A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand

Thesis (M.Eng.) - Asian Institute of Technology, 1979

By the end of 1985, a great number of small reservoir are to appear in areas of Northeast Thailand that are inaccessible from large reservoirs and reliable rivers. The small reservoirs as well as large tanks and small dug ponds or weirs will supply basic village water requirement. The present study is thus focused on these small reservoirs for their economic feasibility. Two models are formed after investigating demographic pattern and land holding pattern of the region, basic water requirement, possible agricultural activities and related revenues. Water requirements, production cost of and benefit from paddy, some dry season crops and fish raising in the reservoirs are studied in details, i .e . in Annex 1, 2. Appraisal of the two models of 100,000 m3, 300,000 m3 , 600,000 m3 and 1,000,000 m3 reservoirs are carried out at financial level to demonstrate their economic feasibility. Under favorable conditions, that is to say when the reservoirs are properly designed and constructed on good site, modern agriculture is practiced under proper planning and management, and public services and market are available, both models of four sizes of reservoir yield the internal rates of return (IRR's) of 12% to 30%. 3 The bigger reservoir, the more revenues can be expected and 100,000 m is the minimum size that allows beneficial activities. Provided that the demand is not limited, dry season crops and fish raising in the reservoirs are the best choice to render the small water reservoir project profitable.