IV. The water supply and drainage systems of the Wadi al-Farasa East
Most of the water coming from above to the eastern flank of Wadi al-Farasa East is collected in the huge cistern (B 16) on the upper terrace, the rest joins system A on the valley’s bottom. The rock above the triclinium shows careful planning against any loss of water that would otherwise escape towards the lower terrace: There is a series of retaining walls with hydraulic mortar (B 14, B 15) as well as a water channel running horizontally in front of them in order to absorb water that would not be retained by the walls. From the basins in front of the big cistern there must be a water channel feeding a small cistern in front of the „Garden Triclinium“ From the level of the „Garden Triclinium“ there is a rock-cut water pipe bringing water to a cistern on the lower terrace. The first meters of this channel are no longer visible but they can easily be deduced from the still visible rock cuttings (B 21) above the windows of the triclinium which then decline sharply and leading down into a cistern that is now buried under sand and stones (B 23) Considering this water channel we have to come back on our statement that no such system would lead above the triclinium; see Schmid 2000: 342. . Into the same cistern leads another water channel coming from the northern part of the flank were another cistern is cut into the rock (B 22). This cistern is fed from channels coming from above and shows some of the typical features of Nabataean hydraulic systems known in Petra. Usually such cisterns have more than one incoming or outgoing lines, often several. Most of the cisterns of the Wadi al-Farasa East are filled by several water pipes coming from the western flank of Jabal al-Madhbah and they have at least two outgoing pipes, one following the general direction of the main channel and one leading towards the bottom system (A) of the valley. Cistern B 22 too has two outgoing pipes, one reaching the above-mentioned cistern (B 23) and a second reaching one of the main water channels of the area (B 27) that leads from the lower terrace of the Wadi al-Farasa East to the huge cistern at the entrance of the valley (B 28) where also the water coming from the northern part of the western flank of Jabal al-Madhbah is collected.
Fig. 21: Schematic drawing of water supply and drainage systems in Wadi al-Farasa East (drawing: S. G. Schmid)
We will focus in this report just on the area above the triclinium on the lower terrace of the Wadi al-Farasa East in order to illustrate the ingenuity Nabataean engineers and planers in order to assure a smooth functioning of the city (Fig. 22–24).
Fig. 22: Schematic drawing of water supply and drainage systems on the E flank of lower terrace (drawing: S. G. Schmid)
The Wadi al-Farasa East with its manifold installations disposed of a highly sophisticated and complicated system for water supply but also for water drainage in order not to damage the rock-cut as well as the stone built monuments On Nabataean water supply systems in a wider context see Oleson 1992; 1997; Muheisen 1990. . In the Wadi al-Farasa East and probably in many other small and bigger valleys in the Petra area, these systems are tripartite (Fig. 21). There is one system (A) in the valley proper that collects the water on the deepest point of the overall system; a second system (B) covers one side wall of the valley and a third system (C) covers the other side wall of the valley. In the Wadi al-Farasa East the system (A) at the valley’s bottom has since been covered to a large extend by a lot of sand. The only remains still visible are a series of huge retaining walls that are constructed with hydraulic mortar and must have been part of that system. The western side wall (system C), that is the one above the „Soldier Tomb“ has already been partially discribed above. The most interesting and also the most complicated installations are the ones on the eastern flank, that is the one leading up to the „High Place“ (system B). This system seems to have been part of a network of a long-distance water supply system, bringing spring water from the area of Ain Brak outside Petra to the central area of the city between az-Zantur and the Qasr el-Bint Lindner and Hübl 1997. .
Fig. 23: Southern part of E flank of lower terrace with water drainage and supply system (photo: S. G. Schmid)
It becomes clear from such evidence that the Nabataean authorities must have developed a very effective programme of urban planning in order to implement such huge infrastructural works. Further, it is obvious that the construction of monuments such as the „Soldier Tomb“, the triclinium and the courtyard between them must be seen as an integral part of an overall plan and execution. Large-scale operations like these and their maintenance needed strict control by the authorities because installations like these were part of the network on which a large and sprawling population depended. A breakdown or abuse in one part could have serious and immediate effects on other parts of the population.
Fig. 24: Northern part of E flank of lower terrace with water drainage and supply system (photo: S. G. Schmid)
The cistern B 23 cannot only be inferred by the two water channels leading into it but also by the rock carved niche between them. Very often the Nabataeans did put such niches containing the image of a deity in places where significant waterworks were installed. This became particularly evident during recent investigations in the Siq as well as on the el-Hubta water supply system Siq: personal communications by U. Bellwald and D. Keller; el-Hubta: Gunsam 1997. . The immense work in order to keep only a single part of the valley dry and to bring the water exactly to the points where it was needed makes it possible to estimate the total amount of engineering and planning that was needed to install the water supply and drainage systems of the entire Wadi al-Farasa East, itself being just a small part of the city of Petra.
Most of the water coming from above to the eastern flank of Wadi al-Farasa East is collected in the huge cistern (B 16) on the upper terrace, the rest joins system A on the valley’s bottom. The rock above the triclinium shows careful planning against any loss of water that would otherwise escape towards the lower terrace: There is a series of retaining walls with hydraulic mortar (B 14, B 15) as well as a water channel running horizontally in front of them in order to absorb water that would not be retained by the walls. From the basins in front of the big cistern there must be a water channel feeding a small cistern in front of the „Garden Triclinium“. From the level of the „Garden Triclinium“ there is a rock-cut water pipe bringing water to a cistern on the lower terrace. The first meters of this channel are no longer visible but they can easily be deduced from the still visible rock cuttings (B 21) above the windows of the triclinium which then decline sharply and leading down into a cistern that is now buried under sand and stones (B 23). Into the same cistern leads another water channel coming from the northern part of the flank were another cistern is cut into the rock (B 22). This cistern is fed from channels coming from above and shows some of the typical features of Nabataean hydraulic systems known in Petra. Usually such cisterns have more than one incoming or outgoing lines, often several. Most of the cisterns of the Wadi al-Farasa East are filled by several water pipes coming from the western flank of Jabal al-Madhbah and they have at least two outgoing pipes, one following the general direction of the main channel and one leading towards the bottom system (A) of the valley. Cistern B 22 too has two outgoing pipes, one reaching the above-mentioned cistern (B 23) and a second reaching one of the main water channels of the area (B 27) that leads from the lower terrace of the Wadi al-Farasa East to the huge cistern at the entrance of the valley (B 28) where also the water coming from the northern part of the western flank of Jabal al-Madhbah is collected.
