THERE WAS LITTLE DOUBT THAT the underground water system of cisterns and conduits was huge and extremely complex and sophisticated but such installations were common to all ancient civilisations.
The technology for the retention, transportation and supply of fresh water was born at the dawn of ancient civilisation, necessary for agricultural irrigation or for towns and cities not built on the banks of lakes or rivers, or built for reasons of defence on hills and high places.
Ancient civilizations developed the materials necessary for water transportation and distribution systems. Such as waterproof coatings and joints of cement and mortar, terracotta tiles, pottery, ceramics, copper, bronze and lead.
Catchment techniques collected water springs, rainwater ground drawn from wells carried by aqueducts, canals, conduits and pipes flowing by gravitation along natural slopes. Most of these techniques were employed in the surrounding area of Jerusalem.
Aqueducts consisted of channels cut into the rock generally covered with cemented stones to protect the water clean and prevent them from being blocked by falling material. When there were hills on the path aqueduct tunnels were hewed into the rock. To facilitate the work and wielding of hand tools these tunnels were generally built with the height of a man. This has often resulted in archaeological observations that supposed these water tunnels were secret passages and in fact many did also serve as such though their primary use was to carry water.
When there were low valleys be crossed or permeable ground, earthen levees or dykes were built in which the water flowed over U shaped rock sections set end to end and sealed with different kinds of cement joints, the U sections were covered with slabs to protect the canal.
In the case of deep valleys or ravines bridges were constructed on which watertight channels was built. Such aqueducts were relatively vulnerable. This was the case for Jerusalem where the Etam Aqueduct crossed the Tyropoeon Valley inside of the city walls passing over the so called Wilson Arch to reach the underground cisterns beneath the Haram. Siphons were to cross certain small valleys or crests both upstream and downstream of Solomon’s Pools.
The storage of water in antiquity was in non-porous rock in ponds, reservoirs or cisterns hewed into the rock. These storage systems received water from springs or rainwater. Cisterns were cut into the rock enclosed by the rock itself or covered by stone slabs cemented into place.
The cisterns of the underground system in Jerusalem were disposed in cascade within the bedrock interconnected by conduits to form a single hydraulic system.
Etam was mentioned by Josephus Flavius when he described splendour of the royal court during the reign of the legendary King Solomon, and in doing so Josephus gave a certain legitimacy to the myth by his bucolic description of Solomon riding high on his chariot in the midst of his cavalry, dressed in a white garment, at a pleasant place called Etam, with fine gardens, abounding in streams.
The problem was de Lussac took the Bible stories of Solomon and Ezechias for historical fact using them to back his theories as to the use of the cisterns and by extrapolation fix the site of the Temple citing chapter and verse as proof.
From the archaeological view point there is a fundamental difference between the system of the so called Etam aqueducts and the underground systems of the Haram. Both of these systems had received constant improvements over the centuries up until the destruction of the third Temple of Herod.
Cisterns and conduits had been continuously added to the underground system by successive generations without the initial system of cisterns being radically modified. Therefore the different archaeological strata and installations situated in the bedrock have been preserved and could be identifiable by their time of construction.
On the other hand substantial transformations had been carried out on the Etam Aqueduct system over the centuries, designed to improve the supply of water to Jerusalem. Therefore, from the archaeological point of view the vestiges of the past were removed for ever. Thus the only remaining evidence was the paths taken of the aqueducts that ensure the downhill flow of water to Jerusalem.
Certain of these aqueducts had the mark L.X.F. of the 10th Fretensis Legion that was stationed in Jerusalem after the destruction of the Temple.
The most ancient aqueduct was extremely sinuous with twists and turns, and hair pin bends, using a very shallow slope, to take advantage of the small difference in elevation reservoirs and the cisterns in Jerusalem. The path was then modified and was relatively rectilinear, doubtlessly inspired by Roman aqueduct technology after the first century BC and especially the influence of Roman civilisation on the work of Herod, the protégé of Mark Anthony and then Augustus, and friend of Marcus Vipsanius Agrippa the son-in-law of the Emperor, who was very knowledgeable about Roman technology.
The three reservoirs could contain approximately 160 million litres of water. The upper reservoir measured approximately 120 long with an average width of 70 metres with a sloping floor having a depth of 9 to 11 metres. The intermediary reservoir measured approximately 150 metres long with an average width of 70 metres with a sloping floor having a depth of 10 to 12 metres deep. The lower reservoir measured approximately 180 metres long with an average of 70 metres wide with a sloping floor having a depth of 10 to 16 metres.
The difference in elevation between Solomon’s Pools, 780 metres above sea level and the point of entry of the aqueduct into the Haram underground 730 metres above sea level was therefore 50 metres and the distance as the crow flies 12 kilometres, but for the older more meandering aqueduct path this would have been about 24 kilometres following the contours of the natural topography and maintaining the a slope so that there would always by an inclination in the direction of Jerusalem, this was in the order of 0.21%.
On reaching Jerusalem the aqueduct had to cross the Tyropean Valley running alongside the western ramparts of the Haram to penetrate into the Haram’s underground. The vestiges of a bridge situated to the north of the Wailing Wall and approximately midway between the Dome of the Rock and the Al-Aqsa Mosque, called Wilson’s Arch, after the British officer of the Ordnance Survey, was no doubt built to carry the aqueduct and entered the Haram at an elevation of 727-729 metres above sea level, with the surface of the Haram at this point being approximately 738 metres above sea level.