The Kabu-ido system and factors affecting local groundwater extraction control: case study of a customary groundwater management in Japan

In the early 1800s, a water conflict occurred in a community named the Fukuzuka Ring Levee on the Noubi Plain, Japan. Upper villages required artesian wells for irrigation and domestic uses, but lower villages did not welcome them because drainage from the wells caused impoundment damage to their paddy fields. The Kabu-ido system was a set of rules, including regulation of the number of wells per village, introduced to de-escalate the conflict. Under the system, groundwater uses were controlled not by external authority, but by the community residents themselves. This paper has two purposes. First, it reconstructs the daily operations of the Kabu-ido system, principally by referring to surviving local diaries, to describe hitherto unknown details regarding the management of groundwater by local people 200 years ago. The diaries show that well managers, selected from residents, regulated the use of wells using various tools, including permission and surprise inspection. Second, this paper evaluates to what extent self-imposed numerical regulation was successful by checking the number of wells listed in village expenditure notes. The documents indicate that regulation did not always work. The factors underlying this are considered using the analytical framework from the commons studies. Analysis shows that, while institutional arrangements of the Kabu-ido system, such as well management with keys, rules of joint responsibility, and the prohibition of indoor wells, work positively in enforcing numerical regulation by lowering the costs of monitoring for unauthorized wells, the natural characteristics of groundwater and climate conditions such as sudden drought work negatively.