Akimoto Lake - Overview

Overview

The lake itself did not exist as late as the Meiji period in the area now known as the "Inner Bandai Plateau", which was once the site of the village of Hibara. In 1888, Mount Bandai--which is located to the south—erupted, and part of the mountainside caved in as a result of the accompanying phreatic explosion; a large rockslide—and then mudslide—in the direction of Hibara destroyed the village. It was previously assumed that one large phreatic explosion had occurred, but the destruction of the mountain is now thought to have been caused by several medium-sized explosions.

Rivers like the Nagase River and Onogawa River that flow in the Inner Bandai area became clogged up due to the destruction of the mountain and mudslide; Lake Hibara, Lake Onogawa, Goshiki Marsh and other such dammed lakes were thus formed. Akimoto Lake was formed by the damming of Ōkura River and Nakatsu River. It is the deepest of the lakes in the inner Bandai tri-lake area, and is second to Lake Hibara in surface area.

Akimoto Lake’s water flows in from Nagase River, and forms a delta at its lower section which pours into Lake Inawashiro. Water then flows from Lake Inawashiro into Nippashi River, from which it connects to Agano River at Kitakata City. Because of this path that the water takes, Akimoto Lake is designated under the River Act as part of the Agano River water system, and managed as a class-1 water system by Fukushima Prefecture.