Characteristics and Management Issues of Irrigation Ponds, Categorized by Their Functions in the Ponds Group Water Use Network

Abstract

In this study, irrigation ponds in seven communities located downstream of the Dainichigawa Dam (Minami-Awaji City, Hyogo Prefecture) were categorized according to their functions in the water use network within the irrigation ponds complex. As a result, the irrigation ponds were classified into six categories based on the source and destination of water intake and distribution. The largest number of irrigation ponds in this area are "water catchment type", which take water from surrounding mountains and rivers and distribute it to other ponds, even though the area is the beneficiary area of a dam. The analysis of the location characteristics of each type and the questionnaire survey on the actual management of irrigation ponds showed that the "water catchment type" tends to be found in small ponds located on a slope and relatively far from the dam. On the other hand, the "relay type" and "utilization type" ponds, which take water from other ponds, are large ponds located relatively close to the plain, and are more likely to be managed in a continuous systematic manner. It was also shown that the "water catchment type" and "relay/utilization type" differ in the implementation of water fall as a countermeasure against heavy rainfall, and in the content of maintenance required in the future.