Wetland constitutes important features of the landscape and subjected to constant change due to urbanisation and in some cases has led to disappearance. The impact on wetlands may be grouped in to five main categories: loss of wetland area, changes in water quality, changes to water regime, overexploitation of wetland products and introductions of endangered or alien species.

Wetlands are facing problems due to major proportion of the population in the catchment area, urbanization and industrialization; and various human activities, which has accounted for the over exploitation and leads to degradation of wetlands.

Wetlands are threatened by excessive loading of silt and nutrients from various sources(point and non-point sources)due to removal of vegetation cover in the cacthment area. Vast areas of wetlands have been encroached for various purposes such as for agricultural purposes, for settlements etc., due to rapid urbanization. These threats are resulted inshrinkage of area. Weed infestation and colonization by water hyacinth causes further degradation of most of the wetland ecosystem.

Effluent from industries, uncontrolled use of fertilizers in the agricultural lands, discharge of domestic wastes and sewerage from human settlements, all contribute to the water quality deterioration to these systems. Wetland waters are diverted for farming, public water supply, hydroelectricity and navigation, which can change its water regime.

Apart from these quality and quantity declinations,it has also decreased the Biological diversity of flora and fauna, migratory birds and also the productivity of the system. Simultaneously several thousand species are now endangered and many other sustainable species, products like fish, timber, medicinal plants, water transport and water supply are over exploited.