Mini hydro plants were first installed in Sri Lanka at the end of the 19^th Century, to provide mechanical and dc power to the tea estates. By the middle of the 20^th Century grid supplies had reached the tea factories and, by 1970, most of the mini hydro plants had fallen into disuse. In the 1980's a weak grid almost entirely dependent on hydro-electricity and a number of dry years, caused prolonged periods of power shortages and interruptions to the electricity supply. These occurred all over Sri Lanka and, in particular, in the rural areas where the tea estates were situated. This, among other reasons, lowered the quantity and quality of tea production, and caused considerable economic difficulties in a country whose main export is tea. Managers of the tea estates started to look for more reliable, stand-alone sources of power. A number of feasibility studies of mini hydropower were undertaken on the estates but very few led to plants being installed. This thesis contends that mini hydropower is an appropriate and needed source of energy on the tea estates in Sri Lanka. It looks at the history, politics, geography and hydrology of Sri Lanka in the context of their effect on hydropower development in Sri Lanka. It discusses the process of tea manufacture and the suitability of the use of mini hydropower as a source of energy in the factory, as a source of rural electrification for the estate workers and as a diversification by selling surplus to the Electricity Board. Previous feasibility studies in mini hydropower, both international and national, are considered and appraised. This information was mainly collected on extended field visits to Sri Lanka. Over twelve months was spent in the country gaining the knowledge and expertise that was embodied in software used to survey a considerable number of sites in the tea estates. The further knowledge gained in this surveying process is discussed, results are given and conclusions drawn which suggest a strategy and methodology for the expansion of the mini hydropower capacity and industry in the tea estates of Sri Lanka.