Despite continued efforts, in the Democratic Republic of Congo (DRC) only 52% of its population having access to a water point in 2015, and even less in rural areas.
To find low-cost solutions, UNICEF has implemented in 2012 a programme in order to professionalize the manual drilling sector. But an effective strategy for development of manual drilling requires the identification of areas with favourable hydrogeological conditions.
The methodology used in this work derives from UNICEF experience in 16 other African countries and a research project in Guinea Conakry and Senegal managed by the University Milano Bicocca . It is based on the integration of existing data, together with field experiences of local technicians.
The aptitude to manual drilling derives from the combination of:
- The feasibility : possibility of drilling using manual techniques
and of reaching an aquifer. It has been estimated from the depth of
rock and the depth of water
- The potential for exploitation : semi-quantitative assessment of potential yield estimated indirectly from the thickness of coarse layers in the exploitable aquifer
- The presence of partially hard layers that increase time and cost for
The procedure for the estimation of the aptitude for manual drilling at national level has been carried out through these steps: 1) collection of available data and stratigraphic logs; 2) organization and standardization of data in a specifically designed database; 3) estimation of hardness and permeability for regular intervals of 1 m, using a semiautomatic method; 4) extraction of a set of hydrogeological parameters; 5) estimation of the class of feasibility, potential and difficulty of perforation for each drill; 6) extrapolation of feasibility and potential to the whole country on the basis of geological map and morphology; 7) comparison with the direct expertise of drillers and water technicians.
The majority of the territory is located in areas favourable to manual drilling (42% classified with high or very high aptitude, 24% moderate), especially in the western part of the country, covered by thick loose layers. On the other hand, in the east of the country there is a strong presence of cristalline rocks that form favourable discontinuous alteration layers.
One of the main contributions of this project is the creation of a database at a national level in which the information used and generated is collected and organized.
Manual drilling currently exists in several areas of the country, but is also non-existent in some provinces despite their favourable or moderately favourable conditions for manual drilling. The dissemination of this technique can improve the access to water.
Indeed, the database is designed as a dynamic tool that, regularly updated, is an important support for groundwater resource management.