The potential for modernizing and improving tank (small reservoir) irrigation in the Indian state of Tamil Nadu is assessed. After reviewing tank irrigation in Tamil Nadu and the problems affecting its performance, the report examines irrigation in the drought-prone Ramanathapuram District (where there is a large concentration of tanks), focusing on climate and rainfall, irrigation sources, soil conditions, land use and cropping patterns, and farm labor. Data collected via interviews with farmers and officials on the characteristics and performance of 10 tanks of varying dimensions in the District are presented, covering, inter alia, tank scale and type; tank water supply, distribution, and management; encroachment; sluice location; and the role of water user organizations. It was found that 7 of the 10 tanks have inadequate water supplies 50-70% of the time and that a third of the farmers use supplemental water from wells. Two models - production function and simultaneous equation - are employed to measure the impact of varying water conditions on rice production; both reveal the critical importance of adequate irrigation water. Finally, channel lining and community wells are proposed as means of improving tank irrigation. A summary of findings and suggestions for further rehabilitation and research efforts concludes the report. Included are 37 tables, 5 figures, the production function model, and a 4-page bibliography (1935-82).