The lake covers about 765 square kilometres (295 sq mi) depending on the season, connected via the Irebu channel with the Congo River. Water may flow into or out of the lake through this channel depending on the floods. Lake Tumba has 114 species of fish and supports important fisheries.[2]
The lake lies at the center of the Tumba-Ngiri-Maindombe area, designated a Wetland of International Importance by the Ramsar Convention in 2008.[3]