The impact of socio-economic and human behavioural factors on the water of the Fontein Spruit catchment: a water management model study in a developing community

[摘要] English: A world water crisis has been predicted as early as 1977 and since then, waterprofessionals call this coming crisis to the attention of the world community atvarious conferences, summits and congresses. Recent assessments conductedfor the United Nations and for the World Commission on Water indicated thatalmost half a billion people face water shortages in 29 countries and by 2025,almost two-thirds of the people are forecast to experience some form of waterstress. Although this global water crisis tends to be viewed as a water quantityproblem, water quality is increasingly being acknowledged as an importantfactor in water scarcity. In many developing countries water quality has becomethe principal limiting factor to water availability. The water quality situation indeveloping countries is highly variable reflecting social, economic and physicalfactors, state of development as well as climatic and geographical factors.In recent years several studies have been done in South Africa to determine thequantitative and qualitative characteristics of urban runoff and their impact onreceiving waters. These studies suggest that there was a large difference in thetype of pollutants that were observed in the receiving waters and that the majorfactor affecting the type of pollution is the type of development that thecatchment is undergoing. The studies conducted on the high-density informalsettlements imply that any form of urban development that includes shacksand/or informal houses will have a detrimental effect on the quality of urbanrunoff. Low-cost, high-density type urbanisation, with its informal housing andshack areas, is an inescapable part of South Africa and will continue to play amajor role in this country for many years to come. In recent years, South Africahas experienced a massive increase in urbanisation, a large proportion of whichtakes the form of high-density, informal settlements that developed aroundexisting metropolitan areas. Based on current patterns of growth, the extent ofthis form of urbanisation is predicted to treble within 20 years. This rapid growthof urban areas in South Africa has been accompanied by increased quantitiesof contaminated urban runoff and this, in turn, has accelerated the degradationof streams, rivers, lakes and estuaries. Urban runoff acts as an efficienttransport mechanism for bacteria, viruses, nutrients, organic substances, heavymetals and other pollutants. Alone or in combination, these substances causewater quality problems, pose potentially serious risks to human- andenvironmental health through contact recreation and through the use ofuntreated water. Therefore, it is vitally important that the scientific andengineering society continue to study these urban catchments and to developnew and innovative ways of dealing with the problems associated with urbanrunoff.The study area provided a unique opportunity for the investigation,implementation and evaluation of an integrated water quality managementprogramme, as it is a typical example of a community with rapid, largelyuncontrolled, growth of low-cost, high-density housing developments. Theresearch project was primarily aimed to gain a better understanding of the majorcauses of pollution in the study area, and once the principle contributing factorshad been identified and investigated, a Water Quality Management Plan wasdeveloped. The research project was based on the assumption that waterquality problems arising from developing communities can be managed usingan integrated approach to ensure that the receiving water environmentalobjectives can be met on a sustainable basis and that the managementpractices and interventions to deal with pollution problems from developingcommunities can be sustained by addressing the socio-economic and humanbehavioural factors contributing to the problems. The Water QualityManagement Plan is therefore an integrated plan addressing the managementof water quality in the community in the study area, and also permits theextrapolation of the results to catchments with similar land use and humanactivities, locally as well as regionally.

[发布机构] University of the Free State