The critical nature of clean water supplies in many parts of the world, and particularly in the least industrialised areas, has long been a matter of worldwide concern. It has been acknowledged that much of the health and economic problems of such countries could be attributed to poor water resources, and encouragement has been given to improving this state of affairs. One of the rasons that the Workshop on Limnology and Water Resources in the Developing Countries of Asia and the Pacific was arranged was to review those countries current technical position. It was apparent at the Workshop that there is no single policy which can be of general use to sustaining clean water in such a wide region, but different conditions must lead to different approaches. Local technical skills, as distinct from imported opinions, are crucial to develop appropriately separate lines, and the following pages illustrate the extent to which they exist at present. It is left to the reader to decide which parts can be selected as an aid to his particular needs. The proceedings also showed that there is much to learn from relevant experience in the industrially developed parts of the world, which is evidently often missed in the normal conduction of experimental work on water resources in Asia. The presentation here of contributions from a very wide variety of origins makes some remedy for this, but clearly a more efficient flow of up-to-date information is something exposed as a need. The value of coordinated policies and accentuation of multi-purpose water usage, which reduces the dependence upon sophisticated and expensive technology was perceived by many contributors. The transferring of such approaches to public opinion and hence to government can be as an avenue of future effort.