||WATER HARVESTING IN POOLS AND CISTERNS
||The restoration of ancient techniques for catching and holding water
Click the globe to see the technique on Google Map
Lalibela is one of the most remarkable hypogean monuments in the world. It is universally celebrated for its highly decorated monolithic churches hewn out of basaltic rock. The most imposing monuments date from twelfth and thirteenth centuries, when King Lalibela, from whom the city takes its name, called for it to be hewn out of the rock in the image of a Celestial Jerusalem. As it was hitherto unclear how such vast hypogean systems could be made in such a short period of time, religious tradition came to attribute the feat to divine intervention. In the framework of a joint UNESCO, UNCCD and WMF project, Ipogea undertook a comparative study of rock-hewn building types and an analysis of water catchment and drainage systems, and reconstructed the long-term history of the city of Lalibela from the remote troglodyte past through the hypogean period to the Axumite and the medieval, in which most building consisted of reworking earlier structures
Problems, causes and effects
The monuments of Lalibela are in danger because the work of draining, channeling and otherwise protecting them from water, has ceased over time. The churches exist together with their overall ecosystem; if the latter is not protected, they run the risk of vanishing forever.
The erosion of these monuments has been contrasted using traditional methods, first of all by identifying and cleaning an ancient trench that had been abandoned and blocked by tons ofebris. Restoration work therefore has not been limited to the twelfth- and thirteenth-century monuments on the UNESCO World Heritage List: the excavations aimed at restoring the old water system have also served to drain excess water and to turn it to irrigation. This water is collected in the trench and stored in an open cistern built in a spot where traces of old walls have been found. Here the present inhabitants of the village, which is intermixed with the ancient ruins, have returned to draw the water they need, as they had done centuries ago. This trench was cleaned by Ipogea under the UNESCO project because it was filled with debris and appeared to have no drainage capacity. Once the cleanup was completed, it became clear that the trench was inclined to the north, permitting the water to drain into the main waterway, called the River Joerdan. Today local people can fetch the water collected in the western trench. The UNESCO project yielded significant results. These actions should be extended to all the drainage trenches and tunnels
The monuments of Lalibela are just the visible part of a complex architectural and environmental system to which they are closely connected. The network of trenches and channels for conveying water, and the sunken courts where the churches of Lalibela are found, constitute a whole that, only if confronted in its totality, will enable one to respond to the factors that are causing its deterioration.