Epistemological value of irrigation history To sum up, Southeast Asia’s historiography is replete with the facts pointing to a wide range of human activities centered round the lowlands, thanks to their agricultural potentialities for supporting the bulk of the population and sustaining the political power in various parts and at different times of history. The vagaries of tropical monsoon rhythm, invariably manifest in spatio- temporal variations in the rainfall distribution, warranted the development of water schemes of various degrees of sophistication by the organized labor of the local people. Evidently, the minor irrigation works termed as hydro-agriculture, essentially those undertaken by local people, had the capacity to meet the demands of wet rice cultivation for several ensuing centuries and thus outlived the state. On the other hand, the state-accomplished large-scale irrigation and drainage works, signifying the major irrigation schemes, were based on the techniques of hydraulics. All these multifarious irrigation works of great antiquity, though reckoned as primitive and crude, have amply testified to their efficacy of serving the peasant community and the state to bolster up its political image and authority. It is also an undisputed historical fact that these rudimentary irrigation methods have survived even the development of some modern irrigation projects from the beginning of 20 th century.
