African Water Development Report 2006 - United Nations Economic ...

African Water Development Report 2006The African Ecosystem at Risk (WWDR) formulated according to World Ecosystem atRisk (WWDR)Main threats to ecosystems from human activities(UNESCO/WWDR, 2003)• Population and consumption growth.• Infrastructure development (dams, urban growth, highways).• Land conversion (deforestation, agriculture, urban growth).• Over-harvesting and over-exploitation (over-fishing, wastefulirrigation).• Release of pollutants (human waste, agricultural and industrialchemicals).• Introduction of exotic species (replacing and overwhelmingindigenous species).River pollution• Most African rivers running through cities are badly polluted dueto untreated domestic and industrial effluents• Rapid urbanization in Lagos increased solid waste generationsixfold to about 3.7 million tonnes a year in 1990, plus anotherhalf a million tonnes of largely untreated industrial waste because90 per cent of the industries in Nigeria lack pollution controlfacilities• About 3 million people across the region die annually as a resultof water-related diseases. 72 per cent of all reported choleracases in the world in 1998 were in Africa (UNEP GEO3).• The concentration of industries in or near cities is also a majorsource of environmental pollution and resource depletion.• In 1994, the spill of toxic chemicals from a pulp and papercompany into the Usuthu river in Swaziland killed many fish(Mavimbela 1995).• In Mozambique, more than 126 factories in and around Maputodischarge their waste directly into the environment (Couto 1995).• In Tanzania, textile mills are reported to release dyes, bleachingagents, alkalis and starch directly into Msimbazi Creek in Dar esSalaam (Bwathondi, Nkotagu and Mkuula 1991).Impacts of waterways diversion and fragmentation• Most of Africa’s largest rivers are severely fragmented by dams,diversions and canals, leading to the degradation of ecosystems.• Africa has at least 1,272 large dams with 39 situated in SouthAfrica, 213 in Zimbabwe and 107 in Algeria (UNISDR, 2004).• The Bakolori Dam in northwestern Nigeria on the DokotoRiver reduced its average flood levels by 50%, leading to a 53%decrease of cropped area WWF (2004)• Between 500,000 and 800,000 people no longer have accessto productive floodplains that provided much of their livelihooddue to the Manantali Dam on the Senegal River WWF (2004)• About 25 per cent of the land is now subject to water erosionand about 22 per cent to wind erosion, leading to increasedsiltation of rivers and dams (UNEP GEO3).• In the Sudan, for example, the total capacity of the Roseieresreservoir, which generates about 80 per cent of the country’selectricity, has fallen by 40 per cent in the past 30 years as a resultof silting from the Blue Nile (UNEP GEO3).Wetlands loss:• Studies show that more than 600 lakes in Africa have shrunk dramaticallyover the past decades, drained by deforestation, pollution andfarming (David Stauth, 2005).• A study by University of Wisconsin-Madison researchers, workingwith NASA’s Earth Observing System program show that lake Chad isnow 1/20th of the size it was 35 years ago due to increasing humanneed for water, mostly through massive irrigation projects and alsosignificant decline in rainfall since the early 1960’s. (NASA, 2001, afrolNews, 2001).• In 20 years, countries such as the Niger lost more than 80 per centof their freshwater wetlands (David Stauth, 2005).Biodiversity loss:• At the African level, many species are highly threatened: over 2000animal species and close to 2000 plant species being endangered(UNISDR, 2004).• Lake Victoria, the second largest lake in the world, was declared bythe Global Nature Fund (GNF) as the “Threatened Lake 2005“. Ofabout 500 fish species 50 years ago, some 200 species are estimatedto be on the verge of extinction.• Over 45 per cent of Africa is affected by desertification, 55 per centof which is at high or very high risk (UNEP GEO3)• Madagascar has the most Critically Endangered and Endangeredprimates and has lost 90% of its original vegetation.• The number of Kafue lechwe, a type of antelope endemic to theKafue Flats, has decreased to a third of its originally estimated 1970population of 100,000 and elephants, rhinoceroses, giraffes and wilddogs have disappeared from the area entirely due to change of floodpatterns as a result of two dams on the Kafue river (WWF, 2004).• Central Africa had lost about half of its wildlife habitats by 1986.During 1980-1995, the number of extinct plants in Southern Africa increasedfrom 39 to 58. More than 700 vertebrate species, and around1 000 species of trees are threatened with extinction (UNEP GEO3).• Government statistics show that Nigeria loses 350,000 hectares ofarable land per year. In the north of the country, 10 states have alreadybeen affected and each year, the desert advances another 600 metresfurther south (Anne Isabelle Leclercq, 2005).Coastal and Marine ecosystems• Africa’s rich coastal and marine areas are under threat from pollution,an estimated 38 per cent of coastal ecosystems, such as mangroveswamps and coral reefs, are under threat from developments like portsand the growth of coastal settlements and their sewage discharges.(UNEP – GPA, 2001)• The supply of phosphate and silicate nutrients to the coastal NileDelta was reduced to 4% and 18% respectively after the Aswan HighDam was built, leading to significant reduction in productivity of coastalfisheries WWF (2004)• The waters of the Western Indian Ocean are major sea routes foran estimated 470 million tonnes of oil every year. This comes with ahigh risk of disastrous oil spills. Several oil spills have affected Africanpenguins and other marine life (UNEP GEO3).158