Abstract

Access to adequate potable water is still one of the critical problems facing the rural population in Malawi. A number of instruments and strategies have been formulated to address the water accessibility problem. According to the National Strategy for Sustainable Development, 2004, construction of small earth dams is one of the strategies that has been adopted to improve access to potable water for domestic use by 2015. This study assessed the reliability of six small earth dams for domestic water supply in Traditional Authority Kalolo in Lilongwe District in Central Malawi. Flow Duration Curve (FDC) Analysis was employed and water quality assessments (colour, pH, iron, nitrates, sulphates, phosphates, potassium, faecal coliform, and total dissolved solids) were employed in order to determine adequacy of water and extent of water pollution in the dams, respectively. The ecological management classes of the dams were established using Rapid Assessment / Determination Method, which is done to set an ecosystem into a class as a function of the flow.The study revealed that all the six dams under study were unable to meet the communities’ water requirements for about 80% of the time. Considering that the small dams in the area were perched on dambos with minimal recharge from adjacent aquifers and that pattern of flows depict the dependency of the dams on surface flow with high flows in the rainy season and very low flows in the dry months, the dams were unable to viistore adequate amounts of water to meet the water requirements of the communities. Key informant interviews confirmed the inability of the dams to provide water for all year round. Dam location problems were alleged to be the major cause of 44% of the dams in the area not to be functioning. The small earth dams in the study area were found to be moderately to largely modified from the pristine state, thereby negatively affecting the quality of water in the dams. Faecal coliform counts in the water were found to range between 600 and 3000 counts, greatly exceeding the recommended counts in the Malawi water quality standards, thereby rendering water from the dams unsuitable for drinking without prior treatment. Water quality assessments revealed significant seasonal dependency. Biological water quality deteriorates during the rainy season due to increased run off into the stream and dams. In view of this, prior treatment of the water is required before the water from the small earth dams can be used for domestic purposes. The study proposes that dam designs should meet appropriate engineering and environmental standards encompassing hydrological, geological, ecological and socio economic factors, if the small earth dams are to result into long term outputs.

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School	: School of Natural and Applied Sciences
Issued Date	: 2010

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