This article may be expanded with text translated from the corresponding article in Japanese. (December 2008) Click [show] for important translation instructions. View a machine-translated version of the Japanese article. Machine translation like DeepL or Google Translate is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary Content in this edit is translated from the existing Japanese Wikipedia article at [[:ja:八ッ場ダム]]; see its history for attribution. You should also add the template ((Translated|ja|八ッ場ダム)) to the talk page. For more guidance, see Wikipedia:Translation.
Yanba Dam
LocationGunma Prefecture, Japan
Coordinates36°33′25″N 138°42′51″E / 36.55694°N 138.71417°E / 36.55694; 138.71417Coordinates: 36°33′25″N 138°42′51″E / 36.55694°N 138.71417°E / 36.55694; 138.71417
Construction began1967
Opening date2019
Construction cost532 Billion Yen
Dam and spillways
ImpoundsAgatsuma River
Height131 m
Length336 m
CreatesLake Yanba-Agatsuma
Total capacity107,500,000 m³
Catchment area707.9 km²
Surface area304 hectares

Yanba Dam (八ッ場ダム, Yanba damu) is a dam in Naganohara, Agatsuma District, Gunma Prefecture, Japan. Construction began in 1967, with effective completion in October 2019 and the official opening on 1 April 2020.

Planning for the dam began in 1952, and it was planned to be completed by 2015. The dam's construction had seen sustained local opposition and a ballooning budget, and a change of National government in 2009 resulted in the project being halted, being about 70% completed at the time. Another change of government in 2012 resulted in the project being revived and subsequently completed.

Construction required the relocation of part of the Agatsuma Line, several roads and affected residents.


This article incorporates material from the corresponding article in the Japanese Wikipedia.