reservoir

A natural or artificial rock-cut storage container for the collection of rainwater. Such installations, variously called reservoirs, pools, or cisterns, were essential for settlements relying almost totally on winter rains for their water source. Even sites located close to a spring augmented their water supply by such collection methods. Kings constructed cisterns to hold water for times of siege (2Kgs 20:20) and for agriculture (2Chr 26:10), and great rock-cut pools are referred to at Hebron (2Sam 4:12), Samaria (1Kgs 22:38), and Gibeon (2Sam 2:13).