Oigawa Irrigation Canal

...Power generation is progressing in the Oi River basin, taking advantage of the high annual precipitation of around 3,000 mm and the steep gradient of the terrain, with the entire river system, including Chubu Electric Power's nine power plants, generating approximately 600,000 kW of electricity at maximum output. The river's water is also used for the Oi River Irrigation System, which was implemented as a national and prefectural project, and is sent to the rice paddy areas of Shida, Haibara, and Nakato districts on both banks, and the abundant groundwater in the Kawajiri area of ​​Yoshida Town near the river mouth is used for eel farming. [Matsumoto Shigeki]
[Oi River Crossing]
A popular song goes, "You can cross the Hakone 8 ri on horseback, but the Oi River is impossible to cross," and the Oi River, which flows along the border between Suruga and Totomi, was considered a difficult spot on the Tokaido.

*Some of the terminology used in reference to the Oigawa Irrigation Canal is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…大井川流域では年間3000mm前後という多量の降水と地形の急こう配を利用して電源開発が進んでおり，中部電力の大井川水系9発電所など水系全体では最大出力で約60万kWの発電を行っている。またこの川の水は，国･県営事業として施行された大井川用水にも利用され，左右両岸の志太（しだ）･榛原（はいばら）･中遠地区の水田地帯に送られており，さらに河口近くの吉田町川尻一帯では豊富な地下水が養鰻に利用されている。【松本 繁樹】
［大井川の渡］
　〈箱根八里は馬でも越すが越すに越されぬ大井川〉と俗謡にうたわれているが，駿河･遠江の境を流れる大井川は東海道の難所とされた。…

※「大井川用水」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報