Which practice increases flood risk by preventing water infiltration?

Which practice increases flood risk by preventing water infiltration?

• A. Planting trees
• B. Paving
• C. Undisturbed soil
• D. Mulching

Answer: (B)

Water infiltration is when rain soaks into soil. Paving creates an impermeable surface that blocks infiltration, so rain becomes surface runoff instead of soaking in. This quick runoff flows into streams and drains faster, raising peak flows and the chance of floods, especially during heavy rain events. In contrast, planting trees, keeping soil undisturbed, and applying mulch all promote infiltration and water storage in the soil, reducing runoff and flood risk.

Water infiltration is when rain soaks into soil. Paving creates an impermeable surface that blocks infiltration, so rain becomes surface runoff instead of soaking in. This quick runoff flows into streams and drains faster, raising peak flows and the chance of floods, especially during heavy rain events. In contrast, planting trees, keeping soil undisturbed, and applying mulch all promote infiltration and water storage in the soil, reducing runoff and flood risk.