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

African Water Development Report 2006metal, microbial contamination, toxic organiccompounds, salinization, acidification, suspendedparticles and temperature.The algae eutrophication that is polluting severalwater bodies in Africa is caused by increasednutrient levels from poor agricultural practicesand discharge of untreated wastes. Groundwaterresources are becoming polluted by three maincauses: (a) leaching of pollutants from agriculture,industry and untreated sewage, (b) salinizationthrough saltwater intrusion and irrigationwater seepage, and (c) natural hydrogeochemicalpollution. There are very few studies on groundwaterquality in Africa and, currently, there isno comprehensive programme of groundwaterquality monitoring on the continent. Industrialpollution, effluent discharge and other forms ofpollution, are contaminating freshwater lakes,wetlands and dams leading to various forms ofwater body degradation, including quality reductionand biodiversity loss. These seriously impairthe ability of freshwater systems to filter and purifywater. Changes in lake water condition, as ameasure of lake water quality, from the 1960s tothe 1990s, show that conditions in 40 per centof the lakes in Africa have worsened while 5 percent improved (UNESCO and Bergham Books2003).African countries have undertaken a wide rangeof measures to prevent and control water quality,including:(a) Integrated land and water management;(b) Improvement of freshwater storage, treatmentand distribution;(c) Control of watershed degradation throughmeasures such as site protection, environmentalregulations and public awareness;(d) Urban sanitation interventions, includingwaste treatment;(e) Establishment of potable water qualitystandards and effluent controls;(f ) Abstraction management;(g) Improving the institutional framework forwater supply management, including deepeningparticipation through communitywater and sanitation schemes and water usersassociations;(h) Ratification of relevant regional and transboundarywater management conventions;and(i) Removal of aquatic weeds.The importance of a particular water quality issuedepends on the context: the definition of waterquality is not objective but is socially determined,depending on the use of the water. Hence, theestablishment, monitoring and enforcement ofcompliance with standards for water quality, waterabstraction and watershed use are crucial inpreventing and controlling water pollution. Enforcingcompliance with planning and regulatoryprovisions often requires the twin approachof using incentives and deterrents. The formerincludes economic incentives, such as pollutioncharging, based on the polluter pays principle,and discharge permits, but their effect is notmuch felt in Africa, largely due to informationdeficiency. To improve results, the approach toachieving compliance should strike an appropriatebalance between enforcing compliance withregulations and adopting participation-orientedapproaches based on self-consent. Nonetheless,one important lesson is that key institutionalfactors may be in place for consultation and cooperativeapproaches to help ensure successfulwater quality management, but regulatory bodiesmust continue to enforce regulations (WorldBank 2003).Dam Failure RisksThere are at least 1,272 large dams in Africa,mainly for irrigation and water supply, followedby hydropower generation. South Africa has thehighest number of dams (539) followed by Zimbabwe(213) and Algeria (107). Overall, Africahas 2.4 per cent of the world’s large reservoirs,including dams. Most of the major river basinsin Africa have been dammed, resulting in significantbackflooding. However, reservoir develop-244