Which stormwater management component is essential for controlling runoff in urban development?

The essential component for controlling runoff in urban development is the stormwater conveyance system. These systems are designed to efficiently transport stormwater from paved surfaces or other impervious areas to appropriate discharge points. The primary function of a conveyance system is to manage the flow of water, preventing flooding and minimizing erosion by directing runoff in a controlled manner. This system includes infrastructure such as gutters, drains, and pipes, which work together to handle the increased water volume resulting from urbanization.

While retention basins, permeable pavements, and green roofs play significant roles in managing stormwater and mitigating its impacts, their functions are often more focused on retention, infiltration, or green infrastructure benefits rather than the direct management of water flow. Retention basins are effective at capturing and storing runoff, allowing for gradual release, while permeable pavements facilitate infiltration to reduce surface runoff. Green roofs can aid in absorbing rainwater and reducing runoff volumes. However, without a robust stormwater conveyance system to direct and manage the runoff appropriately, effective control in a densely developed area could falter.