Kahe Ward, Tanzania
Photograph and Narrative Provided by Chris de Bont
In the Kahe ward in northern Tanzania, farmers have started using shallow groundwater to grow (commercial) crops. Wells are hand-dug and about 7-15 meters deep. Some farmers dig their own well, but many ask for advice from experienced well diggers. The picture shows a tool used by a well digger from the village of Oria. He uses a larger version of this tool to break through stony layers when digging shallow wells for irrigation and domestic use. Over the years, he gained experience in siting and designing the wells he digs in his community.
In siting the well, he looks at the topography and the soil type. Explaining his reasoning, he says: “I look at the streams of sand. If you dig in one of those sandy streams, you will easily get clean water. On the farm, you look where in the farm there is a depression”. These characteristics, he says, indicate where there were river courses before, and therefore where the water is. Others say that fig trees are good indicators of groundwater availability, but he disagrees: these trees do not grow in rivers, but rather next to them. So the presence of a fig tree indicates a former river bank, not the actual river.
In designing the well, he makes use of experience he got from working at construction sites in other cities in Tanzania. He makes the wells circular, because this makes them more stable. He also digs a second hole next to the well, a so-called chamber, so that the pump can be places closer to the water level. Over the years, this design has become dominant in the ward.