Which aspect of stormwater management does a retention basin primarily address?

A retention basin primarily addresses the aspect of water retention time. Retention basins are designed to collect and hold stormwater runoff, allowing it to infiltrate into the ground or evaporate over time. This process effectively reduces the overall volume and rate of stormwater discharge into nearby waterways, helping to manage how long water remains in the basin before it is released.

By allowing water to remain for an extended period, retention basins also offer an opportunity for sedimentation and pollutant removal, which can contribute indirectly to water quality improvement. However, the primary function of these basins is focused on extending the retention period of water, which helps in managing both the quantity of water that leaves the basin and reducing the risk of flooding downstream. This contrasts with other control methods that specifically target flooding prevention or directly address soil erosion. Thus, water retention time is a central aspect of the function and effectiveness of retention basins in stormwater management.