A large natural or an artificial underground space enhanced to store large quantities of water, primarily for drinking, is known as a reservoir. Water storage is essential to life in regions where there is no rainfall during part of the year and the total amount of precipitation is low enough to require conservation of water from one period to the next: winter to summer, night to day, and a rainy year to a drought year. Syria-Palestine abounds with reservoirs created for this purpose.
Reservoirs were either hewn from natural rock or built of stone; sometimes both engineering methods were combined. In several cases, large supporting pillars were constructed to hold up the installation's ceiling. The walls were thickly plastered, usually with a layer 5–10 cm thick, to prevent loss of water from percolation.
The earliest reservoirs discovered in the region are small and should properly be designated cisterns. The earliest reservoir in the land of Israel was discovered at Hazor and dates to the Middle or Late Bronze Age. [See Hazor.] This reservoir, located beneath a Canaanite palace, is shaped like a cross or a clover leaf and is coated with white plaster. The water entered the reservoir by means of a monumental drain made of basalt. Its volume is 150 cu m.
Two reservoirs for the collection of runoff are known from the Iron Age II period: at Beth-Shemesh, at Eitam, and at Beersheba. [See Beth-Shemesh; Beersheba.] The reservoir at Eitam is a system of natural caves whose volume is 240 cu m. The Beth-Shemesh reservoir is hewn out of soft, chalky rock; it is square and has four extensions and a capacity of 500 cu m. Both reservoirs display a double layer of plaster, one gray and the other yellow. The one at Beersheba has a volume of about 600 cu m and the plaster is similar to the one at Beth-Shemesh.
During the Second Temple period (Hellenistic and Early Roman periods) several reservoirs were cut out of the rock to serve the desert fortresses at Sartaba (nine reservoirs with a total capacity of 5,000 cu m), Duk (Dagon/Mt. Quarantale; nine reservoirs with a capacity of about 2,000 cu m), Cypros (four reservoirs, one with a volume of 500 cu m), Hyrkania (twenty-four reservoirs with a capacity of 20,000 cu m), Herodium (four reservoirs), and Masada (twelve reservoirs with a volume of 40,000 cu m). [See Herodium; Masada.] The water reached the reservoirs by means of conduits or aqueducts that either diverted water from flash floods, collected runoff, or conveyed water from natural springs, such as at Cypros (phase II).
Also from the Second Temple period are the thirty-four reservoirs beneath the Temple Mount in Jerusalem, whose total capacity is 36,000 cu m. The largest of these, with a volume of 12,000 cu m, located not far from the al-Aqṣa mosque, is called the Small Sea; it is the largest ancient reservoir in the region. [See Jerusalem.]
In the Roman and Byzantine periods, many more reservoirs were hewn or constructed. At Sepphoris, a sausage-shaped reservoir was hewn from the rock with a volume of 4,300 cu m (see figure 1). [See Sepphoris.] A reservoir at Beit Ras (Capitolias) in Jordan has a similar shape and size to the one found in Sepphoris. [See Beit Ras.] In Jerusalem, the domed reservoir of the Nea Church, built of two longitudinal galleries and two cross galleries, has a total volume of 3,500 cu m (its wall has an inscription dating it to the reign of Justinian). The built reservoir at Tiberias has a volume of 2,000 cu m; and the partly hewn and partly constructed reservoir at Hippos/Susita has a volume of 1,500 cu m. [See Tiberias.] These large reservoirs were fed by aqueducts, with the exception of the ones in Jerusalem. In the Byzantine period, large reservoirs were built for the monasteries in the Judean Desert. The Martyrius monastery has a reservoir of 2,000 cu m; the Haritun monastery has a reservoir of 1,000 cu m and walls decorated with crosses.
In the Early Arab period, four underground reservoirs were built in the city of Ramla (the Pool of Arches and three located next to the White Mosque). [See Ramla.] These were fed by an aqueduct that originated at Tel Gezer; their total volume is 10,000 cu m. Numerous pillars support these reservoirs' ceilings. In the Crusader period, reservoirs were built inside fortresses to collect runoff; especially well known are those at Qal῾at Nimrod and Belvoir (Kokhav ha-Yarden). In the Ottoman period a large reservoir was built at Acre/Akko underneath the courtyard of the Jazzar mosque, which had been a Crusader church. This reservoir was the terminal point for the Kabri aqueduct. [See Akko; Kabri, Tel.]
- ῾Amit, David, et al., eds. The Aqueducts of Ancient Palestine (in Hebrew). Jerusalem, 1989.
- Brinker, Werner. “Antike Zisternen: Stationen ihrer Entwicklungsgeschichte.” Mitteilungen: Leichtweiss-Institut für Wassėrbau der Technischen Universität Braunschweig 103 (1989): 247–279.
- Heker, M. “Water…in Jerusalem in the Ancient Period” (in Hebrew). In Sepher Yerushalaim, edited by Michael Avi-Yonah, pp. 191–218. Jerusalem and Tel Aviv, 1956.
- Tsuk, Tsvika. “The Aqueducts to Sepphoris.” Master's thesis, Tel Aviv University, 1985. In Hebrew with an English summary.
Translated from Hebrew by Ilana Goldberg