Hussainsagar Lake and Catchment Area Improvement Project
From Wikipedia, the free encyclopedia
Hussainsagar Lake and Catchment Area Improvement Project is a project led by Hyderabad Metropolitan Development Authority to improve the quality of Hussain Sagar Lake (pictured) in Hyderabad, India.
Hussain Sagar Lake was built in 1562 during the reign of the Qutb Shahi dynasty at Golkonda. It is an artificial lake built on a tributary of River Musi.[1][2] The lake water was utilised for irrigation and drinking water needs from 1884 until 1930. The total catchment area of the lake is 240 square kilometres (93 sq mi). Through four main feeder nullahs – Picket Nalla, Kukatpally Nalla, Banjara Nalla and Balkapur Nalla – water from the catchment area reaches the lake.[3]
Urbanisation and rapid industrialisation developed Hyderabad into a metropolis. Several heavy industries were also set up in the city.[4]
Since 1930, the lake has gradually started receiving sewage and industrial effluents through the feeder nullahs. The Picket Nalla discharges mostly domestic sewage throughout the year into the lake from the north-eastern side. Similarly the Banjara Nalla (from north-western side) and Balkapur Nalla (from western side) discharge mostly domestic sewage into the lake. The Kukatpally Nalla discharges a mix of domestic sewage and industrial effluents into the lake from the northern side. This practice of discharging municipal sewage, industry effluents and storm-water from over 240 square kilometres increased the content of organic matter, nitrogen and phosphorus. This suspended organic matter, rich in nutrients, caused eutrophication that allowed growth of algal blooms and water hyacinth.[3]
Over the years, the twin cities have seen idol immersion during the festivals of Ganesh Chaturthi and Dasara. As a part of this religious ritual, idols of the worshipped deities along with flowers, leaves and other material are immersed into water bodies. Similarly, during Muharram every year, colourfully painted Tazia are immersed in large numbers in the lake by the regional Islamic community.[5] Besides adding silt, studies indicate that these immersions have increased the pollution levels in the lake. A 2009 survey shows that the chemical oxygen demand and biochemical oxygen demand in the water body increased drastically after these festivals.[6]