because kitchen floors are made of materials that don’t let water pass through easily, like tiles or linoleum.

Impervious surfaces are usually things like:

• Concrete
• Asphalt
• Brick
• Tiles

These are all hard, flat materials you might see on streets, parking lots, and sidewalks. They’re great for walking and driving, but not so great for letting water go through.

So next time it rains, think about how the water behaves on different parts of your playground, some spots get muddy, others stay dry and slick! That’s the work of impervious surfaces.