Browsing by Author "Kaduma, Josephine Diana"

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    Man-made lakes: their social economic and ecological impacts: the case in Tanzania
    (University of Dar es Salaam, 1977) Kaduma, Josephine Diana
    The creation of man-made lakes have become a popular method of developing the water resources of river basins the world over. The purposes for their creation vary from flood control, irrigation, navigation, fishing and hydro-electric power production. Their impacts to the people and areas in their vicinity are similar. The planning, construction, operation and maintainance procedures are also similar. Hence earlier cases provide useful lessons to the later ones. This study examines the influence of man-made lakes on man's environment and on his social and economic ways of life. While man-made lakes have been constructed successfully in some developed nations, in Africa, their planning has omitted many social and environmental aspects. Consequently, various problems to both the people and the economic and / or ecological planners have been experienced. By studying five large man-made lakes in other African countries, the thesis shows how their planning and problems are similar to those of man-made lakes in Tanzania. Nyumba ya Mungu lake, the first man-made lake in Tanzania is studied in detail showing similarities to the five lakes. Its planning and implementation processes are examined showing omissions, failures, successes and achievements. An attempt is made to show where Nyumba ya Mungu experiences are being used in the planning of other man-made lakes in Tanzania and where similar mistakes are being made. The thesis observes with concern that in spite of earlier experiences, planning of new man-made lakes in Tanzania still places a great deal of emphasis on the production of hydroelectric power at the expense of other water requiring activities. The multi-purpose approach is used only as a means of satisfying the economic justification analysis. Pangani and Rufiji river projects are used to illustrate the adherence to this tendency. In an economic analysis, costs and benefits are given monetary values to facilitate comparisons. In a country like Tanzania, it is difficult and sometimes impossible to quantify many benefits accruing from a water resource development project hence the relevance of the analysis becomes questionable.
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    Some development and economic aspects of the Mindu Dam project, Morogoro: a background analysis for decision making
    (University of Dar es Salaam, 1972) Kaduma, Josephine Diana
    The Mindu dam project is a development project in the upper Ngerengere basin near Morogoro town. Currently the project’s aim is to store the water of the upper catchment of the Ngerengere River during the rainy season to be used for supplying present and future urban, domestic and industrial water needs as well as rural domestic and irrigation needs. Back in 1956, the project justification was to store water for the use of the sisal estates downstream the dam site, kingolwira prison farm and for the irrigation of 400 hectares. In 1967 the project’s purpose was described as partial flood control, rural domestic and livestock water supply during the dry season and possibly provision of irrigation water. A study of the Ruvu basin (Appendix A) 0f which Ngerengere is a sub-basin, revealed that several proposed projects with engineering feasibility had no economic feasibility study. It was laterfound out that an economic feasibility study was one of the desirable studied to be carried out before implementation of a project. The thesis attempts such a study for Mindu dam project. A survey of the Morogoro urban water supply revealed that the present water source, even after extension, is incapable of supporting the urban population as well as the proposed industries by the end of 1972. Therefore a new source of water supply was absolutely necessary by the beginning of 1973. By 1970, Mindu dam was the only known way to provide this much needed water. By 1974, the urban population would require an extra 2.25 million litres per day while the industries would require 6.75 million litres per day. A census on the rural population revealed that 600 people will be displaced by the reservoir. These, plus other 400 will require improved water supply (quality wise) as at present they are totally dependent on the polluted Ngerengere River. A soil survey below the dam site revealed that 800 hectares with sandy, loamy and clayey soils could be put under irrigation agriculture. Fishing from the reservoir might be an additional benefit but this is difficult to evaluate at present. A survey was carried out on the rural population’s feelings on improved water supply. It was found out that more than 64% would welcome the improved water supply system while 32% did not like it. Some amount of health education as well as political education is necessary to convince this 32% of the benefits of improved water supply. It was found out that only 10.6% of the total population wanted to be settled in an ‘ujamaa’ village and only 8.6% wanted to cultivate or do business ‘kiujamaa’. Therefore only compensation costs arising from the lossof permanent property like houses and tree crops were assessed and not costs arising from resettling the people in a planned settlement (ujamaa village). The costs for the construction of the reservoir and distribution system were found to be 12,500,000 shillings while maintenance and operation costs were found to be 250,000 shillings per year. Compensation costs were found to be 465,210 shillings. The direct returns from urban water supply were found to be 1,916,250 shillings per year by 1974. 100,000 shillings per year in 1974 can be written off as direct return from the rural population. Direct benefits from irrigation and fishing were estimated at 1,500,000 and 100,000 shillings per year respectively. The above information was used to assess the project’s economic worth. The costs were weighed against the benefits and a benefit-cost ratio of 5:1 was obtained as discussed in detail in chapter 6.