Environmentally-sensitive river management : assessment and mitigation of impacts on urban rivers
type: CreativeWork
description: Urban development and engineering works have resulted in the majority of rivers that drain urban areas being severely degraded, both ecologically and in terms of their potential amenity value. This dissertation explores the reasons for this "spiral of degradation" and it describes the ecological and social impacts on rivers caused by urban development, channelisation and canalisation. It then suggests possible measures to mitigate the impacts at the levels of the catchment, floodplain and river channel. The present cycle of degradation of urban rivers in the Cape Metropolitan Area (and elsewhere) can be halted. In addition, where degradation has already occurred, mitigation and rehabilitation are possible and could restore some of the lost conservation and ecological values, as well as the potential amenity, recreation and education functions. Early colonisation of Cape Town by Europeans inflicted severe impacts on the rivers surrounding and passing through the city. These included: catchment degradation, water abstraction, the disposal of unpurified sewage and industrial effluents, removal of riparian forests, clearing of instream vegetation and the draining of wetlands. During the 20111 century, many urban rivers have been "improved" by straightening or confining within rectangular concrete-lined canals in order to protect urban development in flood-prone areas. The unquestioning faith in technology during this period and the attitude that human ingenuity could "improve nature" are now regarded by the scientific community, together with some local and regional authorities and informed members of the public, as mistakes that resulted in ecological and environmental degradation. These technical solutions merely treated the symptoms of the problem without recognising, let alone attempting to treat, the causes, that is poor catchment and floodplain management. However, there is still a public demand for canalisation of the remaining "natural" rivers in the greater Cap…
abstract: Urban development and engineering works have resulted in the majority of rivers that drain urban areas being severely degraded, both ecologically and in terms of their potential amenity value. This dissertation explores the reasons for this "spiral of degradation" and it describes the ecological and social impacts on rivers caused by urban development, channelisation and canalisation. It then suggests possible measures to mitigate the impacts at the levels of the catchment, floodplain and river channel. The present cycle of degradation of urban rivers in the Cape Metropolitan Area (and elsewhere) can be halted. In addition, where degradation has already occurred, mitigation and rehabilitation are possible and could restore some of the lost conservation and ecological values, as well as the potential amenity, recreation and education functions. Early colonisation of Cape Town by Europeans inflicted severe impacts on the rivers surrounding and passing through the city. These included: catchment degradation, water abstraction, the disposal of unpurified sewage and industrial effluents, removal of riparian forests, clearing of instream vegetation and the draining of wetlands. During the 20111 century, many urban rivers have been "improved" by straightening or confining within rectangular concrete-lined canals in order to protect urban development in flood-prone areas. The unquestioning faith in technology during this period and the attitude that human ingenuity could "improve nature" are now regarded by the scientific community, together with some local and regional authorities and informed members of the public, as mistakes that resulted in ecological and environmental degradation. These technical solutions merely treated the symptoms of the problem without recognising, let alone attempting to treat, the causes, that is poor catchment and floodplain management. However, there is still a public demand for canalisation of the remaining "natural" rivers in the greater Cap…
author: Luger, Michael Karl
language: eng
date published: 1998
date modified: 2026-07-24T01:34:13Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Environmental and Geographical Science

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/13886