Lake Toya

About Lake Toya

A lake in the Toya caldera, formed by an eruption about 112,000 to 115,000 years ago. Nakajima Island in the lake and Mt. Usu are volcanoes that grew after the caldera formed. The 1991 survey recorded it as a lake that does not freeze in winter, with kokanee, Japanese smelt and Japanese dace, and wintering mallards, pochards and goosanders. According to the survey's data appendix, 2.94 km² of the lake had been reclaimed by the 1970s.

Sources: Japan Meteorological Agency, Caldera volcanoes (National Catalogue of the Active Volcanoes in Japan), Environment Agency of Japan, Lake Survey Report (1993), Environment Agency of Japan, Lake Survey Report: Data Appendix (1993) (sources in Japanese)

Lake data

Area

70.72 km²#4 in Hokkaido

Maximum depth

179.7 m#3 in Hokkaido

Average depth

117 m

Surface elevation

83.948 m

Transparency

10 m#6 in Hokkaidoas of the 1991 survey

Origin

Caldera lake

Lake type

Oligotrophic

Fresh or brackish

Freshwater

Freezing

Does not freeze

Unmodified lake

No

Natural park

Shikotsu-Toya National Park

Geopark

Lake Toya and Mount Usu UNESCO Global Geopark

Lake number

1120number in the national lake survey

Sources: Geospatial Information Authority of Japan, Area Statistics of Prefectures and Municipalities 2026 (as of July 1), Geospatial Information Authority of Japan, Lake Survey (surveyed 1968-1969), Environment Agency of Japan, 4th National Survey on the Natural Environment: Lake Survey Report (1993). Area and depth use newer figures from the Geospatial Information Authority of Japan where available. Origin, lake type, transparency, freezing and unmodified status are as of the 1991 survey.

Themes that include Lake Toya

• Caldera lakes
• Oligotrophic lakes
• Freshwater lakes