Name three strategies to mitigate flood risk in drainage basins and briefly describe them.

Name three strategies to mitigate flood risk in drainage basins and briefly describe them.

• A. Detention reservoirs to store excess water; green infrastructure to enhance infiltration; floodplain zoning and channel improvements.
• B. Only building higher levees.
• C. Damming every tributary.
• D. Planting trees in unrelated sectors.

Answer: (A)

Managing flood risk in drainage basins relies on combining storage, infiltration, and conveyance improvements to slow, store, and safely move water during storms. The best option reflects that mix: detention reservoirs to store excess water; green infrastructure to enhance infiltration; floodplain zoning and channel improvements. Detention reservoirs temporarily hold runoff, which lowers the peak flow and buys time for water to be released gradually or infiltrate. Green infrastructure—like bioswales, rain gardens, and permeable pavements—works on the landscape to increase infiltration and reduce the volume of runoff, helping to keep water on the surface longer but at manageable levels. Floodplain zoning and channel improvements reduce risk by preventing development in high-risk areas and by increasing the channel’s capacity to convey water, which helps prevent excessive flood depths and erosion downstream. Together, these strategies address storage, infiltration, and flow conveyance, providing a more resilient approach than relying on a single measure. Relying only on higher levees misses the opportunity to reduce overall runoff and can shift risk downstream; damming every tributary is impractical and environmentally disruptive; planting trees in unrelated sectors won’t specifically mitigate basin-wide flood risk.

Managing flood risk in drainage basins relies on combining storage, infiltration, and conveyance improvements to slow, store, and safely move water during storms. The best option reflects that mix: detention reservoirs to store excess water; green infrastructure to enhance infiltration; floodplain zoning and channel improvements. Detention reservoirs temporarily hold runoff, which lowers the peak flow and buys time for water to be released gradually or infiltrate. Green infrastructure—like bioswales, rain gardens, and permeable pavements—works on the landscape to increase infiltration and reduce the volume of runoff, helping to keep water on the surface longer but at manageable levels. Floodplain zoning and channel improvements reduce risk by preventing development in high-risk areas and by increasing the channel’s capacity to convey water, which helps prevent excessive flood depths and erosion downstream. Together, these strategies address storage, infiltration, and flow conveyance, providing a more resilient approach than relying on a single measure. Relying only on higher levees misses the opportunity to reduce overall runoff and can shift risk downstream; damming every tributary is impractical and environmentally disruptive; planting trees in unrelated sectors won’t specifically mitigate basin-wide flood risk.