What approach uses landscaping features like islands and swales to manage stormwater?

The correct choice is bioretention, which refers to a stormwater management practice designed to capture and treat runoff. This method utilizes landscaped areas, such as islands and swales, that incorporate vegetation, soil, and sometimes engineered media to improve water quality and manage stormwater quantity.

In bioretention, these features work by allowing stormwater to infiltrate into the soil where pollutants can be filtered out and absorbed by plants. The design typically includes a shallow depression that collects runoff, promoting evaporation and transpiration, while also reducing the volume of water that reaches storm sewer systems. This sustainable approach not only addresses stormwater management but also enhances the aesthetic and ecological value of urban and suburban landscapes.

The other choices do not align with this concept. Backfill relates to the process of refilling an excavation site and is not directly related to stormwater management. The angle of repose pertains to the steepest angle at which loose material can rest without sliding, which is relevant to soil stability but not specifically tied to stormwater practices. Bearing capacity refers to the ability of soil to support the loads applied by structures and is crucial for foundation design rather than stormwater management techniques.