Lake Naivasha

Lake Naivasha is a freshwater lake in Kenya, outside the town of Naivasha in Nakuru County, which lies north west of Nairobi. It is part of the Great Rift Valley. The name derives from the local Maasai name ɛnaɨpɔ́sha , meaning "that which heaves," a common Maasai word for bodies of water larger enough to have wave action when it is windy or stormy. Naivasha arose as the British attempt to pronounce the Maasai name. Literally, Lake Naivasha means "Lake Lake." Lake Naivasha is at the highest elevation of the Kenyan Rift valley at in a complex geological combination of volcanic rocks and sedimentary deposits from a larger Pleistocene Era lake. Apart from transient streams, the lake is fed by the perennial Malewa and Gilgil rivers. There is no visible outlet, but since the lake water is relatively fresh it is assumed to have an underground outflow. The lake had a normal surface area of before 2010 and had increased to 198 square kilometres (76 sq mi) by 2020. It is surrounded by a swamp which covers an area of , but this can vary largely depending on rainfall. It is situated at an altitude of . The lake has an average depth of , with the deepest area being at Crescent Island, at a maximum depth of . Njorowa Gorge once formed the lake's outlet, but it is now high above the lake and forms the entrance to Hell's Gate National Park. The town of Naivasha (formerly East Nakuru) lies on the north-east edge of the lake. The lake is home to a variety of types of wildlife including over 400 different species of bird and a sizable population of hippos. The fish community in the lake has been highly variable over time, influenced by changes in climate, fishing effort and the introduction of invasive species. The most recent shift in the fish population followed the accidental introduction of common carp in 2001. Nine years later, in 2010, common carp accounted for over 90% of the mass of fish caught in the lake. There are two smaller lakes in the vicinity of Lake Naivasha: Lake Oloiden and Lake Sonachi (a green crater lake).