The two banks of Jerash Valley set the boundaries of the catchment area of rainfall that is collected to cover the city needs. During the Roman Era, as the Jerash city became more and more prosperous and flourishing as agricultural and trade center, the standard of living rose and so did the private consumption, bath houses, fountains, etc. Subsequently the need for a more abundant water supply rose too. In total the remains of seven bathhouses (plus one in Birketein), one nymphaeum and numerous fountains have been found until now. Apart from that, there were many cisterns fed by rainwater harvesting.
The Ain Karawan spring
Ain Karawan is a strong perennial spring lying within the city walls of Jerash, that still runs today! However it lies almost in the bed of the valley, at an altitude too low to provide water to the great temples, fountains, etc. on the west side.
The Birketein pools
Water was, therefore, channelled from a large double reservoir at Birketein, a spring (named after the double reservoir) at a higher level at a distance approximately 1200 m to the north of the city centre. Birketein double pools had been, thus, an important component of the water management system of Jerash. Several springs fed the Birketein reservoirs (Shawahid, Deer Ellayat and Ain Souf) and this water was then used either for furnishing the fountains or for farming.
The Birketein reservoir has a rectangular shape and was divided into two pools by a barrier wall. It is 43,5 m wide, 88,5 m long and some 3 m deep. Originally a colonnade, which can be dated to 209 AD, ran along the western side framing the ancient processional way, which was lined with funerary monuments, from the northern gate of Gerasa via the Birketein pools to the Tomb of Germanus, some 100 m to the north.
The double pools, as well as the nearby theatre were built using harsh limestone that is available in the region.
In the western, northern and eastern corners of the pool there are 8-step stairs that give access to its bottom used for the purposes of cleaning and repair of the gates or channels in the walls.
Birketein was a luxury ′suburb′ including a small theater, at the same time a cult place for the Maiuma(s) annual nautical festival which involved, among other festivities, the ritual submersion of naked women.
The Al- Birketein reservoir continues to be used until our days! The two pools are used as a water-resort area for the kids in spring time and by the farmers living downstream. Only in late summers the two pools become empty due to evaporation.
According to a recent local study there are three possible reasons for constructing the double pools:
- According to inscriptions dating to the 6th century AD the pool had been used for celebrations of the Mayomas water festival. The festival was later considered scandalous with the arrival of Christian religion and was gradually abandoned.
- This large pool fed by the Karawan spring was the most important source of water supply for the western part of the city of Jerash.
- Romans may have used it also for water games.
The aqueduct leaving from Birketein fed several major installations on the western bank of the river, including the West Baths, the nymphaeum and one of the fountains in the macellum, and probably the lion-headed fountain in the northern gates (tetrapylon).
The lavish nymphaeum of Jerash dedicated to the nymphs was constructed in 191 AD. Such fountains were common in Roman cities, and provided a refreshing focal point for the city. The fountain was originally embellished with marble facing on the lower level, painted plaster on the upper level, and topped with a half-dome roof, forming a giant niche. Water cascaded through seven carved lion’s heads into small basins on the sidewalk.
The massive West Baths, on the right of the Birktein pools, covered an area of 50 x 70 m and now lie where they fell after the earthquake of 749 AD. Typical of the 2ndcentury, the Baths were an imposing complex of hot and cold rooms and other facilities. The East Baths may also have been fed by Birketein rather than Ain Karawan.
Two other fountains were added to the macellum in the later 2nd early 3rd AD century and between the 3rd to 5th centuries AD respectively. Domestic water supply seems to have relied on wells and rainwater cisterns; no connection has been found to the piped distribution network. Similar to the rest of the city, we know of no additions or changes to the water management system until the 5th century AD when the Baths of Placcus, including a public latrine, were built between the Temple of Artemis and the Church of St. Theodore.
The aqueduct seems to have been supplemented by rainwater stored in cisterns, particularly in the areas of the Temple of Artemis, the south decumanus and the oval plaza. The drainage network which had a 5th-order collector under the cardo, as well as lower order drains in the side streets, may also date to this period.
Because of the local terrain conditions a siphon must have been part of the arrangement. However, until now no concrete remains have been found that can confirm this hypothesis. On the other hand, only a small part of an aqueduct structure have been found between the Ain Karawan spring and the eastern bathhouse.