AQUEDUCT. A channel, covered or open, cut in the rock; a waterway built of stone and sometimes faced with smooth cement; a waterway carried on stone arches across depressions; used to convey water from reservoirs, pools, cisterns, or springs to the places where it is to be used. Aqueducts may have existed even in pre-Israelite times, and continued to be developed until the excellent work of the Nabatean period (100 b.c. to a.d. 100). The Roman period shows many fine examples. Hezekiah excavated the Siloam tunnel (conduit) to bring water into Jerusalem by a way that could not be stopped up in time of siege (2Kgs.20.20; 2Chr.32.30), and this served the purpose of an aqueduct.