One of the interesting pilot projects INBAR embarked upon in 2012 was to test if bamboo and rattan could be used to construct rainwater catchment tanks for local communities in Ethiopia and Nepal. The hypothesis was that bamboo is readily available and it is relatively cheap. Moreover, skills could be transferred to local entrepreneurs so that the tanks could be constructed without the need for external help, thus keeping the cost down.
When I lived and worked in Botswana in the seventies, we looked at rainwater catchment as the solution for providing cheap a supply of fresh water for domestic use in a country with very low rainfall and a dwindling underground water reservoir. I was working with an advisor to the International Rainwater Catchment Systems Association (IRCSA) which is promoting and advancing rainwater catchment systems technology. (http://www.eng.warwick.ac.uk/ircsa/) We facilitated the construction of a set of rainwater tanks at a medical facility in the village of Nata, and found that the few rainstorms that occur were sufficient to fill the tank and provide an additional source of water for washing, watering a vegetable garden and other uses. It even functioned as an emergency back-up to the council water supply.
I therefore liked the concept of the Ethiopia/Nepal project, and was very interested to hear the outcome. I had the opportunity to learn more, when I talked last week with one of the INBAR staff who was actively involved in the activity. The project constructed a 5,000 litre tank from flattened, treated bamboo strips, which were then plastered with concrete. A base was constructed to prevent leakage, and a domed roof was installed to keep the supply safe from pollution. The result was a cheap reservoir with a cost of USD 4-8 per litre. This compares very favourable with a plastic water tank which costs roughly USD 12 per litre while a concrete tank costs about USD20 per litre. The main concerns that were expressed by the local community was the fear that bamboo would rot, and the tank would disintegrate. However, INBAR was able to prove that treated bamboo can last 25 years or more, and the bamboo used for this water tank was therefore treated with a simple method using appropriate technology.
INBAR has published a manual to help other communities build similar structures, which is available on line: http://www.inbar.int/publications/?did=260.
The pilot project could not have been possible without the support from the Canadian Government. The results are very encouraging, and we hope to embark upon a second phase of testing and promotion in the coming year.