Farming fields of “Jori” system have overspread at alluvial fans in the foot of Minou mountain ranges of middle reaches of the Chikugo river from ancient times. And at the bottom lands the irrigation water courses were constructed in Edo period.
Irrigation systems have been changed to those of concrete structures, using pumps or pipelines under the national irrigation development works. This study traces the transition of irrigation systems in order to find the characteristics of traditional water control systems in this area. The following findings are obtained:
1) Various systems have spread reflecting the characteristics of 1) p laces respectively.
2) Systems have changed to macro-type after the time of high level of economic growth, in 1950's.
3) The “Motase” has been operated as a traditional irrigation system.
4) Unlike modern techniques, the distinctive feature of traditional irrigation system is that the structure contains the constructing process and expresses rythms of the nature.
