By Sean Avery
In recent months, the international conservation agenda has been topped and dominated by wildlife crime, ivory, rhino horn and the illegal trade in live animals and animal parts. This is a welcome focus for a very unwelcome business. But there are other pressing conservation issues that would benefit from similar international focus and concern. One, which the EAWLS has long been concerned about, is the future of Lake Turkana, the Jade Sea of legend, and the impact of Ethiopia's Omo Basin development plans might have on the world's largest desert lake. In this article, hydrologist Sean Avery lays out the threats and the opportunities posed by one of the biggest water-related development plans of modern times.
On November 23, 2013, Kenya and Ethiopia were to sign an agreement to "develop a joint plan for sustainably managing the environment and resources of Lake Turkana and its river basins for the benefit of both people and the environment". This did not take place, and at the time of writing, the reasons were not known. The Lake Turkana basin covers over 130,000 square kilometres, shared in near equal proportions between Kenya and Ethiopia, but also encroaching into South Sudan near the Ilemi triangle, and extending into Uganda in the west near Mount Elgon.
In 1996, Ethiopia presented its master plan for developing the Omo Basin, an area populated today by about 14 million people.
The Omo river discharges 14 per cent of Ethiopia's annual runoff, an enormous resource almost matching Kenya's entire surface water runoff. The highlands of the upper basin enjoy plentiful rainfall, whereas the lower basin's lowlands approaching the lake are semi-arid.
In 2006, Ethiopia started building the massive 243 metre high Gibe III hydropower dam on the Omo River, some 600 kilometres from the lake.
In 2009, scientists claimed that there would be radical reductions in inflow to Lake Turkana due to reservoir leakages underground. They forecast the lake dropping 10-12 metres with aquatic ecosystems declining. Also in 2009, the African Development Bank (AFDB) commissioned a hydrological study of the impacts on Lake Turkana, the first study of its kind on the lake itself.
This AFDB study modelled changes to hydrological cycles and modelled huge drops in lake levels resulting from large- scale irrigation abstractions. In 2011, Ethiopia commenced transferring 445,500 hectares of land in the Lower Omo from its traditional owners to commercial farmers from outside the area. Over 135,000 hectares of land were degazetted from the Omo and Mago National Parks, and from the Tama Wildlife Reserve, for conversion to sugar plantations.
The planned Lower Omo development's land area is almost three times Kenya's current irrigated area. The projects are mired in controversy. Neither feasibility studies nor Environmental and Social impact Assessments (ESIAs) have been released for the irrigation schemes. The Gibe III downstream ESIA was an afterthought done three years after dam construction started, and it did not investigate impacts on Lake Turkana, and did not consult Kenyan stakeholders.
Lake Turkana was not within the study area of the Omo Basin Master Plan. International donors considered impacts on the lake to be of little consequence, and that these could be compensated through sharing benefits such as hydropower.
The World Bank however cold-shouldered the Gibe III project, but only because the direct sourcing of the contractor was not acceptable under the Bank's procurement procedures. Human rights organisations have decried the manner in which the irrigation projects are being implemented, claiming that this is a land-grab, with the local people unwillingly evicted from their traditional lands by the authorities, without adequate compensation, and to the accompaniment of physical abuses.
Leading members of the international community are being accused of turning a "blind-eye", perhaps mindful of international vested interest and not wishing to upset a strategic partner? Interestingly, the Omo Basin's own Master Plan in 1996 drew attention to the lessons of people being displaced by government-sponsored commercial development, and warned strongly against repetition of past mistakes.
The Lake Turkana National Parks comprise Sibiloi National Park, Central Island, and South Island, listed together as a World Heritage Site, and believed threatened by the consequences of the Gibe III dam construction. The World Heritage Committee has twice received recommendations from its experts that the Lake Turkana National Parks should be included on the World Heritage endangered list, and each recommendation has been set aside by the Committee.
The Omo is the reason Lake Turkana exists, providing 90% of the lake's freshwater input. Lake Turkana is uniquely the world's largest desert lake. Located within Kenya's most arid area, this is Kenya's largest lake, its semi-saline waters supporting Africa's highest salinity fisheries, its ecology derived from the lake's former fluvial connection to the Nile basin. 6,500 years ago, Turkana was a freshwater lake five times its present size, its water level nearly 100 metres higher than today, its waters spilling into the Nile Basin about 150 km north- west of the present lakeshore. This lake is an extraordinary example of climate change. As the region became increasingly arid, the lake level dropped and the basin closed with no outlet, thereafter becoming progressively more saline. The lake's contemporary lowest levels occurred in the 1940s, 1950s and 1988, dry periods that occurred throughout Kenya. The lake's level today is higher than those levels.
About one million people in Kenya live in the former Turkana, Samburu and Marsabit districts that border Lake Turkana. These northern areas have long been neglected, with very little government investment. The area is insecure, with constant livestock rustling, and the people are amongst the nation's poorest. They traditionally depended on pastoralism, a livelihood very well suited to these arid lands, but undermined by rising population challenges, insecurity, land fragmentation, restrictions in mobility, and absence of adequate governmental support for the livestock marketing sector. Alternative livelihoods have developed, including crop production and fishing, but to a limited extent.
In some places today, up to 75 per cent of the food input is external food aid. In the 40 years since 1969, the population of Turkana district increased four-fold. By the year 2050, the national population will be treble the 2010 population. The area's wildlife is already threatened and in serious decline. Weapons proliferate throughout, thus adding to wildlife vulnerability. Wildlife is virtually non-existent along the lake's western shore, and there is human encroachment into protected areas on the islands and the north-eastern protected area.
A recent field trip reported hardly any crocodiles, with crocodile nests witnessed being raided, and with animals (crocodiles and turtles) unfortunately taking baited fishhooks or entangling in fishing nets, and then drowning. This depressing scenario of declining wildlife will be further compromised if the escalating poverty and human needs are not dealt with. There are now real prospects of major infrastructure investment in the area, thanks to government policy stimulated by the excitement surrounding oil finds in the region. A major transport corridor is planned through the area from Lamu to South Sudan.
These developments could be to the benefit of local people and wildlife, but if improperly managed could instead further impoverish local people and increase pressure on diminishing wildlife. The oil exploration is ongoing, and production is a long way off. In addition, UNESCO recently announced a deep palaeo freshwater lake beneath the Turkana rangelands west of the lake towards Karamoja. This lake is said to be the size of Lake Turkana, complementing four other deep-water aquifers announced earlier. The UNESCO team claims that these resources may have major implications and potential impact in terms of national and regional development. It is even suggested the resource might serve the nation for 70 years in a crisis.
Although there are real opportunities with the water, there is danger in raising unrealistic expectations. This water resource is dependent on the "weak aquifer recharge" characteristic of low rainfall areas. The quality of the deep-water reservoir is uncertain, and pumping costs will be prohibitive. Crop development in arid and semi arid lands requires huge water quantities, and the water sources will take time and investment to prove and develop. Lake Turkana enjoys year-round sunshine and warm waters. The prevailing southeasterly winds drive surface currents in the upper layers, and cause reverse currents in the lower layers. The water column is well mixed, turbid, and well oxygenated. The surface current transports zooplankton to concentrate on the NW shores, leading to unusual concentrations of small pelagic fish and their predators.
The lake is popularly known as the Jade Sea, its colouration attributable to its blue-green algae, the lake's dominant phytoplankton. In spite of inadequately regulated commercial fishing, including encroachment into protected areas, large handsome Nile Perch still flourish.
The most profound seasonal changes in the lake arise during the annual flooding, which peaks in the period August to October. The principal flood source is the Omo river, which provides around 90 per cent of the lake inflow. The upstream seasonal inundation of offstream areas, and the runoff therefrom, releases valuable organic matter and nutrients, which are carried into the lake by floods. Nitrogen, one of the two most important factors limiting fisheries production (the other being light), is also transported into the lake.
The floods also stimulate the migration of spawning fish into the Omo itself. Within the main lake, fish breeding tends to be greatest during floods. The sediment-rich waters extend south right through the central sector of the lake, diluting the lake water and lowering the salinity levels in northern parts in particular. The sediment plume reduces visibility and fish tend to move to the lake surface and to the shore, and the reduced light penetration affects production of organisms that depend on photosynthesis. The influx of nutrients during the flood season initiates changes in the algal population, and the margins of the lake inundate.
Floodplain fisheries such as Lake Turkana's are reportedly Africa's most productive. Studies have shown that productivity increases with instability, that lake level changes promote interaction between aquatic and terrestrial systems, and that annual fluctuations in lake level are very much more significant than absolute lake levels. More....