impluvium

An impluvium is a shallow basin located in the interior of the atrium in a traditional Roman house (domus). It collected rainwater that entered through the roof’s opening, the compluvium, and directed the water into the basin below. The basin was typically a recessed feature in the floor, often made of stone or plaster and lined with waterproof material. An overflow channel or drain carried excess water away, usually into a subterranean cistern or drainage system, or out to the street.

The impluvium was part of a broader rain-water management system in the Roman domus. The roof opening supplied rainwater to the basin, while the surrounding atrium served as a light and air well for the house. In many houses the water collected in the impluvium would be stored in a cistern or used for non-potable tasks such as washing and cleaning; drinking water was typically sourced from wells, public fountains, or private cisterns.

The term impluvium is Latin in origin, as is its companion term compluvium, which denotes the roof opening that admits rain. Impluvia vary in size and decoration; some basins were simply functional, while others were lined with mosaic or decorated with painted plasters, reflecting the household’s status or taste. The feature is most closely associated with urban Roman domus of the Republic and early Imperial periods, though its use and design could vary by region.