The photo is sourced from instituteforpublicart.org
The tower looks like a bamboo jar covered by a mesh made of nylon and polypropylene. The tissues of the mesh warm up under the hot sun in the daytime and quickly cool down when the dusk sets in, while the air remains warm. This creates a dew point – the air temperature, at which the air becomes saturated with water vapour that starts condensing into water. The liquid forming on the mesh trickles down under the action of gravity into a reservoir that is placed at the base of the structure and is protected from sun rays by an opaque canopy to prevent water from evaporating.
A tower can generate up to 100 litres of water per day, which is double the specific water consumption per capita in African countries (about 50 litres per day). No electricity is required for a tower to operate. The assembling of one tower can be completed in a day by a group of four to six people, after which the tower can be serviced with simple hand tools. Inexpensiveness is an advantage: a tower can cost $500 to $1,000 depending on its scale and structure, which can be modified to prolong the process of dew point formation.
These towers are already being used in Ethiopia, Cameroon and some other East African countries where the Warka Water project is being implemented. The project takes its name from the warka tree, which has a bulky trunk with sprawling branches whose ends come together in the shape of an overturned cup with a diameter of up to 50 metres. The trees, which can grow 50 metres high, are native to East Africa and have long been considered sacred by the region’s ethnic groups.
