Sustainable harnessing of the surface water resources for Karachi: a geographic review

Abstract

Water resource management has now become the most important challenge in developing countries, especially, in an arid part of the world. In the case of Karachi city, the situation is getting worse day by day due to haphazard urban development, climate change, and an inadequate supply of fresh water. This paper reviews various published research articles and reports regarding Karachi water resources, supply, and demand. The city of over 20 million people has scarce local water resources and imports most of its required water from Indus and Hab Rivers. The city is undersupplied as its rationalized water demand is around 1250 million gallons per day (mgd), while receiving only 650 mgd. Another water source, Hab Dam, which is planned to supply 100 mgd water to the city, is highly uncertain due to intermittent drought conditions in the region. The mega city is facing a water scarcity problem very seriously because of the phenomenal growth of the population and the shortage of a water supply. Subsurface geology and surface topography are favorable to store water in dams and recharge the aquifers. However, over-extraction of water, scarcity of rainfall, sand and gravel excavation, and lack of groundwater recharge infrastructure have depleted the precious resource. There is an urgent need for a comprehensive city development master plan for future growth of the city with clear-cut priorities, policies, and implementation framework. Water sector should holistically be addressed by considering climate change, rapid urbanization, population growth, and perpetual increasing demand from all sectors including industries and agriculture. Besides the development of sustainable policies at the local government level, overall governance, administration, and management need to be improved which may implement the best practices and regulations.