This study aims to clarify the specific situation of waterways in the castle town Saga, focussing on their sustainable development. The results are as follows: 1) Waterways are specific fundamentals entirely necessary to the development of the town in lowland alluvial plains. 2) Existing waterways are built in the former castle town area with the basic and sustainable network repeating the pattern of waterway-road. 3) Existing waterways serving only as the enclosure of the social settlement unit can be divided into two types of meanings for the town life; the communal and personal availability. 4) Visibility to waterways essential for the future development will be obtained from two types of place; view from spots and linear view.
