What strategy is recommended to manage the runoff from frequent small rain events?

The recommended strategy for managing runoff from frequent small rain events is to capture and treat the first flush. This approach is particularly effective because the initial portion of stormwater runoff often contains the highest concentration of pollutants washed from surfaces such as streets, roofs, and parking lots. By capturing this first flush, you can significantly reduce the amount of contaminants entering waterways, thus improving water quality.

Implementing techniques such as bio-retention, rain gardens, or constructed wetlands allows for the treatment of the first flush. These systems provide filtration and biological processes that help to cleanse the water before it discharges into storm systems. Managing these frequent small events is crucial because they collectively contribute to overall water quality issues over time and can exacerbate erosion and flooding if not properly managed.

The options that suggest increasing impervious areas, relying solely on sedimentation basins, or ignoring small rain events do not provide sustainable or effective solutions for stormwater management. In fact, increasing impervious surfaces generally leads to greater runoff and pollutant loads, while neglecting small rain events accumulates issues that can impact larger stormwater management strategies.