Definition

Noun: A retention basin is a type of water storage facility or structure designed to collect and hold stormwater runoff. Unlike some similar structures, the water collected in a retention basin is permanently held and prevented from flowing further downstream. Its primary purposes are to control flooding, improve water quality by allowing sediments and pollutants to settle, and often to recharge groundwater.

Usage

Retention basins are a common feature in urban planning, civil engineering, and land management. They are used to manage surface water from rainfall or snowmelt, especially in developed areas with many impervious surfaces like roads and rooftops.

Examples

• The new housing development includes a large retention basin to handle stormwater from the neighborhood.
• Engineers designed the retention basin to permanently hold a certain volume of water to prevent downstream flooding.
• The water quality improved after the city constructed a retention basin that allowed pollutants to settle out.

Advanced Usage

• Ecological Design: Modern retention basins are sometimes designed as "wet ponds" or "stormwater wetlands" that incorporate vegetation. These not only manage water but also provide habitat and enhance the landscape.
• Maintenance: Proper maintenance of a retention basin, such as removing accumulated sediment, is crucial for its long-term effectiveness and flood control capacity.

Variants and Related Words

• Detention Basin (n): A similar storage site for stormwater, but it is designed to temporarily hold water and then release it slowly through an outlet structure. The key difference is that a detention basin is meant to drain completely between rain events, while a retention basin holds water permanently.
• Stormwater Pond (n): A general term that can encompass both retention and detention basins.
• Sedimentation Basin (n): A basin primarily designed to capture sediment from runoff, which is a key function of many retention basins.

Synonyms

• Wet Pond
• Stormwater Retention Pond
• Permanent Pool Basin

Antonyms / Contrasting Terms

• Detention Basin: (As defined above, for contrast in function).
• Infiltration Basin: A basin designed to allow water to soak directly into the ground, rather than being permanently stored on the surface.

Noun

1. a storage site similar to a detention basin but the water in storage is permanently obstructed from flowing downstream