What does stormwater retention refer to?

Stormwater retention refers to the difference between precipitation and runoff, which highlights how much water can be captured and held in a designated area after rain events. Understanding this concept involves recognizing the role of impervious surfaces, soil characteristics, vegetation, and the design of the landscape in managing rainfall.

When rainfall occurs, not all of the water will infiltrate the ground or be absorbed; some will move over the surface as runoff. Retention practices, therefore, aim to reduce this runoff by capturing and holding water, which helps to prevent flooding, recharge groundwater, and improve water quality.

While the other options relate to aspects of stormwater management, they do not accurately define stormwater retention. The absorption of water by soil pertains to infiltration, total precipitation refers to the overall amount of rainfall, and runoff specifically describes water that flows over surfaces rather than being stored. Hence, the distinction of stormwater retention being the difference between precipitation and runoff captures the concept accurately in the context of managing stormwater effectively.