Which method is used for controlling the quality of surface runoff on a site?

The method used for controlling the quality of surface runoff on a site is referred to as stormwater management techniques. This approach encompasses a range of strategies and practices designed to manage the quantity and quality of stormwater runoff, ensuring that it does not adversely affect surrounding water bodies or human habitats.

Stormwater management techniques can include practices such as retention and detention basins, bioretention areas, permeable pavements, green roofs, and the use of vegetated filter strips. These methods focus on treating runoff to remove pollutants, reducing peak flow rates, and promoting the infiltration of water into the ground. By implementing these techniques, landscape architects and planners can effectively reduce the impact of surface runoff on the environment, prevent flooding, and improve water quality.

The other options do not specifically address the comprehensive approach needed for managing water quality effectively. Increased drainage may simply accelerate runoff without ensuring its quality. Cover and concealment could refer to aesthetics or construction methods, but do not focus on runoff management. Regular watering pertains to irrigation practices, which do not directly influence the quality of stormwater runoff. This distinction emphasizes why stormwater management techniques are the preferred choice for controlling runoff quality on a site.