Designing Effective Rainfall Harvesting Systems in Developing Areas of Sub-Saharan Africa

This paper examines the design of rainfall-harvesting schemes that could be implemented to improve the availability of water in certain developing regions of sub-Saharan Africa. The focus of the paper is on the evaluation of rainfall distribution patterns in parts of Sub-Saharan Africa. Rainfall harvesting is a sustainable water supply alternative in the developing, as well as in the developed countries of the world. In the developed regions domestic rainfall harvesting is primarily a means for supplementing other sources of water (usually for non-potable water uses). This paper also highlights the activities of non-governmental organizations in the development and implementation of in-country (location specific) appropriate technologies for water supply. These groups fund and implement small projects which solve basic water and environmental engineering problems in small communities in developing areas. Usually the goal is to use in-country appropriate technologies to formulate innovative solutions to problems. In a recent study, the National Research Council, identified integrated water management as a high priority development requirement in its list of emerging technologies that would benefit farmers in Sub-Saharan Africa and South Asia. The study also stressed the need to address water shortage and access to water resources in Sub-Saharan Africa. Furthermore, the World Health Organization (WHO) estimates that the number of people without access to water services will increase from 300 million (in 2003) to 400 million by the year 2020. This paper will also provide an overview of the water resources inventory and distribution in Sub-Saharan Africa to emphasize the need for small-scale, community based water supply alternatives for developing areas in this region. The paper focuses on implementable solutions particularly tailored for the region. These solutions are termed "location-appropriate" and therefore employ locally available resources, whenever possible, to achieve solutions that are cost- effective, sustainable and efficient. It addresses the need to analyze the temporal and spatial variation of precipitation in the design of viable rainfall harvesting systems.