For crossing rivers flowing from mountains, construction methods such as sheeting board (level crossing), elevated flume (overpass above the river), and underground trough (overpass below the river) are constructed according to the conditions of the river. The weirs were made concrete by the Kamanashi River right bank land improvement project implemented from 1965 to 1973, but the positions and essential structures of the irrigation canals that have continued since the Edo period still remain in many places today. Currently, the Tokushima Weir is owned by the Ministry of Agriculture, Forestry and Fisheries, and its management is contracted by the Union of Land Improvement Areas on the Right Bank of the Kamanashi River. In addition to being used in the sprinkler nets laid in the paddy fields of Nirasaki City and the Southern Alps City and in the Midaigawa alluvial fan, the running water is also used for fire prevention in communities, flood control, and small hydroelectric power generation using water wheels. There is Reported to the National Council for Cultural Affairs and the Minister of Education, Culture, Sports, Science and Technology for new registration. On June 17, 2022, the National Culture Council positioned the Tokushima Weir as a cultural property suitable for national registration. This is the second registered monument in Yamanashi Prefecture, and the third nationally registered monument following Tachibai Canal (Taki Town, Matsuzaka City, Mie Prefecture) and Nikaryo Canal (Kawasaki City, Kanagawa Prefecture) becomes.
Tokushima Hyozaemon Toshimasa (year of birth unknown) was a merchant living in Fukagawa, Edo (present-day Koto Ward, Tokyo), and was apparently an avid follower of the Nichiren sect with a wealth of business talent. In the first year of Kanbun (1661), when Hyozaemon visited Mt. Minobu, he learned that Nishigoori, Koma County had a large area of land that had been left untouched due to lack of water. As a result of a field survey later, he dug a weir from Kamitsuburai to Kajikazawa to allow water from the Kamanashi River to pass through, and collected water charges (water usage fees) from the newly developed rice fields and fields converted into rice fields. I made a plan to manage with a rebate of the annual tribute. The feudal lord of the Kofu domain (1600) After the Battle of Sekigahara, Senchiyo Tokugawa, the adopted son of Chikayoshi Hiraiwa, the governor of Kofu, entered the domain, but died young in the same year. Yoshinao Tokugawa (the 9th son of Ieyasu) entered the domain...