Rainwater harvesting was used extensively in Petra, as it is the most archaic device that humans have used. In Petra this meant using the technology on the high places and on bare sandstone walls with many innovations. The Nabataeans used various types of cisterns that they carved out of the rock and waterproofed using chalk. These cisterns ranged from small pools on the highlands to catch runoff to rectangular shaped cisterns at the bottom of the natural drips. Small pools were carved out of the highland and evolved into bell-shaped cisterns. These large cisterns are similar to large rooms carved out of vertical walls into which complex canals and pipe networks flow (Laureano, 2001). What is so unique is that the Nabataeans used every slope and surface as a means to harvest rainfall and stored every water source from a few drops to the large floods. This is why Strabo, the 1st century geographer, described Petra as ornamented with fountains and basins (Laureano, 2001).
Khottara make use of traces of moisture and night condensation of fog and dew by harvesting the exudation of condensation (humidity) by dripping into tanks, cisterns, or channels that catch the water on the walls and conveys it to pools. These structures provide water all year round. On the other extreme, one cistern called
Fig. 1.19 Flood trap at Bir Huweimel (Petra). Flood water is diverted (A) and then cleaned by means of spiUways in consecutive basins (B) and fiUs up the large underground cistern (C). A staircase (D) leads to the cistern and water is drawn from the cistern through the well (E) (Laureano, 2001)
Bir Huweimel at the bottom of Ras as-Slimane, actually traps flood water using a large room (depth of 9 m) excavated in the riverbed. Flood water is diverted to water intakes and decanting basins as shown in Fig. 1.19, to fill the large cistern where the water is stored. A staircase is used to enter the cistern and water is drawn from the cistern through a well.
The Ain Masa spring, approximately 7.0 km east of Petra was one of the water supply sources, which is very hard containing a high percentage of dissolved lime causing deposits in the pipeline and channel. Water also entered the Siq water lines from the Reservoir Surraba, at a height of over a 1,000 m just outside of Petra. Two aqueducts were constructed from the reservoir; one toward the south fed pipes of the Siq and the other to the north to the Wadi Al-Mataha and then along the Wadi to Petra.
World History
