A retention basin is a facility designed to hold stormwater, often relying on infiltration, evaporation, or reuse rather than routine discharge.
Definition
A retention basin is a stormwater facility intended to hold water for a defined period, often allowing it to infiltrate, evaporate, or be reused rather than routinely releasing it through an outlet. The actual function depends on soil, groundwater, basin design, climate, project criteria, and applicable local definitions. A firm's work may include evaluating site suitability, estimating storage, coordinating grading and drainage, and documenting maintenance needs. The word can be used differently across jurisdictions and project documents, so the intended operation should be specified. A retention basin is not simply any basin that temporarily stores runoff; stormwater detention typically describes storage with a controlled release. A retention basin also does not guarantee that all water will infiltrate or that overflow will never occur. The design basis and operating responsibilities shape what it can accomplish.
How owners use it
- Describe a facility intended to hold stormwater for infiltration, evaporation, or reuse.
- A basin holds 18,000 gallons and infiltration removes 6,000, leaving 18,000 - 6,000 = 12,000 gallons before other losses or inflows.
- Assess whether soil, groundwater, and site conditions support the intended basin function.
- Clarify overflow routing, inspection, and maintenance responsibilities in project records.
