Abstract
A project of the farmland improvement in the lower Chikugo river was started on a large scale of 55,000ha on both sides of the Chikugo river in Fukuoka prefecture and Saga prefecture. This project enforced abolition of the irrigation system of back current fresh water, reorganization of the creek networks and consolidation of farmland for machinery agriculture. This has caused dramatic changes to the geography of this region. The most serious problem concerns the fact that the distinct characters of the environment, its history, its ecology and the principles of water control in the region have been overlooked. Then following is necessary to solve the problems. 1. To apply the principle of traditional water control system that consists of points, lines and faces --- so called "Motase" system. 2. To bring up multiple inhabitants' groups and associations who maintain the water environments and regulate each other. 3. To create green water's edges, biotopes, ecological and human spatial order, and to regulate creeks around settlements. 4. To hold acknowledge and experience about water in common, and to succeed them and good environments to the next generation.
