History of Ringed Land Community
In the past, the area downstream from the three Kiso rivers, through which the Nagara River flowed into Ise Bay, was formed by flow nets of the Kiso, the Nagara and the Ibi, the courses of which changed whenever the area was flooded.
In 1609, early in the Edo period, a great embankment was built on the left bank of the Kiso River, surrounding Owari Province. Later, this embankment, some 50 km in length, was called "the Enclosure Levee." The Enclosure Levee was intended to protect the province from floods, and it also had a military role as a defensive wall against invaders from western Japan. However, restrictions associated with it, such as that "levees on the opposite bank in Mino Province should be 91 cm lower than the Enclosure Levee," resulted in frequent flooding in Mino, prompting the formation of "ringed land communities" in this region.
A ringed land community is a communal society bounded by a levee (the ring levee), built to enclose a community and its cultivated land entirely for the purpose of protecting them from floods. The levee was built by the inhabitants themselves, and the history of the development of ringed land communities is a history of the way in which these communities fought the ever-present threat of flooding.