One portion of the high level aqueduct was originally built by Herod the Great (37-4 B.C.) and then added on to during the days of the emperor Hadrian (ca. A.D. 130). The original Herodian aqueduct was about 5.5 mi. [9 km.] long and gathered water from the springs near Shuni - to the north northeast of Caesarea, near the foot of Mt. Carmel. Hadrian expanded it even further in his effort to provide Caesarea with additional water.
There were additional rebuilds during the times of the Roman, Byzantine (ca. 22 B.C.-A.D. 639) and Crusader (12th century) cities.