What is stormwater management and why is it important in site design?

• A. Increasing impermeable surface area to direct water
• B. Practices to control runoff, reduce flooding, and protect water quality
• C. Eliminating vegetation to simplify drainage
• D. Maximizing drainage into municipal sewers only

Answer: (B)

Stormwater management is about controlling how rainwater on a site becomes runoff and how that runoff is captured, treated, and released in a controlled way. The goal is to prevent flooding, reduce erosion, and keep downstream water bodies clean by removing pollutants and limiting sediment. In site design, this means planning for gradual, infiltrated drainage rather than letting water rush off impervious surfaces. On-site strategies include reducing impervious cover, using permeable paving, preserving vegetation, and incorporating features like bioswales, rain gardens, retention or detention ponds, green roofs, and rainwater harvesting. These practices slow the movement of water, promote groundwater recharge, and improve water quality before the runoff leaves the site. Approaches that increase impermeable area, remove vegetation that stabilizes soil and filters pollutants, or push everything into the municipal sewer system without treatment would worsen flooding and water quality issues, so the on-site, integrated management approach is the strongest fit for sound site design.