A Guide to Wetlands in Kenya
What is a Wetland?
Wetlands are perceived as those ecosystems that integrate the characteristics of terrestrial and aquatic environments, that is, water, soil and vegetal profile. The degree to which these properties are combined exhibits spatial, temporal and wetland types. The latter accounts for the broad definitional base contained in the Convention on Wetlands of International Importance, notably of waterfowl habitat, more proper the Ramsar Convention whose overarching aim is to stem the progressive encroachment on and loss of wetlands. The Ramsar Convention describes wetlands as “areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed 6 ms”. Instructively though, this definition does not encompass permanent, deep water bodies and courses, although it includes shallow areas near the shorelines and riverbanks. Kenya acceded to the Ramsar Convention and it came into force in the country on October 5, 1990. Kenya Wildlife Service (KWS) is designated as the convention’s implementing authority and national focal point. Wetlands cover about 6% of the Earth’s surface area. Although the exact extent of Kenya’s wetlands is unknown, owing to the lack of a wetlands inventory, they are estimated to occupy around 3 to 4% of Kenya’s land mass although this can temporarily increase to 6% during the rainy seasons (Kenya Wetlands Forum 2012). Despite their modest geographic extent, the wetlands around the world provide a number of important ecosystem services which are indispensable to humans and biodiversity’s very survival, salubrity, and welfare.
Variations of Wetlands in Kenya
Ramsar classification of wetland types contains three broad categories: inland; marine and coastal; and man-made. These are then sub-divided into 42 types. Owing to Kenya’s diverse climate and topography, it’s home to 6 wetland types: riverine; lacustrine; palustrine; estuarine; marine; and human-made wetlands. Riverine wetlands occur along rivers and streams. They are common along the country’s main watercourses, the most important of these being Athi, Ewaso Ng’iro, Nyando, Yala and Tana Rivers, although the latter is covered in detail under the estuarine category of wetlands. Lacustrine wetlands occur in and around lakes and are predominantly influenced by these water bodies, whether these are fresh or saline. As lakes are situated in topographic depressions, water is the key feature and they typically lack trees, shrub and persistent emergents. Although lacustrine wetlands are common in the Lake Victoria basin and Rift Valley region, they also occur in craters, for instance Lakes Simbi and Sonachi (Crater Lake), Mount Kenya’s Lake Alice, Tyndall, Hut Tarn, and Hanging Tarn.
All of the five locations in the country that have been designated as Wetlands of International Importance (Ramsar Sites) are lakes (Nakuru, Naivasha, Bogoria, Baringo and Elementaita) all part of the Great Rift Valley system, and lacustrine wetlands by nature. Moreover, all these lakes are important bird habitats and are renowned for their large flamingo populations. As such, they are frequently visited by ornithologists, making them an important component of the tourist circuit. While Baringo and Naivasha are freshwater lakes, Nakuru, Bogoria and Elementaita are alkaline. These relatively shallow lakes collectively expand over an area of 1,018 km2. Palustrine wetlands comprise marshes, swamps, bogs and floodplains. As these lack flowing water and are generally speaking non-tidal, a defining characteristic is that they are typified by persistent emergent wetland plants such as Cyeprus papyrus. Many small palustrine wetlands in the country serve as insular habitat islands in the centre of heavily populated areas. Others serve as agricultural land such as the King’wal Swamp in Nandi County and Nyando floodplain in Kisumu County. Estuarine wetlands occur where fresh and salty water mix, to include deltas, tidal-marsh and mangrove swamps.
Kenya’s estuarine wetlands inventory includes those in the Tana River Delta, at Mombasa, Shimo La Tewa, Kilifi, Turtle Bay as well as the islands of Lamu, Pate and Manda. Marine wetlands are those that are exposed to the waves and currents of the open ocean and as such display a high level of salinity typically exceeds 3%. Kenya’s marine wetlands portfolio is consisted of lagoons, shingle beaches, mangroves, rocky shorelines, salt marshes, mudflats, sea beds and coral reefs, with each of these exhibiting unique hydrological and topographical attributes. For example, while the country’s sea grass beds predominantly occur in shallow reef slopes and sandy beaches are associated with coastal areas that are dominated by terrigenous sediment but without fringing reefs, coral reefs occur further seaward, around the Marine Protected Areas (MPAs) such as the Mombasa Marine National Park and Malindi Marine National Park & Reserve. Kenya’s human-made wetlands comprise a number of disparate artificial structures. These include water impoundment for irrigation (such as the Mwea, Ahero and Bunyala irrigation schemes) or hydroelectric power generation with the attendant major dams, principally of the Seven Forks Hydro-Power Project.
Wetlands in Kenya
1. Shompole (Ngare Ng’iro) Swamp
Shompole or Ngare Ng’iro Swamp is found within the Ewaso Ng’iro South River floodplain in the Ngare Ng’iro plain. The river flows through this swamp before eventually draining into Lake Natron. The weather in Shompole is marked by a high ambient temperatures and low, bimodal rainfall. Mean annual rainfall varies from 300 to 800 mm. Although this is an arid/semi arid area, Shompole Swamp, along with the Ewaso Ng’iro South River, provides sufficient water for domestic use and for livestock watering. Its significance is highlighted by the fact that during the dry spell, Shompole Wetland is virtually the only grazing land available for livestock. It’s also home to prolific of faunal and floral species.
2. Lorian Swamp
Ewaso Ng’iro North basin has an estimated area of 213,731 km2, making it the largest of the wetland designated basins. The Ewaso Ng’iro North River, a mid-sized, permanent river, is the most important wetland in this basin. It drains Mount Kenya and the Aberdare in central Kenya and flows eastward to Somalia. The Ewaso Nyiro River runs for over 450 kms before it finally reaches the lofty bed of reeds nearby Habaswein in the southeast corner of Wajir County, simply known as Lorian Swamp. The 151 km2 Lorian Swamp, which means ‘swamp’ in the native Laigop dialect, was first cited by William A. Chanler and Ludwig Von Hohnel in 1898, who detailed it as “of a great extent filled with high reeds.” The lengthy Ewaso Nyiro River drainage, which also includes the Lorian Swamp, is a critical life-line in Garissa County. Little is known of the Lorian Swamp due to the hostile terrain and inaccessibility despite being one of the largest wetlands.
3. Tana River Basin
River Tana is, without question, the longest river in Kenya flowing for over 850 kms with a catchment area of about 95,000 km2, thence draining at the Indian Ocean at the Ungwana Bay in Kipini. It travels over five Counties of Kenya from its source in the Aberdare Mountains, west of Nyeri, with a river basin draining 21% of the Kenya’s land surface and is home to 18% of the country’s population. All along its course, it provides a vital lifeline for both the wildlife and for the people who live nearby Bura and Tana Delta Irrigation Schemes – which draw from River Tana. Further upstream, River Tana Power Project, momentously known as Seven Folk Project, is Kenya’s indispensable hydro-electric source. Moreover, this contributes over 50% of Kenya’s river discharge to the Western Indian Ocean. At its terminus at the Indian Ocean, River Tana discharges on average 4,000 million litres of fresh water every year. In Tana River County, the red muddy river flows parallel to its east border. One of the basin’s salient ecosystems is the Tana Delta at the coast. This biodiversity hot spot is home to a great many endangered species, and it was designated as a Ramsar site in 2012.
4. Athi River Basin
Apart from the Athi River itself, the wetlands in the Athi basin are also linked with the Nairobi River which originates from the Ondiri Swamp, the Mbagathi River which originates from the Ngong Hills, the Kiboko River whose primary catchment is Endoinyo Narok and the Tsavo River, which drains the northern slopes of Mount Kilimanjaro. These rivers supply water to the Athi River which, like the Tana River, empties into the Indian Ocean. The Amboseli sub-basin (an internal drainage basin), situated north of Mount Kilimanjaro, is a significant component of this basin with Lake Amboseli being the main wetland in this subbasin. Although seasonal, it receives a regular water supply from Namanga River, which comes from the Meto Hills. The basin also receives both surface runoff and underground water supply from Mount Kilimanjaro’s melting snow.
The seepage of underground water in the basin has a series of marshes, swamps and springs on the lake’s east shores. In addition, there are seasonal wetlands, such as the Kimana swamp pans, that fill with water during the long wet season.
5. Lake Amboseli
The 20 kms long featureless dusty plain of Lake Amboseli, which sustains only few inches of water in the course of the rainy season, between March to July, is quite an extraordinary component of Amboseli National Park; not least for the remarkable distortion of landforms by the heat haze, which at times makes it difficult to distinguish between the mirage and the actual surface of the water. Amboseli National Park has a tremendous concentration of big game especially around the waterholes frequented by rhinos and elephants. It’s also one of East Africa’s best location for viewing the cheetah. The perfectly flat surface of Lake Amboseli, which provides a nimble and comfortable line of communication in dry weather, becomes completely impassable to vehicles during the rain season.
6. Ondiri Swamp
The papyrus fringed Ondiri Swamp, “a misnomer because it is not a swamp per se but what is known as a peat bog, and Kenya’s largest highland bog”, is found just 1 km from Kikuyu Town. It possesses very unique oddities. Covering about 30-hectares, and the only known quaking bog (a spongy and shaky ground with no foundation) in Kenya, it is foremost a major inlet for Nairobi River and joins other minor streams rising from Kikuyu Escarpment to drain into Athi-Sabaki-Galana River – one of the two major rivers alongside Tana River terminating at Indian Ocean. As with many things swamps, Ondiri is thought to draw much of its water from underground seepages, which explains why it retains reasonable amounts of water even the dryer periods of the year, with little infiltration loss. It is also thought to have a dumbfounding depth of 10 kms. The second deepest wetland zone inside Africa following one in Doula Cameroon. Furthermore, this artless swamp functions as an underground outlet for Lake Naivasha. Ondigi Swamp is a popular leisure oasis and its callers particularly like to hop on the bogs. The little-known Nyakumu Swamp is located 20 kms from Ondiri Swamp.
7. Kingwal Wetland
From Kapsabet it is a 46 kms journey to Eldoret through Mosoriot and Mlango along C39 Kakamega-Kapsabet-Eldoret Road. The drives goes past the graceful farmlands of Nandi interspersed by patches of woodlands, villages and small centres. 8 kms from Kapsabet, at Chepterit, one would be interested in taking a detour via Chepterit-Kapkagaon Road to Kosirai, to explore Kingwal Wetland, which is popular as a breeding ground for the rare Sitatunga antelope. Kingwal is one of only few places in Kenya where the rare semi-aquatic Sitatunga can be sighted in its habitat. Happy in the swamps, this shy antelopes often submerges until only the face is above water when it is frightened. Kingwal Swamp covers about 3 km2, easily toured on foot. The 10 km2 Kingwal Wetland comprises of a system of rivers, streams and springs that are interconnected within the habitat.
8. Yala Wetland
Standing further up one of the many hillocks that from a low ridge around the 175 km2 Yala Swamp Wetland its scale and beauty are wondrous, perhaps even stupefying. From here, the flat cauldron-shaped evergreen sward comprised of patches of bogs, marshes and swamp always makes an impression. A good pair of binoculars will better this experience ten-fold. Yala Swamp which is one of the most important wetlands found within Kenya is set along the northeastern shoreline of Lake Victoria forming the mouth of Rivers Yala and Nzoia. It also harbours three freshwater satellite lakes – Kanyaboli, Namboyo and Sare. The birds are the star here and the rich biosphere of the Yala Swamp is classified as one of Kenya’s Important Birding Area (IBA). Much to the delight of birders, it is almost impossible to keep up with the diverse and fascinating species of birds at Yala estimated to be upwards of 100, that include: endemic species like great snapper, baillor’s crane, papyrus Gonolek, papyrus canary and yellow warbler. Travellers to Yala Swamp Wetland should also look forward to the vistas of the open water of Lake Victoria from sundry vantage points spread out around the wetland, the cultural passages to Swila and Seje, and boating at Lake Kanyaboli.
9. Sio Siteki Swamp
The Lake Victoria North basin associated mainly with Rizers Nzoia and Siteki is the world’s second largest freshwater lake. The Sio Siteki Wetland comprises of interconnected secondary and tertiary wetland sub-systems connected through a system that stretches in areas near the Kenya-Uganda border and draining into Lake Victoria along the Kenya-Uganda boundary. The location of the Sio-Siteko wetland system, along two countries, renders a big challenge in terms of well-defined administrative structures and legislature to guide its management. Midway between Busia and Bumala, near Matayos, is an oddity among Busia’s places of interest. Call it a miraculous anomaly! And there is a startled feeling of enchantment about the Sio Siteki Swamp which mysteriously turned into a lake less than five years ago, yet, it harbors a prolific variety of birdlife and a superb floral diversity. By harnessing attributes of a mature tropical resource – floral and faunal – it has inspired the touring mojo of many residents of Busia who frequent Sio Siteki Swamp to bear witness to the marvel. A significant portion of its landscape consists of the papyrus-fringed headwater which opens up to a picturesque 1 km2 lake. While plenty of tropical lakes have been formed by the actions of rivers or by earth movement and tectonic activity, experts are yet to give a conclusive explanation for the Sio Siteki Lake. It is thought that the lake was formed from the dynamics of surface and underground seepage. Sio Siteki Swamp and Lake is located in Munongo Village within the Matayos Sub-county.
10. Nyando (Kusa) Wetland
The Lake Victoria South basin covers the area around Lake Victoria that sits between the Yala River, past Migori River and up to the border with Tanzania. The main wetlands of the basin are associated with the Migori, Nyando and Sondu Miriu Rivers. All these rivers originate in the Mau Forest Complex and all eventually drain into Lake Victoria. The Nyando (Kusa) Swamp forms at the mouth of the Nyando River where it enters the Winam (or Kavirondo) Gulf of Lake Victoria. It’s generally covered with thick papyrus (Cyperus papyrus) beds. The Nyando Wetland occurs on the Kano Plains at the mouth of Nyando River and along the shores of Lake Victoria. The Kano Plains occupy two thirds of the lower half of the Nyando River catchment. Over the plains, its vast micro-relief consists of broad swellings and troughs, with the winding channels of Nyando River crossing the lower areas. At the mouth of Nyando River, it is contiguous with many papyrus dominated lakeshore wetlands forming the second largest wetland (14,400ha) on the Kenyan side of Lake Victoria. During the dry season, base flows in the rivers and streams are considerably reduced, resulting in the drying up of large sections of the wetlands. Nyando Wetland is diverse and rich with flora and fauna including the Kisumu Bird Sanctuary, and Okana Wetland.
11. Rift Valley Basin Wetlands
The Rift Valley is a 60 km-wide internal drainage basin. The main wetlands in the region are; Lake Magadi, Lake Nakuru, Lake Naivasha, Lake Baringo, Lake Turkana and Turkwel River. Apart from the freshwater Lake Naivasha and Lake Baringo, all the basin’s lakes are alkaline. Major rivers in this basin include the Mara, Ewaso Ng’iro and Kerio which all originate in the Mau Forest Complex, as well as the Turkwel River which drains Mount Elgon. Owing to its ecological significance, uniqueness and rich biodiversity, Lake Naivasha was designated as a Ramsar Site in 1995 making it the second Ramsar Site in Kenya after Lake Nakuru. Some of the threats to Lake Naivasha include weighty sedimentation, clearing of natural vegetation for agriculture especially horticulture, and over-harvesting of the fringing papyrus along the main inflow rivers, the Malewa and Gilgil as these traditionally shield the water body from excess sediment inflow.
12. The Mara River Basin
The Mara River Basin is shared between Kenya (65%) and Tanzania (35%) and forms part of the larger Nile Basin that is shared by ten African countries. The source of the river is Napuiyapui Swamp in the Mau Forest Complex in Kenya. It then meanders through the internationally renowned Maasai Mara-Serengeti ecosystem before its outfall in Lake Victoria at Musoma in Tanzania. The waters of the Amala and the Nyangores Rivers which are the perennial tributaries of the Mara are complemented by the Talek, Engare Ngito and Sand Rivers. There are only a few permanent wetlands in the Maasai Mara, and most are seasonal, occurring where water is trapped at the surface by the reserve’s black cotton soil, or where underground streams emerge. The significance of the Mara River is underscored by the fact that it is regarded as the lifeblood of the vast Maasai Mara-Serengeti ecosystem that covers a catchment area of 25 000 km2. Mara ecosystem is also home to a prolific concentration of non-migratory predators such as the African lion, leopard, cheetah and the spotted hyena and herbivores most notably the elephant, rhino, Maasai giraffe, gazelles, a variety of primates.