II. Lower terrace – c. Water drainage system of the „Soldier Tomb“
One of the most important aspects of the Nabataean rock-cut facades is their dealing with the seasonal rainfalls. The very soft sandstone of Petra makes for easy carving of the monuments, but it is also easily eroded by wind and weather On Nabataean rock cut facades in general see Schmidt-Colinet 1981; McKenzie 1990; Zayadine 1997; Schmid 2000B, all with further references; on the erosion of the Petraean sandstone see Abu Safat 1986 and recently Heinrichs – Fitzner 1999. . In order to prevent the rock-cut monuments from erosion the Nabataeans applied two basic means:
Facades were covered by stucco (and sometimes painted)
A system was devised to prevent rain water flooding to reach the facades
There were two main methods by which the builders of these monuments tried to prevent water from running down the facades: Some monuments are cut well back into the rock to avoid the rain water gushing down from the valleys. The most prominent example for this type of protection is the Khazna Fir’aun. Other monuments are cut out of the rock; in there case, the exposed facades had to be protected by water drainage systems which had to be installed on top or behind them. Good examples for this category are ad Dayr or the so called „Palace Tomb“.
Fig. 13: Top of „Soldier Tomb“ before clearing (photo: S. G. Schmid)
The water management system of the „Soldier Tomb“ belongs to the second category. Remains of a rock-cut channel draining water towards NE to the area between the Wadi al-Farasa East and the Wadi al-Farasa West, where many huge cisterns are located, were partially visible before clearance in the area began (Fig. 13).
Fig. 14: Rock cut basins and water channel from drainage system on top of „Soldier Tomb“ (photo: S. G. Schmid)
The cleaning revealed the canalization for a length of about 10 m (Fig. 14). On top of the „Soldier Tomb“ there are two installations for collecting water. On the northern part there is a small basin that feeds the canalization and on the southern part another was connected to the first one. While the first basin is completely cut into the rock, the second one consisted of small walls built to collect water preventing it from running down the facade. The cut out rock to hold these walls are still visible. It would be easy to reconstruct them and to make the ancient water drainage system work once again for the protection of the facade.
Fig. 15: Roots of plants growing in water channel on fig. 14 (photo: S. G. Schmid)
Regular maintenance of these installations would be necessary because the strong roots of the different plants which grow there endanger the soft sandstone and the canalizations (Fig. 15).
