How do Best Management Practices (BMPs) reduce the volume of stormwater runoff?

Best Management Practices (BMPs) play a crucial role in managing stormwater runoff, primarily by promoting infiltration and reducing the rate of runoff. BMPs are designed to mimic natural processes and improve the earth's ability to absorb and filter water. This is achieved through various techniques such as creating vegetated swales, rain gardens, permeable pavements, and other green infrastructure methods that enhance the ground's ability to soak up rainfall.

By promoting infiltration, BMPs help recharge groundwater supplies, reduce the volume of stormwater that flows over impermeable surfaces, and diminish the likelihood of flooding and erosion. They also aid in removing pollutants from the stormwater before it reaches waterways, thereby improving water quality. The overall effect is a reduction in the quantity of runoff entering storm drains and natural water bodies, which mitigates negative environmental impacts.

In contrast, options that involve increasing impermeable surfaces or preventing vegetation would lead to more runoff, as they do not facilitate water absorption. Directing runoff to natural bodies of water without proper treatment can also pose risks to water quality, making the promotion of infiltration a fundamental principle of effective stormwater management.