Lake Naivasha is at the highest elevation of the Kenyan Rift Valley at 1,884 metres in a complex geological combination of volcanic rocks and sedimentary deposits from a larger Pleistocene Era lake. Apart from transient streams, the perennial Malewa and Gilgil rivers feed the lake. There is no visible outlet, but since the lake water is relatively fresh, it is assumed to have an underground outflow.
The lake had an average surface area of 139 square kilometres before 2010, which had increased to 198 square kilometres by 2020. It is surrounded by a swamp that covers an area of 64 square kilometres, but this can vary vastly depending on rainfall. It is situated at an altitude of 1,884 metres. The lake has an average depth of 6 metres, with the deepest area at Crescent Island, at a maximum depth of 30 metres. Njorowa Gorge once formed the lake’s outlet, but it is now high above it and forms the entrance to Hell’s Gate National Park. The town of Naivasha (formerly East Nakuru) lies on the northeast edge of the lake.
The lake is home to various types of wildlife, including over 400 species of birds and a sizable population of hippos.
