Groundwater and Climate in Africa (Proceedings of the Kampala Conference, June 2008) IAHS Publ. 334, 2009. 103 Monitoring groundwater resources in Sub-Saharan Africa: issues and challenges S. M. A. ADELANA Department of Geology, University of Ilorin, Ilorin, Nigeria sadelana@gmail.com Abstract Over the last five decades the growing demand for freshwater has created water shortages in many parts of the world. Reliable assessment of groundwater resources, required to supply rapidly growing populations in Africa under a changing climate, places extraordinary demands upon the field of hydrogeology. The limited knowledge of groundwater resources on a national scale hampers development and managed use of this resource in many countries of Africa. Effective management of Africa’s groundwater resources is therefore challenging under these conditions and requires improved monitoring of groundwater resources. While new solutions are needed to meet future water demands globally, critical shortfalls exist in Africa of sustained monitoring of basic hydrogeological parameters. This paper reflects on the shortfalls in the designs, construction and maintenance of groundwater databases and presents case studies that employ monitoring data with current challenges in modelling groundwater use in Africa. Prior to identifying possible strategies and cost-effective techniques for groundwater monitoring, cognizance of constraints and considerations such as responsibility and funding is considered in this study. Proposed strategies consider the level of information required at country- and continent-scale, available resources, monitoring frequencies, funding and the use of a pilot-scale study to initiate national or continent-wide monitoring networks. Key words groundwater database; resource monitoring; groundwater management; Sub-Saharan Africa INTRODUCTION Groundwater supplies over 70% of Africa’s water supply systems; both economic development and poverty reduction imperatives drive the development of groundwater resources across Africa (Adelana & MacDonald, 2008). Groundwater has long been considered a reliable and readily adaptable source for rural water supplies. This has contributed, in part, to the heavy reliance upon groundwater for rural water needs. In Africa many cities where there has been considerable dependence upon surface-water reservoirs, are augmenting or planning to augment their water supplies with groundwater-fed systems due to increasing demand and deteriorating quality of surface water. Indeed, growing demand for freshwater is creating water shortages in many parts of the world, Africa included. Reliable assessments of groundwater resources, required to supply rapidly growing populations in Africa under a changing climate, places extraordinary demands upon the field of hydrogeology. Limited knowledge of groundwater resources on a national scale hinders development and the managed use of this resource in many countries of Africa. Effective management of Africa’s groundwater resources is therefore challenging and requires a reliable groundwater monitoring network. This paper reflects on the shortfalls in the designs, construction and maintenance of groundwater monitoring networks and considers model case studies that employ monitoring data. The approach adopted is to review the factors preventing availability of basic hydrogeological data, the underlying technical concepts, and necessary steps to ensure effective and continuous data monitoring. BASIC GEOLOGICAL AND HYDROGEOLOGICAL BACKGROUND Most of Africa is a series of stable, ancient plateaux, low in the north and west and higher (rising to more than 1830 m) in the south and east. The plateaux comprise mainly of metamorphic rocks that have been overlain in places by sedimentary rocks. Most of Sub-Saharan Africa (SSA) is characterized by low relief, high evapotranspiration and low groundwater baseflow and recharge (Wright, 1992). The geology and hydrogeology are also highly variable: 34% of Africa comprises heterogeneous Precambrian basement; 37% consolidated sedimentary rocks; 25% unconsolidated Copyright © 2009 IAHS Press