Lake Langano is in East Shewa Zone. It is one of a group of lakes in the middle of the Ethiopian Great Rift Valley, about 55 km south of Zeway. The main source of water, via several small rivers, is from the Arsi mountains (which form the eastern wall of the Great Rift Valley). Water flows from the lake via the Horo Kelo river into nearby Lake Abijatta (within Abijatta–Shalla Lakes National Park, site ET048). The lake is 23 km long, has a maximum width of 16 km, and is up to 46 m deep. There are two islands, one with hot springs, and both visited regularly by people. The lake is alkaline. Seasonal variation in the water-level is less than 1 m. Much of the shore comprises rocky or pebble beaches (devoid of vegetation), particularly on the eastern side, with a number of swampy bays in the north and south. The sandy beaches frequented by visitors are mostly on the western shore. Sedges and rushes fringe some parts of the lake and cover many of the small swampy bays. Ceratophyllum demersum and Potamogeton spp. are important submerged aquatics. The area between Lakes Langano and Abijatta is naturally open Acacia woodland and bush, but many of the trees have been cut and much of the land cleared for cultivation. The eastern side of the lake, where the streams enter, retains some trees, especially Ficus sp. and small Sesbania sp. On the southern and south-eastern shores there are dense thickets of Acacia, other spiny bushes, climbers and large Ficus vasta and F. sycomorus trees. The surrounding slopes, within Munessa State Forest, are dominated by Podocarpus falcatus. The lake is much used for recreational activities.
See Box for key species. Falco naumanni and Circus macrourus overwinter in small numbers, with others occurring on spring and autumn passage. Phoenicopterus minor numbers fluctuate unpredictably. Large numbers of waterfowl use the lake, including Pelecanus onocrotalus (regularly 150–200 birds) and Phalocrocorax carbo (small numbers breed on the islands). A number of waders, terns and gulls also frequent the lake. An apparently undescribed Hirundo sp. has been recorded from the cliffs at the southern end of the lake, from where there have also been records of an unidentified Serinus sp. Huge numbers of Motacilla flava and Hirundo rustica pass along the western side of the lake, as do a number of migratory raptors. Other species present around the lake (and in the Munessa State Forest) include a substantial number of the Somali–Masai and Afrotropical Highlands biome species. Aquila verreauxii, Caprimulgus tristigma and Pytilia phoenicoptera have also been recorded.
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
Loss of soil through wind erosion is an increasing problem (preventing regeneration or rehabilitation) as the vegetation around the lake is removed or degraded. This is especially the case between Lakes Langano and Abijatta. Another threat is the development of geothermal power, to the north of the lake, that has the potential to introduce super-hot water into the lake system. Tourism, although not currently a problem, is growing and may have an increasing impact if not managed with environmental considerations in mind. A local organization, FARM Africa, has started a community-based ecotourism project on the eastern shore of the lake, including a tented camp with solar-powered lighting and cooking.