The Evolution of Reservoir Irrigation Systems as Commons in the Dry Climate Region of Contemporary Japan

Abstract

"The purpose of this paper is to explain Japanese reservoir irrigation systems as commons through historical points and to present their transformation and contemporary challenges under industrial changes and urbanization. Also significance of the system is touched upon at the time of natural calamity and environmental threat. In Japan some regions have a fairly dry climate and are short of perennial rivers, and these have long adopted reservoir irrigation systems for rice cultivation from ancient times. Particularly in the areas facing the Seto Inland Sea (between the main islands of Honshu and Shikoku) to which Hyogo, Kagawa, Okayama and Osaka prefectures belong for example, there exist many such irrigation works. As is the case in the Asian monsoon region, rice farming under reservoir irrigation has the attributes of CPRs, requiring some level of joint management, and the social and institutional features of CPR-like practices among such systems are quite frequent. However, because industrial base of agriculture has been declining as economic structure shifts in Japan, quite drastically in the latter half of the 20th century, institutional arrangements in irrigation have also changed, resulting in inevitable alterations in the commons content. The paper begins by explaining the nature of system supporting water supply and irrigation technology. This paper then goes on to examine custom and practices undertaken in the areas of Japan with centuries of history in using reservoir irrigation and their changes. The paper concludes with thoughts about whether the commons can provide a significant basis even in the society of the present."