The type of farming in the Nara Basin had already been established before the start of the modern period. The Nara Basin boasted Japan’s highest capacity for producing rice. However, water rights disputes often occurred because of breaches of those water rights due to the limited amount of irrigation water available for use in farming. This paper examines the water rights disputes that were a part and parcel of the irrigation system in use in the early modern Nara Basin, and will proceed through the following methods: First, the author classifies the types of water rights disputes by examining historical water rights dispute materials. Second, the approach is taken of examining the relationship between any patterns in the results and where the disputes occurred. In this paper, in order to objectively understand exactly where the disputes occurred, the places where they occurred are classified by landform. The first subject involves classifying the disputes by those where the generating factor of the problem was resolved and those where it was not. It is understood that the generating factor in the former was problems that arose because of natural factors such as water shortages and floods, and artificial factors such as repairs made by villagers.
The second subject concerns the relationship between the generating factor and the type of landform, examination of which reveals disputes to have been due to water shortages as they occurred on the alluvial fans, while floods, water shortages, and repairs were revealed to be factors when they occurred on the flood plain.
Thus this clarifies that shortages of water and drainage problems had occurred on the flood plain, while a shortage of water was the main matter with regard to the alluvial fan. The reason why the problems on the flood plain were so diverse is because use of the water supply facilities involved differing irrigation and drainage systems being used by each village, which then resulted in complicated irrigation customs. Conversely, disputes involving the irrigation ponds often occurred on the alluvial fans. Because there were few usable water sources in the vicinity, irrigation ponds became the main water source.
