Formulation of strategies for the revitalization of wetlands in sustainable urban design with special reference to Colombo metropolitan region - core area

Abstract

"Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water " (Brian J Hudson, 1996: 117). They have enormous biological resources which can be described as the kidneys of the landscape. Unfortunately this valuable Eco-system has just become unpleasant and even sinister wastelands within an urban context, resulting enormous environmental problems, particularly floods. "Today many societies are learning the foolishness and cost of treating wetlands as a public enemy. Cities that have encroached on wetlands indiscipline manner to bear the tragedy and cost of avoidable flood and other environmental impacts "(Mitchell Breazley, 1993: 6) However, in the recent past, Wetlands have acquired a new dimension mostly due to the hard work done by ecologists and conservationists. An extensive wetland literature at both the technical, scientific has now been made and available on important ecological functions and values of them as a result of the above.In Sri Lanka it is found many of such eco systems in urban areas, eco-systems, which serve utilitarian, recreational, landscape or experimental purposes. Among the wetlands in Sri lanka the low-lying flood plain marshes and related canal system found in CMR are unique. How ever most of these wetlands in CMR as at present merely acting as detention areas which store storm water came through natural drains. In this scenario properly functioning wetland system is an asset and also a 'Green lung' in the city structure of CMR. On the other hand, as the wetlands are poorly treated due to social, political, economic and other reasons, CMR suffering from severe environmental problems particularly in the form of floods, as mentioned earlier. Even though relevant authorities prepare and implement several management approaches and annually spend large sum of monies to maintain and keep wetlands in order, the wetlands continue to pollute and clog resulting several environmental hazards. Accordingly this has become a critical issue to be addressed urgently and also making a strong case for revitalization of the same.