In a region where access to safe, affordable water is limited, manual drilling provides a cost-effective way of tapping groundwater resources. However, aquifers are complex and striking fresh water is not guaranteed.
Fussi and his team propose a model that uses analysis of borehole logs for the to characterise shallow aquifers so that areas suitable for manual drilling can be found. The model is based on available borehole-log parameters: depth to hard rock, depth to water, thickness of laterite (a iron-rich rock type common in the tropics) and hydraulic properties of the shallow aquifer. The model was applied to a study area in northwestern Senegal.
The hydraulic conductivity values – how easily water flows through rock – were estimated from geological data and partially validated by comparing them with measured values from a series of pumping tests carried out in large-diameter wells.
The results show that this method is able to produce a reliable interpretation of the shallow hydrogeological context using information generally available in the region.
The research contributes to improving the identification of areas where conditions are suitable for manual drilling, and has the potential to be used throughout Africa, and beyond, using data available in most African countries.
Ultimately, this work will support proposed international programs aimed at promoting low-cost water supply in Africa and enhancing access to safe drinking water for the population.
There are three urban areas in which T-GroUP is active and, while most of the drilling activities in Dodowa and Arusha have been completed, in Kampala it took some time to get permissions. At first, the Ministry of Water and Environment had to formally approve the project drilling activities, which they did. Then, the Kampala Capital City Authority required more information about the project before giving their formal go-ahead. Thirdly, the Local Councils had to be convinced of the usefulness of the work, and, finally, land owners and tenants had to approve of the installation of piezometers on their land for monitoring purposes. It took Dr. Robinah Kulabako and Dr. Philip Nyenje a good deal of energy to take all hurdles. But they finally succeeded! The process also served as a good and thorough entrance of the project into the local communities. On Wednesday April 6, PAT Drill Uganda started drilling the first hole near Makerere University towards the top of Makerere hill. While drilling, the team was visited by David MacDonald and Dan Lapworth of BGS, who were in Kampala in the framework of the HyCRISTAL project within the NERC/DFID funded Future Climate for Africa Programme.
Meanwhile in Kampala, Dr. Philip Nyenje and Dr. Robinah Kulabako had gone to request permission to drill at the Church premises on Makerere Hill going down to Bwaise slum. Permission was required in order to be able to install a transect of piezometers between Makerere Hill, the perceived groundwater recharge area, and Bwaise slum, the groundwater discharge area. After introducing T-GroUP, they had good discussions with the Vicar of the church regarding the project, community mobilisation and other ideas in the field of water supply. Then, the Vicar requested Philip and Robinah to formalise their request in writing and deliver to him the letter. Additionally, he also requested Robinah to be a Guest Speaker during Mary’s day at his church. Robinah was happy to take up this challenge, as she regarded it not only to be an opportunity to strengthen and augment collaboration within the project and between the project and the community, but giving a sermon would also contribute to shaping Robinah spiritually.
The sermon was on “Living Wisely” based on Ephesians 5:15-17. Robinah really enjoyed it and she was happy to do the needful, combine religion with science, and get permission to drill.
Two presentations followed extensive discussion. Groundwater risks and institutional responses in Kwale, Kenya (Jacob Katuva, Oxford University) and From Codes of Practice to a Code of Conduct – groundwater governance in Kenya from a drillers perspective (Tom Armstrong, JB Drilling). Practical issues of borehole design and construction, groundwater quality, gender and poverty as well as the realities of the Water Resource User Associations (WRUAs) in Kenya, and plans of the Kenya Water Industry Association (KWIA) were discussed.