Newsletter and Technical Publications
of Alternative Technologies for Freshwater Augumentation
2.1.9 Use of Cisterns
Cisterns are an ancient method of water harvesting, dating back to the
early Roman empire. There are artificial reservoirs constructed by
excavating bedrock, such as limestone, to depths of between 3 and 7 metres
to provide water storage throughout the Roman world. While serving a
similar purpose, modern cisterns are usually built with cement blocks or
Cisterns collect water in the form of runoff from a rock-lined catchment
or other suitable, nonporous surface. There is commonly a settling basin
at the cistern entrance which serves to settle sediments borne by the
runoff. A screen is also provided to remove larger particulates.
Extent of Use
This technology is used in a number of north African countries, where it
is known by a variety of different names. These names are indicated in
brackets. The technology is used in Libya (where it is known as Fusqia
or Majen), Algeria (Sahrij), Egypt (Roman reservoir),
Tunisia (Fuskia pool), Morocco (Al Majel), and Sudan
(ground reservoir). Operations and Maintenance Routine maintenance is
necessary to reduce losses to leakage by repairing cracked walls. There is
also a need for the periodic removal of sediments which might choke the
Level of Involvement
This technology can be constructed, operated and maintained by
The cost of implementing this technology is reasonably low, as most of
the construction of the cisterns can be done by communities. However,
mechanization is increasingly used for the digging of the cistern, which
increases the cost.
Effectiveness of the Technology
The volume of water harvested depends on the amount of rainfall and the
size of cistern. Major losses of water generally occur in the catchment
area, through infiltration and evaporation, rather than from the cistern
itself, provided the cistern is maintained.
The technology is suitable for use in all regions of Africa and is
similar to rock catchment systems. In areas of high evaporation, the
cistern should be covered to minimize evaporative losses.
The use of cisterns to capture runoff has no known negative
environmental effects, and can provide water for a variety of
environmental purposes in dry areas.
This technology has the advantage of being a simple, low cost technology
which can increase the yield of water from rock catchment systems.
Use of this technology may require provision of an abstraction system to
draw the water from the cistern. Because of the likelihood of
contamination from surface sources, this technology is not ideal for use
as a potable water source.
This technology is culturally acceptable by the communities in which it
has been used.
UNESCO Regional Office for Science and Technology for the Arab States,
Arab Centre for Studies of Arid Zones and Dry Lands (ACSAD) 1986. Regional
Project on Rational Utilization and Conservation of Water Resources in the
Rural Areas of the Arab States with Emphasis on the Traditional Water
Systems, UNESCO Project ROSTAS/HYD/1/86.