This report is one of several International Irrigation Management Institute (IIMI) publications that address the issue of irrigation management to promote diversified crops during the dry season. As Sri Lanka approaches self-sufficiency in rice production, a target already achieved by some of the countries in the region, there is no logic in using land and water resources, which could support higher value, non-rice crops, using less water. Thus a main incentive of the ‘improving irrigation’ system is to find ways to conserve water, and stretch its use further during the dry season. IIMI’s fascination with the Dewahuwa tank was prompted by the existing widespread adoption of non-rice crops during the Yala season, when there is very little rainfall. This report presents the organisational aspects of the new rotational plan that was introduced after the 1987 experiment by IIMI on improving water management.