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Home , Lake Eyasi, Lake Kariba, Lake Kivu, Lake Nyos, List of lakes by area, List of lakes by depth

Figure 1-1: A satellite composite image of (Source: NASA) viii Africa’s Introduction

een from space, the Earth appears Africa, with a total area of 30 244 050 the world, many of which are bordered by 1as a largely blue planet, suggesting km2 (11 677 293 square miles), is the two or more countries. Victoria is the S the presence of vast quantities of second largest and second most populous largest of all African lakes and the sec- water. Although this is true, only about two after . It covers approxi- ond largest freshwater body in the world, per cent of the Earth’s water is fresh, with mately 20.3 per cent of the total land area with a surface area of about 68 800 km2 the majority of this small fraction locked on Earth. With over 800 million people, (27 000 square miles). Its extensive sur- up in icebergs and glaciers, or located far it accounts for about one seventh of the face is divided among three countries: the underground beyond our easy reach. Lakes world’s population (Wikipedia 2005). It is northern half to , the southern half appear like blue diamond mosaics in the also the largest of the three great south- to , and part of the northeastern terrestrial mass. As a relative perspective, if ward projections from the main mass of sector to . all the water on Earth could be put into a the Earth’s surface. It is estimated that According to the WORLDLAKE data- 3 four-litre bottle, the readily-available quan- Africa has about 30 000 km (7 197 cubic base, there are 677 lakes in Africa, with tity for use by people would be about one miles) of water in large lakes (Anon 1978; 88 of them listed as principal lakes (see tablespoon, or less than half of one per WCMC n.d.), which is the largest volume Appendix). Although lakes are a source of cent of the total. Nevertheless, even this of any continent. livelihoods in most African societies, they small amount is deemed suffi cient to meet Africa is endowed with hundreds of are also a major source of natural disas- all the present and foreseeable people’s lakes, both natural and artifi cial (Table ters, tropical diseases and pandemics. It is needs – if it were evenly distributed around 1.1). For example, Lake Bosumtwi is a important to note that Africa’s lakes are the world and protected from degradation. natural lake that was formed by a crater also undergoing signifi cant changes due A lake is defi ned as a large body of when a large meteoroid smashed into to a combination of human activities and water, usually , which is sur- the continent. Lake Nasser, on the other climate change, with potentially serious rounded by land. Lakes are usually formed hand, is a or artifi cial lake created implications for people’s livelihoods and when natural depressions or basins in the behind the Aswan in Egypt. Africa is aquatic . land surface become fi lled with water over also home to some of the largest lakes in time. They can range from small ponds to water-bodies stretching hundreds of kilo- Lake Tonga Lake Ichkeul Lake Al Wahda metres and containing vast quantities of water; large lakes are sometimes referred to as ‘inland seas’. Some small seas are also often referred to as lakes (Wikipedia 2005). As defi nitions of what constitutes a lake also vary, the precise number of the Toshka Project world’s lakes is diffi cult to determine. Lake Nasser In contrast to fl owing streams and rivers, lakes provide a means for pooling Lake Djoudj or storing water for varying periods of Lake Manantali time. Lakes are one of our most important Challawa Gorge Reservoir natural resources, especially in the tropics, where they form highly productive biologi- Songor Ch’ew Bahir cal systems. They provide water for con- Lagoon sumption, fi shing, irrigation, power gen- eration, transportation, recreation, and a Lake Kyoga Lake Ntomba variety of other domestic, agricultural and Lake Mai-Ndombe Lake industrial uses (Zinabu 1998). Natural and human made lakes and wetlands provide signifi cant storage of KEY somewhat easily accessible global terrestrial Study Lakes Lake Bagweulu Lake water, which varies seasonally and annually Other Major Lakes Lake according to climate variation and anthro- Cahora Basa Lake Chilwa Lake Alaotra pogenic activities. There are approximately Lake Chivero 50 000 natural lakes and 7 500 human made lakes in the world (Ryanzhin 2004). Despite the publication of several world lakes datasets and databases (Herdendorf Lesotho Highlands Lake Sibaya Reservoir 1982; Birkett, Mason 1995; ILEC 2002; Lake St. Lucia Wetlands International 2002; Lehner, Döll N 2004), most data on limnologically studied 0 500 1000 Kilometres natural and human made lakes are dis- persed over a wide range of literature. Figure 1.1: Distrubution of Africa’s major lakes UNEP/GRID–Sioux Falls 1 The Mankwe Dam in Pilanesberg National Park, South Africa. Unknown/UNEP/MorgueFile

Table 1.1: Africa’s lakes by country Africa, and particularly , has research focusing particularly on Lakes numerous lakes that support very impor- Victoria, Tanganyika and Malawi. However, Country # of Lakes Percentage tant fi sheries —providing a livelihood governmental support for lakes remains Uganda 69 10% to millions of people, and contributing low in many African countries, with little signifi cantly to the food supply. In many of money allocated from national budgets for Kenya 64 9.50% these lakes, however, fi sheries are reach- their conservation or development 59 8.70% ing a state of maturity and unsustainabil- (Petr 2005). Tanzania 49 7.20% ity. The fi sheries of just 11 lakes in the 11 Although Africa’s lakes are limited and 46 6.80% countries of eastern Africa employ close to sensitive resources that call for proper care half a million people, with perhaps three South Africa 37 5.50% and management, they remain among the times as many engaged in secondary activi- most abused of the continent’s natural re- 29 4.30% ties and related services—thus supporting sources. The direct disposal of wastewater Ghana 29 4.30% about four per cent of the ’s entire into lakes continues to have a damaging Morocco 26 3.80% population (Petr 2005). This has also impact on their fragile ecological balances. resulted in transboundary water confl icts, 25 3.70% Human impacts in lake basins and catch- despite the creation of regional initiatives ments also have devastating consequences Egypt 16 2.40% on integrated water management. Trans- for the lakes themselves, including: rapid 16 2.40% boundary freshwater resources will clearly siltation caused by accelerated soil ; Mali 15 2.20% become a source of growing confl ict in irreversible uptake of water and/or salini- Tunisia 15 2.20% Africa without the development of—and sation due to irrigation; eutrophication; adherence to—sound multilateral agree- Zaire 15 2.20% contamination with toxic chemicals and ments for their shared management. mine tailings; and acidifi cation. Effec- Malawi 13 1.90% The degree of resource utilisation tive integrated watershed management Botswana 12 1.80% differs greatly from lake to lake, and ac- requires not only strict soil conservation Gabon 8 1.20% cording to the two main types of fi sheries: measures, but changes in the way that Others 134 <20% demersal/onshore and pelagic/offshore. water moves through the agro-ecosystem. Currently, demersal/onshore resources Total 677 100% In Africa, human factors, in combina- are being more heavily exploited or over- tion with the natural conditions of climate Source: World Lakes Network (2004) exploited. Africa’s large lakes are receiving and geology, may infl uence water quality considerable biological attention through to a large extent. Some African nations do a number of international activities, with

2 not have industries that fl ourish in devel- • The multiplicity of transboundary in meeting competing demands for basic oped countries, and pollutants are not pro- water basins water supplies (World Commission on Wa- duced in such large quantities. However, • Extreme and temporal variability of ter for the 21st Century n.d.). pollution resulting from land-use changes, climate and rainfall Water supplies are undoubtedly one of environmental modifi cation and other • Growing water scarcity the most important resources for Africa’s practices associated with rapid population social, economic and environmental well- • Shrinking of some water bodies increase, have caused or accelerated many being. Currently, about two-thirds of the changes in the continent’s lakes (Zinabu • Desertifi cation rural population and one-quarter of the 1998). The major human threats include: urban population are without safe drink- The main threats to water quality in Af- • The pursuit of inappropriate gover- ing water, and even higher proportions rica include eutrophication, pollution, and nance and institutional arrangements lack proper sanitation. Climate change will the proliferation of invasive aquatic plants in managing national and transnational likely make the situation even worse. The such as the water hyacinth. Industrial water basins greatest impact will continue to be felt by wastes are still discharged without treat- • The depletion of water resources the poor, who have the most limited access ment into rivers and lakes in most African through pollution, environmental deg- to water resources (Watson et al. 1997). countries, posing a major and persistent radation, and deforestation Other threats to Africa’s lakes include: health problem. Recurring droughts are • Poisoning: Mercury poisoning is af- also a major threat to, and cause of, water • Failure to invest adequately in fecting at least three of Africa’s Great shortages (Ottichilo 2003). resource assessment, protection and development Lakes: Turkana, Naivasha and Baringo Africa’s freshwater supply, including (Campbell et al. 2003). its lakes, is threatened by certain natural • Unsustainable fi nancing of investments • Drought: Lake Chad, once one of the phenomena and human factors. Among in water supply and sanitation continent’s largest freshwater bodies, the greatest natural threats are: These threats pose challenges in man- aging the continent’s water resources and has dramatically decreased in size due

A young boy near a waterfall. CARF/UNEP/Flickr.com

3 to climate change and extraction. Once assess the stability of its natural dam monitor changes affecting lakes in their close in surface area to ’s warned of the risk of its potential countries. An integrated approach will , Lake Chad is now a ghost collapse within the next fi ve years, be taken in mapping out the changes in of its former self. According to a study and called for urgent measures to African lakes, including the main causes by University of Wisconsin- Madison prevent it. and effects of human activities. As water researchers, working with NASA’s Earth The Africa Water Vision for 2025 sustains life, the effective management of Observing System programme, the lake (World Commission on Water for the 21st our water resources demands a holistic is now one-twentieth of the size it was Century n.d.) calls for: approach, linking social and economic 35 years ago (NASA 2001). development with the protection of natu- • Strengthening the governance of ral ecosystems. Sustainable management • Killer lakes: In August of 1986 Lake Africa’s water resources Nyos in Cameroon “exploded,” releas- must link land and water uses across entire • Improving national and regional ing up to 1 km3 (0.6 cubic miles) of catchment areas, as well as direct uses of water wisdom lakes themselves, and should include the CO2 and killing about 1 700 people up to 26 km (16 miles) away. A smaller gas • Meeting the most urgent water needs mainstreaming and crosscutting of popula- burst from Lake Monoun in August • Strengthening the fi nancial base for a tion, health and climate changes in evaluat- 1984 killed 37 people. Steps are being sustainable water future ing utilisation and management strategies. undertaken to reduce such risks in the This Atlas vividly illustrates some of The analyses in this publication have been future (Kling 2005). the changes that people and nature have aided by the use of satellite imagery to map out demographic and environmental • Flooding: In addition to drought, lakes wrought on Africa’s lakes – both good and changes within Africa’s lake ecosystems. may fl ood, posing threats to human bad – in recent decades, and presents an The publication intends to provide a clear populations living close by. An example overview analysis of the situation of 24 ma- and practical basis for promoting more is Lake Kyoga (Goulden 2005). jor lakes (see Table 1.2). In doing so, it also effective management and monitoring of • Potential collapse of : The United serves as an early warning of the precarious environmental situation of many of Africa’s Africa’s lakes, for making informed policy Nations team of experts dispatched decisions and encouraging individual ac- on 21 September 2005 to Lake Nyos, lakes, and seeks to inform policymakers on the need to consciously assess and regularly tions to help sustain the livelihoods of the in Cameroon’s Northwest province, to communities that live around them.

Table 1.2 Lakes, and lagoons featured in this Atlas* Name Country Surface area [km2] Maximum depth [m] Alaotra, Lake Madagascar 200 Al Wahda, Lake Morocco 123 Challawa Gorge Reservoirs Nigeria Cahora Basa Reservoirs 2739 157 Chad, Lake Chad/Cameroon/Niger 1540 10.5 Djoudj, Lake Senegal 160 Ichkeul, Lake Tunisia 120 Kariba, Lake / 5400 78 Kivu, Lake Rwanda, Zaire/Congo (DR), Rwanda 2220 480 Lesotho Highlands Reservoirs Lesotho Malawi (Nyasa, Niassa) Malawi, Mozambique, Tanzania 29500 706 Manantali, Lake Mali 200 Nakuru, Lake Kenya 40 2.8 Monoum, Lake Cameroon Nasser, Lake Egypt 5248 130 Nyos, Lake Cameroon 96 Sibaya, Lake South Africa 78 43 Songor Lagoon Ghana St. Lucia, Lake South Africa 300 8 Tana, Lake Ethiopia\Kenya 3600 14 Tanganyika, Lake Tanzania/Zaire/Zambia/ 32000 1471 Burundi, Congo (DR), Tanzania, Zambia Tonga, Lake Algeria Toshka Project, Reservoirs Egypt Victoria, Lake Tanzania/Uganda/Kenya 68800 84

Source: WorldLakes 2004

* See appendix for more statistics.

4 Figure 1.2: Satellite image showing the of Africa. This image vividly shows the major lakes of eastern Africa as they twist down the two arms of the Great in nine countries in East and . The Great Lakes of Africa include some of the largest and most ecologically diverse freshwater systems on the planet. Eight of the 15 lakes in this region are ranked as ‘Great Lakes’ – a testimony to their size and depth. Lake Victoria is ranked as the second-largest freshwater lake in the world, and Lake Tanganyika as one of the deepest. Source: NationMaster.com 2006

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