Effects of large multi-purpose dams on public health and food security: A case study of Masinga dam - Kenya

Abstract

Large multipurpose dam schemes are developed to provide reliable hydro¬electricity, improve food security, act as new centres of tourism, improve on transport and infrastructure and, improve on the social and economic well being of both the country and communities in their neighbourhood. It is within this perspective that the study was carried out to investigate the effects of Masinga dam on public health and food security. The study analyzed the relevant literature and concluded that, despite the fact that there are many studies on large multi-purpose dams, elsewhere in the world, and in Africa as well, the majority of these studies focus on impact of land use on the dams, but not, the effects of dams on public health, hence the need for this study. Primary data was collected by the use of questionnaires administered to a randomly selected sample of respondents, while, water samples were collected from three distinct areas of the reservoir, namely, the Riverines, Transisitional and Lacustrine zones for quality tests. Secondary data on health and fisheries was collected from District Records Health Office at Machakos Ministry of Health and Siakago Department of Fisheries Offices, respectively. These data, were analyzed and represented using various statistical methods of data representation. Regression analysis and cross tabulation were done to test relationships. The findings on water and sanitation, showed that majority of people in the study area use untreated water fetched from the dam. They also use the dam as source of water for their livestock. The perception of the community was that the dam is the main cause of their frequent illnesses. However, water quality tests showed the dam water does not exceed the Kenya and WHO standards limits for drinking water except iron which was beyond the limit. On waterborne diseases prevalence; generally, it was evident that most had higher prevalence nearer to the dam. Malaria had the highest prevalence followed by typhoid fever. Schistosomiasis (bilharzia) had also increased.

On food security, the dam has led to increase in the diversity of crops grown through irrigation. However, most of the foods grown under irrigation are vegetables grown up to 2.5 km from the dam, hence their impact in reducing food security is insignificant. The results on fisheries show that fish yields varied with season with highest catches reported during rainy seasons. The most common fish are, the Tilapia spp, second, the common carp and third, the clarias spp. The results show that these fish species had increased dramatically while the others have decreased over time. On human wildlife conflicts, the research found these to be serious, with crocodile and hippo attacks being the most prevalent. There was evidence that, wildlife conflicts caused by crocodiles and hippos that habit the dam disrupt peoples' livelihoods and contribute to increasing community food insecurity either directly or indirectly. On external intervention, the results showed that majority of people feel that the level of external intervention is not adequate. In conclusion, the study found out that most of the community members support the dam and are willing to participate in its conservation, if they are involved. Finally, the study provides recommendations to policy makers and and areas for further research ..