Ancient Cisterns in the Negev
Cisterns from past generations
People of former generations dug cisterns in soft rock that was relatively impermeable to water. The material they dug out was disposed of near the cistern. Hence, the piles of light colored material indicate, to those who read the landscape language, that there is a good chance of finding water here. The ancients often collected water in the cisterns by converting natural water courses (wadis) into channels, or by constructing channels along hill slopes.Even today, such constructions, if identified, may assist the wanderer in the desert in his search for precious water.
A typical cistern of this type is shown in Fig. 4.5.1. I myself first saw it on an excursion when I showed my partners the difference between the appearance of [Pistacia atalantica] trees growing in the main channel of Nahal Elot, and the tree growing on a slope of the catchment area of Nahal Elot. Even before using the field binoculars their habitats could be differentiated. The P. atalantica trees grow in the channel of a large watercourse through which flow large quantities of flood water, whereas the tree in Figs. 4.5.1b and 4.5.2 grows accompanied by shrubs of Artemisia sieberi and Noaea mucronata, which testify to a poor local moisture regime. There are habitats where [Pistacia atalantica] trees grow close to mountain tops, but this occurs on rocky slopes. When using the binoculars the pile of light-colored soil (Fig. 4.5.1a) and the pair of channels feeding the cisterns (Fig. 4.5.1c) could be seen as well.
In order to achieve good storage of water and avoid water loss by percolation, the cistern was dug in a clay-rich marl. The efficiency of the water system is clearly demonstrated by the water accumulated there at present. Some fifty years ago, I accompanied Dr. Y. Aharoni during his study of a cistern, 7 km north of Mizpe Ramon, known today as “The Officers Cistern”. Dr. Aharoni stated that the cistern belonged to an Israelite fort from ca. 3000 years ago, and wrote a note. The cistern in Fig. 4.5.1 resembles the Officers Cistern (Fig. 1.5.6). Many years ago, a Tamarix nilotica germinated on the floor of cistern (Fig. 4.5.2), established itself and developed into a tree that withstands prolonged inundation as a result of the accumulation of water in the cistern. The tree sprouts and blooms every year in the spring time, indicating the presence of the cistern from afar. Fig. 4.5.3 shows a similar circular cistern with oblique stone protection walls. Being one of the cisterns reconstructed by the Nature Reserves Authority, the water accumulation and storage is efficient, especially in rainy years.
The cistern of Mt. Nafkha (Figs. 4.5.4 and 4.5.5) is one of the largest and most amazing cisterns in the Negev Highlands. Like the circular cisterns it was dug in a layer of soft marl, recognizable from afar by its light color (Fig. 4.5.4) amidst the brown limestone layers. The ancients drained a large catchment area by using a system of channels, the accumulative length of which reaches ca. 2.5 km. Anyone driving from Avdat to Mizpe Ramon can see the prominent channel and large cistern (Fig. 4.5.5) when looking westward from the asphalt road. A short walk on the slopes of the hill enables the visitor to observe the large water-harvesting system when walking along the channel (Fig. 4.5.5a) towards the cistern (Fig. 4.5.5b). The ancients dug a channel (Fig. 4.5.6) and protected it from erosion and destruction by means of an inclined wall of 3-4 courses of stones. Although the channels are broken in several places, water still flows towards the cistern, whose size and structure is beyond belief when first seen (Fig. 4.5.7). The walls, the steps leading to the water, and the supporting column that held the ceiling, are amazing. With time, the ceiling fell down, together with the thick layer of rock above it. The people who survived this disaster cleaned the cistern and enlarged the pile of stones and soil that is visible from afar. Another prominent event that took place there is the germination of Tamarix nilotica on the wet floor of cistern. Some 50 years ago, when I first came to the cistern, I walked around it and found a chert tool (Fig. 4.5.8) that linked me personally to the builders of the cistern. I found the two chert components (Fig. 4.5.8 on the right) a few meters from each other. The stones fit together and one can reconstruct a working tool by attaching the left part of Fig. 4.5.8 to a handle with a Thymelaea hirsuta rope. The handle can be made from branches of Pistacia atlantica which grow in the wadis around Mt. Nafkha. There are also plenty of Thymelaea hirsuta shrubs in the area.
Cisterns dug in the northern Negev, in an area having a mean annual rainfall of over 200 mm, resemble cisterns of the Negev Highlands with regard to the soil-rock pile near the cistern (Figs. 4.5.9-4.5.11). It is hard to see channels in this area, and it seems that the soil pile was used as an important part of the catchment area. In the lower part of Fig. 4.5.12, the entrance to the cistern may be seen, and the loess soil covering the chalk rock.