Which of the following is an impervious surface example?

• A. Grass lawn
• B. Wood deck
• C. Concrete and asphalt
• D. Permeable pavers

Answer: (C)

Impervious surfaces are materials that prevent water from soaking into the soil, so rainfall becomes runoff instead of infiltrating. Concrete and asphalt are classic impervious surfaces because they’re dense, nonporous paving materials that water can’t pass through. A grass lawn is permeable; water infiltrates the soil and is taken up by plants. Permeable pavers are designed to let water flow through their joints and into the ground below, so they’re not impervious. A wood deck is a solid surface that generally doesn’t allow infiltration, but the most clear and widely recognized impervious example among these options is concrete and asphalt.