Which of the following is a common method to control stormwater runoff?

Green roofs are a common method to control stormwater runoff because they incorporate vegetation and soil layers designed to absorb rainfall. This absorption reduces the volume of water that flows into storm drains and local waterways, minimizing the risk of flooding and water pollution. By capturing and using rainwater, green roofs also help to filter pollutants and provide a cooling effect, which can mitigate urban heat.

While other options like combined sewer systems are intended to manage wastewater and stormwater, they can lead to overflow issues during heavy rain. Paved surfaces tend to exacerbate stormwater runoff as they do not allow for water infiltration, leading to increased surface water flow. Septic systems are designed for wastewater treatment, not for managing stormwater.