Water Management in Petra, Greece: An Overview of Nabataean Hydraulics

Irrigation at Petra

Most of Petra lies in an area of sandy stones in which there are many valleys, such as Wadi As Surayi and Wadi Al-Matabha. This fact made the area around Petra dangerous in rainy seasons because of floods, especially the low areas, because of the many valleys and the high speed of the water that flows on the sandy stones. The Nabataeans were forced to build dams in many of these valleys for two major purposes. The first purpose was to make use of the rainwater for drinking and irrigation.

The second purpose was to protect the various buildings and stations that lay in the low areas at times of floods and drifts. Petra is almost empty of springs and water, except the spring of the Wadi Siyyagh that lies in the western side of the city. It is a spring with a little water that lies in a low area of the city. There are some other areas that include a little water, such as the Qattar Al-Deir area, in addition to a small spring in the valley of Abu-Aliqah, but its water is salty and is not suitable for drinking. These sources are not of great importance in supplying Petra with water [4, 5].

The oldest reliable archaeological dating evidence for rainwater harvesting agricultural practices in the Negev has been found to date to Iron Age II 1000-539 BC [7]. However, it was only in the Nabataean and Roman periods that rainwater harvesting agriculture reached its peak in terms of development and acreage covered around 4000 hectares out of 200 000 hectares available [8]. In north Jordan, farmers built similar systems of runoff farming using cleared catchments and ‘cross wadi walls’ [4, 9].

The hinterlands surrounding Petra and other Nabataean settlements throughout the desert region show signs that the Nabataeans practised agriculture on a large scale to feed their growing population. They devised elaborate and intricate systems for water catchments and irrigation as a means of extending the boundaries of agriculture farther and farther into the desert [4, 10, 11, 12]. The effects of this massive terracing system on the landscape were so great that, centuries later, Nelson Glueck identified many settlements along Wadi Araba and in the Negev desert as “garden cities”, whose extensive field and hydraulic systems demonstrate the Nabataean efforts towards “the fructification of deserts” [12]. The only written evidence for land organization in the plateau region before the Byzantine periods comes from a short Nabataean dedication stone of eight BC from the large cult centre at Khirbet at-Tannur, dedicated by the ‘curator’ of the source of Wadi La’aban. Villeneuve suggests this may hint that there was a local organisation for the control of spring water and irrigation within the valley [13]. However, the curator may have been the keeper of the spring water.

Because the region’s limited rainfall comes only in the winter, the emphasis of the Nabataean system is rain catchments and storage for use through the long arid summer months. When the rainfall does come, it is usually in the form of sudden outbursts and the hard soil and impermeable rock are unable to absorb the water quickly enough. Instead, it flows rapidly across the surface and into the dry wadis where flash floods often develop, carrying topsoil along with rocks and debris, which are deposited in the wadis and catchment basins. In an effort to conserve precious resources, the Nabataeans built walls and terraces along entire wadi systems in order to trap silt and water on the slopes and spread it out for wider use [3, 4, 14].

The main wadis were converted into u-shaped terraces to divert the water and silt into the side plots. Upstream conduits and collector walls led the water to downstream plots that might otherwise have been missed when the floodwaters rushed by Evenari and Koller [11]. Dams were constructed across wadis to slow the water and reduce its force and to store it for subsequent use [15].

This system allowed for the irrigation and cultivation of large field crops (mainly grain), as well as orchards and vegetable gardens, enough to fulfil the demands of a growing population [4, 11, 12]. Furthermore, Strabo states that the Nabataeans have mastered the arts of irrigation and enjoy rich harvests of cereal and fruits from across the kingdom (Strabo 16.4.21). A good indication of the farming practices of the Byzantine period of the sixth century AD has come to light recently with the unearthing of the carbonised papyri from the storeroom of a Petra church [16].

According to papyri found at Nessana in the Negev, the Nabataean water system permitted the successful cultivation of barley, wheat, legumes, grapes, figs and dates [11]. Many of the ancient channels and terraces are still extant and some continue in use by the local population. Also, they are still using the water from Muse spring: everyone has two hours to irrigate his field. They manage this between them, depending on the size of the land, sometimes allowing more then two hours.

A good indication of the farming practices of the Byzantine period of the sixth century AD has come to light recently with the unearthing of the carbonised papyri from the storeroom of a Petra church [4, 16]. Although not fully published yet, these papyri, most of which are in the form of legal contracts, have provided a wealth of information concerning the administrative organisation and agricultural methods of the plateau region. The most important evidence in this regard has come from roll number ten, which is concerned with the division of property and land between three brothers [16]. Mention is made in these papyri of sown lands for wheat; vineyards; and houses with adjoining orchards which would have been irrigated by hand and which are common in Jordan today. A further roll fragment mentions a “regular orchard” which has been interpreted as referring to an irrigated orchard, as seems to be the case with similar papyri from Nessana in the Negev [4, 16]. It is also interesting to note that the land divided up in roll ten was scattered in plots across a relatively large geographical area, and that the individual fields were small in size, from around 2.6 acres up to an occasional maximum of around sixteen acres. As Koenen suggests, this reflects well-known methods of risk management where the availability of water could fluctuate wildly from year to year at different location within a very localised area [16]. Documents in the Nabataean language from the Wadi Habra west of the Dead Sea, give us an idea how the distribution the water between of worker farmers in Nabataean period was arranged.

Storage of water

The Nabataeans displayed the greatest intelligence in their selection of location through several different geographical and geological aspects.

Once the demands of field irrigation were met, surplus water was diverted into cisterns and reservoirs for storage and domestic use. Water collected in winter had to be stored for use through the dry season for at least 12 to 24 months for irrigation and for drinking. It is estimated that a minimum of 10-20 litres per day per inhabitant was required for drinking and washing [4, 17]. Fall-off points and natural catchment basins were enlarged. Channels were cut into the side of every hill and rocky outcrop to collect water and conduct it to established storage sites. Small reservoirs were established along the wadis and shielded from the sun by rocky outcrops and trees to slow evaporation [11, 18]. However, in order to fulfil the demands of large populations in a desert environment, large underground cisterns were a necessity. Some cisterns were enlarged caverns with pillars to support the roof; others were entirely man-made, dug into the limestone strata which are naturally water bearing, and lined with plaster for additional waterproofing. Nabataean cisterns were typically roofed over with long stone slabs supported by transverse arches to prevent evaporation and pollution [4, 12, 19, 20]. The overall dimensions of the cisterns were limited by the arch span. A study of Nabataean roofed cisterns in Jordan and southern Palestine shows that their width was limited to 6 to 7 metres, and their depth was 5 to 6 metres. This led to an elongated, rectangular design for public cisterns in order to obtain the desired capacity [20].

Nabataean roofed cisterns are found at virtually every known Nabataean site: Petra [21, 22]; Humayma [19], Ramm [23], Ain El-Khalde [24]; Jabel Ratama [24]; Mahmal [25]; Qasr Wadi Es-Siq [26].

This roofing design was borrowed from Hellenistic architecture and continued Sedimentation in use throughout the Byzantine and early Islamic periods [20]. Basins placed at the narrow entrances to the cisterns helped to purify the water of silt and other pollutants. A small opening in the roof allowed water to be drawn by means of buckets [11, 18]. Writing about the Nabataeans in the late 4th century BC described subterranean reservoirs with small opening and concrete lining.

Larger open-air reservoirs were less practical because they were more subject to loss by evaporation-between 3 and 4 metres per year- than a closed cistern or covered reservoir. In addition, open reservoirs require constant upkeep due to the introduction of pollutants such as insects, animal waste, plant debris and the growth of algae under the hot sun. As a result, the occurrence of larger reservoirs is generally restricted to the outskirts of settlements where they were probably used as watering holes for livestock and passing caravans, or as a resource for filling nearby domestic cisterns when necessary [20, 27]. Glueck describes large rectangular reservoirs (Birkeh) at et-Telah (Toloha) in Wadi Araba [12] and at Umm al-Jimal [4, 28] that date to the Nabataean period. At Humayma, a reservoir measuring 27.6 x 17 x 1.75 is located at the northern edge of the city [20, 27]. The use of seven alternating courses of headers and stretchers in the wall construction and diagonal dressing on the ashlars and stretchers in the wall construction is noted. The second reservoir at Humayma cistern 1, dates to the Roman period [27].

The walls are topped with stone paving to form a walkway around the perimeter. The interior of the reservoir is lined with hard, sandy stucco. Water was fed by an aqueduct that entered the reservoir through an opening at the centre of the northern wall [27]. Nearby, a large stone was found with a basin and several covered diverting channels leading into it [27]. A similar basin found in situ at Sobata functioned as castellum-diverted water to another smaller cistern once the main reservoir had reached its capacity [27].

At Petra, the Nabataeans, conquest of the desert went well beyond the practical needs of crop irrigation and drinking water. As with all of their settlements, the Nabataeans constructed extensive water collection and supply systems for their capital city. As Hammond observed: “In a land of high cliffs and deep fissures, as well as desert wastes, the stonecutter became the engineer’s ally, and the abilities formerly devoted to tomb facades and sculpture were diverted to the production of runnels, diversion channels, cisterns and water control system” [15].

In his description of Petra, Strabo stated that, there are abundant springs of water for domestic purposes and for watering gardens [29]. An extensive system of channels and aqueducts carried water from spring and catchment areas to numerous cisterns and public works throughout the city [29]. At many points along the way, arches were constructed to carry the aqueducts across deep crevices and uneven terrain. The use of arches and the installation of the pressure pipe allowed the Nabataeans much freedom in their design of hydraulic installations and ultimately enabled them to virtually disregard the topography [30].

The main water source for Petra is Ain Musa (Spring of Moses), which tradition honours as the spring that burst forth from the rock when Moses struck it with a staff. Ain Musa is located in the eastern hills approximately 7 kilometres from the City Centre. Downstream from Ain Musa, above the entrance to the Siq, a large freestanding reservoir collected the spring water for controlled distribution into the city and its environs. One route was via a channel cut into the southern wall of the Siq and covered with stone slabs. Later, a deep groove was carved along the Siq’s northern wall and installed with interlocking high-pressure ceramic water pipes [4, 15]. The pottery pipes are later than the Siq paving Hammond [15] dates them to the reign of Aretas IV [22].

The narrow Siq, however, proved to be a dangerous place during the rainy season. Water flowed into it through nineteen faults and inlets resulting in dangerous flash floods carrying earth and debris and anything else in their path along with them. The Nabataeans designed an intricate hydraulic system in order to control the life- threatening floodwaters.

The paved road through the Siq was laid at a gradual decline to lessen the water velocity. Dams were erected across smaller side wadis along the Siq to contain the water and create small reservoirs for use in the dry season. The construction of a diversion dam and a tunnel, 40 metres long, at the entrance to the Siq diverted the bulk of the water around the base of Jabal al-Khubtha where it emptied into Wadi al-Matabha [31]. From there, the water headed downstream to converge with Wadi Musa, where additional diversion channels and erosion control walls kept the flow in check as it passed through the centre of the city [4, 15].

Two other springs, in addition to Ain Musa, are known to have served Petra in antiquity. Ain Braq, located in the eastern hills a few kilometres south of Wadi Musa, was of secondary importance, mainly serving the agricultural lands and residences south of the city centre. The spring in Wadi es-Siyagh probably never played a major role in supplying Petra’s civic needs, due to its location west of the city centre at a significantly lower elevation. When the demands of the thriving city outgrew the output of the three local springs, an aqueduct was constructed that carried water from Dibdibeh-several kilometres northeast of Petra, across a bridge spanning a deep ravine and into the northern section of Petra. A group of more than thirty French tourists were killed during a visit to Petra in the 1963 when a wall of water crashed through the Siq following a rainstorm. Since then, the restoration and reconstruction of the ancient Nabataean water control system has prevented similar tragic events [4, 5, 10, 15, 30].

“Just as their resources were smaller, Nabataean applications of running water were fewer, and the physical arrangements for distribution correspondingly less elaborate than those for a Roman metropolis. Instead of being divided up into pressurised pipelines serving public fountains, public baths, and private homes - the water splashed quietly into public reservoirs to which access was arranged by Nabataean deity [32]. The overflow from the primary storage tanks probably was conducted into private cisterns and small agricultural plots in accordance with similar arrangements” [20].

The Siq

The narrow Siq, was installed with a water channel and ceramic pipeline along its south and north faces, respectively. Their primary purpose was to help control floodwaters and to provide an easy means of transporting unpolluted water into the city. In addition, it is likely that the presence of these hydraulic features served a secondary, symbolic role. The sound of the water that flowed, unseen, inside the covered channel and pipeline, would surely have been audible to passers by, as a continuous murmur reverberating off the towering walls of the narrow Siq [4].

Many religious symbols are found in the Siq, thus, there is a close association between them and the waters that flow through it. At the entrance are three-square towers or “god blocks” carved from the sandstone, and more than 60 god idols, or stelae, are carved upon the walls at various points along this long, winding passage [33, 34, 35]. Most of the representations of Nabataean deities are aniconic and thus presented as simple carved blocks of stone or stelae. Anthropomorphic representations of Nabataean gods began to appear in the 1st century BC as a result of Hellenistic influence but are few in number [4, 35, 36, 37].

Particularly notable is a relief sculpture discovered during the recent excavations in the Siq. Two pairs of camels (1½ times life-size), each led by a male guide, are carved into the rock on the southern wall of the Siq. Only the lower half of the guide is preserved showing his draped garments, sandals and a staff. Of the camels, only the feet and lower portions of the legs are well preserved. Although their bodies are badly eroded, one can make out their general outline in the rock face above the water channel [4].

This relief was carved either before, or at the same time as, the water channel that is credited with the existence and success of the city; the specifics of its design suggest a less functional meaning. First of all, these camels do not appear to be carrying burdens and, thus, are not represented in their role as pack animals. Secondly, the arrangement of the scene, with each pair of camels and their guides facing each other, is more reminiscent of ritual scenes where a venerated subject, god, icon, king or altar stands at the centre of a symmetrical arrangement of worshippers or participants. It has been suggested that an altar once stood between the two sets of camels [4, 5, 38].

A similar scene, also badly weathered, is depicted in a relief near the ed-Deir monument, in which a carved niche is flanked by two guides, each leading a single camel. Nearby are channels and a small collecting pool carved into the bedrock. In these scenes the camels appear to be part of a ritual procession, possibly leading to their own sacrifice [4, 38].

Fountains

The veneration of water, especially springs and rivers, is one of the most ancient and universal forms of worship. It is a universal phenomenon that persists through the time and space due to role further as a basic human need. Because of its crucial role as a life giving resource for the desert nomads, it is not surprising that the Nabataeans perceived water as sacred and that many examples of ornamental water display at Petra held religious significance. Numerous religious icons, inscriptions and sanctuaries are found in association with springs, catchment pools and channels throughout the city and its environs [4, 5, 10, 33, 34, 35, 39, 40, 41].

One Nabataean deity in particular may be associated with springs and water. This is the goddess Al-‘Uzza, consort to the patron deity Dushares. Al-‘Uzza is most commonly represented as a rectangular stele on which two schematic eyes and a nose are carved [35]. In inscriptions, Al-‘Uzza is associated with the Greek fertility goddess, Aphrodite, as well as the Syrian fertility goddess, Atargatis [35]. The decoration on a gold earring found in a Nabataean grave at Mampsis (Mamshit) in the Negev, combines the features of “eye idol” with an image of a standing female nude that is more commonly associated with Aphrodite Anadyomene (“rising from the sea”) in Hellenistic Roman iconography [35].

Atargatis is the goddess of fertility and the life-giving forces of earth and water. In the Nabataean temple at Khirbet et-Tannur, anthropomorphic representations of Atargatis show her against a backdrop of abundant flowers and fruits wearing a headdress of dolphins or fish [4,28,]. Atargatis is also represented at Khirbet et-Tannur in association with lions, a common attribute for the chief female details of Near Eastern and Classical religions [28, 42].

The use of carved lions in the architectural details of the Temple of the Winged Lions at Petra, and the discovery of an especially well carved “eye idol” inside that temple, allows this structure to be identified with the veneration of Atargatis/Al-‘Uzza [35]. However, there is no known water source or water installation in the vicinity of this temple.

Direct associations between water and the veneration of Atargatis /’Uzza are found elsewhere in Petra. A stele carved into the rock face above the spring in Wadi es- Siyagh is accompanied by a dedicatory inscription to Al- ‘Uzza [43]. En route to the “High Place of Sacrifice”, the site of ritual sacrifice on the rocky summit of Jabal Attuf, a votive fountain, in the form of a lion (4.5 metre high), with its body in profile and its head frontal, is carved in relief on the mountainside. Water was transported down from the summit via a deeply carved channel and poured out through an opening in the lion’s mouth into a basin below. Other representations of lions in association with water are found at Qasr Rabbah and Khirbet et-Tannur in the form of lion-headed waterspouts [4, 28].

During the Roman period, the Nymphaeum, a monumental public fountain, was constructed near the confluence of Wadi Muse and Wadi al-Matabha, at the eastern end of the Colonnaded Street. Only the foundations of the Nymphaeum’s semi-circular plan remain, so the details of its appearance are lost to us [22, 44]. Based on examples at other sites in the Roman East, the Petra Nymphaeum can be reconstructed in the shape of an exedra, its face decorated with carvings of water nymphs to whom the monument was dedicated [4, 42, 45].

Across the front of the Nymphaeum is a large basin that would have been filled by water flowing from at least one fountain built into the façade. The Nymphaeum was a standard feature in all Graeco-Roman cites that was adopted into the Hellenised Near East. The origins of the Nymphaeum can be traced to religious sanctuaries located near natural springs or streams; an offering was made in honour of the water nymphs that were believed to inhabit these secluded watering holes. Although the sacred significance of the Nymphaeum was somewhat lost in its Roman transformation into a public monument, its role as a symbol of the water upon the Nymphaeum of Petra provided passersby with a convenient resting spot and gathering place, where one could refresh oneself with a drink and cool spray from the fountains. As a place of congregation for citizens and non-residents alike, the Nymphaeum stood as a symbol of the volume of water entering Petra and, thus, held an important role as a status marker for the city. The so-called “South Nymphaeum” has not been excavated and may not be a Nymphaeum at all. Its plan is that of a small temple or shrine [42].

Water Falls

It is to be expected that many waterfalls, both natural and artificial, could be witnessed throughout the Petra region during the rainy season as running water navigated the rugged landscape. In many cases, the Nabataeans constructed arches across deep gorges to act as bridges for aqueducts and, thus, maintained the flow at a desirable gradient. Elsewhere, water was channelled to the cliff’s edge, where it dropped off into basins or catchment pools. Such waterfalls would have made a lovely sight but were unremarkable as natural features in any mountainous landscape. One waterfall at Petra, however, falls into an entirely different category. Carved into the sandstone cliffs adjacent to the Palace Tomb is a monumental niche standing approximately 20 metres high. Water was channelled around the northern edge of Jabal al-Khubtha to the top of this niche and cascaded over the edge to from a magnificent waterfall. At the base of the Waterfall is a series of terraced basins and a cistern [4, 46].

This man-made waterfall is remarkable not only for its size, but for its negative impact on the Nabataeans’ efforts towards water conservation. Although splendid to behold, the amount of evaporation off water of such magnitude was unnecessarily wasteful of the city’s most precious resource. Therefore, the creation of the waterfall, a feature of purely ornamental value, must have held enough significance to its creator and/ or the inhabitants of the city to justify its existence.

Another artificial waterfall is documented in the theatre at Wadi Sabra, a suburb located approximately 7 kilometres south of Petra. An investigation of Sabra’s catch water regulation system provided information about its hydraulic installations. According to Lindner, the theatre functions as the terminus for the runoff from the mountains surrounding Wadi Sabra. A dam constructed on the slopes above the theatre formed a reservoir with a holding capacity of 370 cubic metres of water. A small outlet at the base of the dam functioned as a drain emptying water into the theatre in the same manner as a fountain spills into a basin [47, 48]. This cascade of water out of the mountains and into the theatre is an overt example of water display. The ultimate destination and use of the water after it entered the theatre is not known, since excavations have not yet been undertaken within the theatre proper.

Early explorers speculated that the orchestra of the Wadi Sabra theatre functioned as a large water basin used to re-enact maritime battles, similar to the Roman naumachiae [4, 49, 50].

Water Management at Petra

The considerable role of water in the design and character of cities throughout the classical world is summarised in the following quote from a recent study of water supply and water technology in the Roman world:

“Water was everywhere in cities across the Graeco- Roman world. A metaphor for Life itself, it gave an underlying structure to the ancient city.It shaped urban topography and even local history. Water was hidden in deep wells and cisterns and gushed unseen through the conduits and armatures of aqueducts, to be distributed by the castellum aquae or to be used for irrigation outside the city. It bubbled openly in nymphaea, public fountains, baths and the labyrinth sewer networks that served them. Invisibly and visibly it lent form” [51].

The function of water in these cities was something much greater than providing drink to the inhabitants and nourishment to plants. In the public realm, waterworks, such as fountains and baths, formed the backdrop for communal activities. In Public Square, at the entrances to the theatres, assembly halls and religious sanctuaries and at major intersections of the streets, the presence of water increased the amenity of the space [4, 52].

In addition, the attention lavished on such public installations would remind the citizens and foreign visitors alike of the quality and generosity of the local leaders. The same is true of the waterworks at Petra. All of the examples of water display at Petra previously listed, with the exception of the Nymphaeum, date to the Nabataean period (pre-annexation) and, therefore, cannot be attributed merely to the Romans, whose passion for spectacular waterworks is well documented [2, 53].

Despite the great efforts in the area of water display by the Romans, Vitruvius writes surprisingly little regarding the incorporation of water into architecture for aesthetic purposes. His chapter on water is focused on the very practical methods of locating water sources, testing it for quality, transporting and storing it [32].

Due to the generous supply from the Tiber and the luxuries of their waterworks, no villa was complete without is baths, fountains, pools, channels and fishponds [54, 55, 56, 57]. At Hadrian’s Villa at Tivoli, arguably the most famous and extravagant of all Roman villas, the single most unifying element is water [58, 59]. The exhibition of water at Petra belongs to a much larger phenomenon of human psychology, in which water’s aesthetic and symbolic values are used to provoke emotions and make statements regarding wealth, status and power. In addition to its aesthetic appeal, water has a way of exciting human emotions. Water is simultaneously the most docile and the most powerful of visible elements, and it is these two qualities that form the basis of the art of water display. “One stimulates the mind the other the eye” [60].

Due to its cleansing qualities, water is almost universally attributed with the value of purity. Throughout the near eastern and classical worlds, religious sanctuaries were fitted with pools and basins of water that permit both priests and worshippers to attend to their religious duties in a state of purity. Most notable, perhaps, are the sacred lakes and pools of the ancient Egyptian temple complexes known, through their depiction in wall paintings [4, 61, 62, 63].

Baths

At Petra, south of the Temenos Gate, the bath is located; it is dated to the first century BC. The bath consists of a circular room about 5.12m in diameter adjoining another square one. The structure is at underground level. The circular room has eight half columns with an Attic base. The roof is of a dome shape and was built of stone slabs with a circular window at the top. Remains of red stucco and coloured marble were found in the rubble. Connected to the wall of the circular room is a large staircase with stucco of red and yellow paint [22].

At Khirbet Edh-Dherih was discovered a unique area that consists of two rooms No16 and 17, which formalise the bath. The caldarium No17 was tiled and warmed by a hypocaust system and consisted of upper and lower parts, the latter is the cauldron that is supplying the upper one with a high temperature to get boiled water. The other room, No 16, is receiving the water vapour to be the Sauna room. The fuel’s storage room No 3 was approached by a passage located in the southern part of the building and had a direct link with the cauldron. What distinguishes the bath of Dharih that it is only one in the Nabataean sites that was discovered except Petra [64, 65].