The Dahlak Cisterns
When you set foot on the Dahlak Islands, the first thing that strikes your mind is how people manage to survive there.
The Dahlak Islands are an archipelago or composed of many small islands. They are located around 50kms away from the east of Massawa. Dahlak Kebir is the largest island of the Red Sea. It is a coral reef island which is almost a plane area and barely possesses large geological features such as mountains, valleys, gorges…etc. Besides, there is a very little annual rainfall and throughout the year Dahlak has harsh tropical climate, as a result a limited number of species of shrubs and grass grow in this area. It is used as a pastureland for camels, goats and also to a few gazelles. Maybe, all this is the reason why they call it ‘Dahlak’. Based on preliminary information, the name ‘Dahlak’ is derived from ‘Dar Halak’ an Arabic word, meaning ‘The horrible Land ‘.
There is no doubt the name suits the island very well. However, when you further explore around, you simply notice various settlements, ruins, graves, cisterns and so many other traces of civilization. These traces belong to different periods of time in history, which extend from the ancient Adulite period until the recent historical sites such as Nakura. But one can only wonder as how such civilizations flourished throughout history despite the harsh and waterless environment. It was known that, almost all of the civilizations and traces of humankind were based alongside water resources such. So how can societies live in such environment for more than two thousand years? The answer lays on the view; some may suggest that trade was based on the geographical strategy and some say it was the tortoise shells and pearl fishing, which Dahlak is best known for. But the basic thing is the water preservation mechanisms which enables the people to survive and those are the cisterns.
The cisterns in the Dahlak Island are found in a great number and people throughout history depended on these cisterns for their prosperous civilizations. The locals are attributes to the tradition of construction of wells and cisterns, which once belonged to the Farsi or Persians. The Persians had control and influence in the southern part of the Red Sea coasts and Islands in different periods of time. Therefore, the historical accounts regarding the Farsi tradition still remain. According to the oral tradition of the locals, there were 365 cisterns in Dahlak, meant to provide water everyday throughout the whole year. In the 17th C. AD a Turkish traveler Evliya Celebi wrote about Dahlak and mentioned that there were 600 households each one of them having their own cisterns in the village. However, a century later the British James Bruce stated that he had seen 360 cisterns at the village. Later on in the second half of 20th C. Puglisi recorded 70 cisterns at the same village.
Today the ruined settlements and the surviving villages have minimally ten cisterns and wells around, and in many cases the number of cisterns exceeds the number of households. It is difficult to identify the number of cisterns, as many of them are buried with silt and almost covered by the vegetation, so it is not possible to estimate the total number of cisterns. Either way Dahlak was well known for the abundance of cisterns and availability of fresh water. According to historical accounts, Dahlak was the source of fresh water for coastal settlements such as Massawa until 1870’s and also for merchants and travelers of the Red Sea.
As the numbers of the cisterns differ from place to place, so does their structure and construction techniques. The most common are the wells that are carved in the compact rocky limestone or coral reefs of Dahlak with a cylindrical shape, with a diameter of 1 meter and depth of 4 – 20 meters. The depth varies upon the surface elevation, in which on the higher elevations it reaches to 20 meters and on the lower elevations below sea level. This depth allows the wells to reach the table water. During the rainy seasons, the wells are filled with rain water through flooding. The salty water retreats and fresh water occupies the space, as it’s denser than the fresh water.
However, during the dry seasons, the salty table water conquers the wells again. These kinds of wells are locally known as Sari and they are found abundantly everywhere in the current villages and ruined settlements. Though, they are functioning and serving the people, many of them are also either deposited or filled with silt or they are out of water. The water from these kinds of wells are too salty, except during the few rainy seasons. So the locals used it for their animals and for washing their house hold utensils.
Other kinds of water reservoirs are the cisterns, found in a great number in most of the current villages and ruined settlements of the Dahlak Island. These cisterns were usually constructed along the small rifts and channels of the Island for the purpose of being filled with rain water. The rainwater flows naturally from the area around, sometimes from canals carved in the rocks to facilitate the passage of the water.
Basically, there are three types of cisterns in regard to their construction techniques. The most common cisterns have a circle opening; most of them are enclosed by a ring shaped wall not more than 30 c.ms long, and usually with a diameter of 1m. The inner parts of the cisterns have a pot-like oval shape. Most of the time, it measures up to 8m in diameter and has a depth of 2 - 4ms. They are carved in a compact rocky limestone and some have a wall constructed with coral stones, which are heavily plastered with strong grey mortar inside in order to prevent leakage. In many cases, there are canals as long as 40 m, carved to make a passage to the cisterns. Such cisterns are also locally called Sari and they provide drinking water. Most of these cisterns are found in the village of Dahlak Kebir and they are still in use.
The second types of cisterns, are found in a few villages and ruined settlements, locally known as Sanda. These types of cisterns are located alongside the little gorges in order to get the flowing rain water. They have a square opening without any enclosure; in addition, they are carved through the rocky limestone, for a depth of 2 - 4m. They have a diameter of 1m and are plastered with grey mortar.
The third type are only found at the village of Dahlak Kebir, and they are very few in number. These cisterns are also the largest ones; they have a rectangular plan with an approximate width of 15 x 5m, and they have a depth not more than 4 meters. Some of them have pillars inside to support the ceiling above which is built by coral stones and tampered with locally made grey mortar. One of the well-known cisterns among these, is the Sultan cistern. It has a rectangular plan of 8m x 4m and has an arc designed ceiling. It is plastered very well with grey mortar and also has a 10m canal towards it. Locals believe that it was built by the sultanates and was used exclusively by the sultan’s household.
As mentioned above, the Dahlak cisterns are marvelous and reflect outstanding structures, which show how people can survive by harnessing their environment. They also have a great potential for being selected in the world heritage list, as they represent a master piece for human creative genius and exceptional testimony of different past civilizations in Dahlak and Eritrea.