Urban growth in metropolitan Cape Town: Implications for inland and coastal waters

Abstract

Rapid and poorly planned urban growth in Metropolitan Cape Town is subjecting the inland coastal waters in the region to stress. Increasing ex­tractive demands are being made on inland water systems to provide pot­able water. Larger volumes of liquid and solid waste, and increased storm- water runoff are impacting negatively on inland and coastal water quality. Urban sprawl is detracting from the aesthetics of river catchments, and is also impacting adversely on river and stormwater quality. An assessment of future urbanisation in terms of major drainage catchments revealed that most will occur in the False Bay north shore catchment. Priority planning concerns identified are: (1) the lack of fundamental scientific information on coastal ecosystems, particularly those of False Bay and Table Bay; (2) the potentially detrimental (health) impact of bacteria and viruses in urban runoff and from treated wastewater discharge on inland water and coastal recreation nodes; (3) the potentially detrimental impact of nutrients in urban runoff and treated wastewater discharge on in­land and coastal ecosystems; (4) the potentially negative impact of in­creased potable water demand on the Berg, Riviersonde rend, Breede and Palmiet riverine ecosystems; and (5) the opportunity cost (e.g. water un­available for agriculture) of increased abstraction of river and groundwater for urban consumption. The paper con­cludes by emphasising the need for a metropolitan inland and coastal waters management policy to address the lack of coordinated policy and planning within and between local authorities and government departments.