Detention Basins

Definition

Detention basins are engineered structures designed to temporarily hold stormwater runoff, allowing for controlled release to reduce flooding and improve water quality. These basins play a crucial role in managing the impact of land use changes on hydrology by mitigating the effects of increased impervious surfaces and altered drainage patterns.

5 Must Know Facts For Your Next Test

1. Detention basins are typically designed to temporarily store stormwater during heavy rainfall events and release it slowly to prevent downstream flooding.
2. These basins can improve water quality by allowing sediments and pollutants to settle before the water is discharged into nearby waterways.
3. They are often used in urban areas where increased impervious surfaces lead to higher volumes of runoff, exacerbating flood risks.
4. Detention basins can be designed as either dry or wet ponds, with dry ponds being empty between storm events while wet ponds maintain a permanent pool of water.
5. Proper maintenance of detention basins is essential for their effectiveness, requiring regular inspections and sediment removal to ensure they function as intended.

Review Questions

• How do detention basins mitigate the impact of urbanization on hydrology?
  • Detention basins help manage the increased runoff generated by urbanization, particularly due to the presence of impervious surfaces like roads and buildings. By capturing and storing stormwater, these basins reduce peak flow rates during heavy rain events, thus decreasing the risk of downstream flooding. This controlled release allows for more natural hydrologic conditions, ultimately protecting waterways from sudden influxes of stormwater.
• Discuss the role of detention basins in improving water quality and how they achieve this.
  • Detention basins improve water quality by providing a space for stormwater runoff to settle before it enters local streams or rivers. As water sits in the basin, pollutants such as sediments, oils, and heavy metals can precipitate out or be absorbed by vegetation present in and around the basin. This natural filtration process helps reduce contamination in receiving waters, which is essential for maintaining healthy ecosystems.
• Evaluate the effectiveness of detention basins in managing stormwater runoff in areas with rapid development, considering both benefits and potential challenges.
  • Detention basins can be highly effective in managing stormwater runoff in rapidly developing areas by reducing flood risks and improving water quality. However, challenges arise in maintaining these basins due to increased sedimentation and pollution from construction activities. Additionally, if not properly designed or maintained, they may fail to handle extreme rainfall events caused by climate change, leading to potential overflow and inadequate flood protection. Balancing these benefits and challenges is crucial for effective stormwater management in urban settings.

Related terms

Stormwater Management: The practice of controlling the quantity and quality of stormwater runoff to prevent flooding and protect water resources.

Impervious Surfaces:

Surfaces that do not allow water to infiltrate, such as concrete or asphalt, which increase runoff and can lead to flooding.

Water Quality: A measure of the condition of water based on its physical, chemical, and biological characteristics, which can be affected by pollutants carried by runoff.