Drilling for water can be expensive: it can cost up to £10,000 to drill a borehole that will have a £500 handpump installed on it. However, there are alternatives – manual drilling methods are often most effective and just as good quality, but the challenge for the drillers is knowing where they can find good quality water.
The Catalyst project led by the University Milano Bicocca (Use of remote sensing and terrain modelling to identify suitable zones for manual drilling in Africa and support low cost water supply) has been looking at how data from satellites and other remote sensing sources can map groundwater conditions in West Africa to identify good areas for manual drilling.
Fabio Fussi presented their work at the 37th WEDC Conference, in Hanoi, Vietnam. Because the Ebola outbreak in Guinea, Sierra Leone and Liberia, work has focused on Senegal. Here, the researchers have mapped and identified two zones that are suitable for manual drilling. A common problem in tropic regions is ‘laterite’ a hard layer of soil under the surface. If it is too thick then a manual percussion rig will struggle to pierce it. However, this project has not identified this as a major obstacle. A bigger concern is the depth of the groundwater, which in some areas may be too deep to be reached by manual drilling, which can usually only reach down 50 metres or so.