Saturday, March 7, 2009

Powai Lake

View-Powai lake
Powai Lake (named after Framaji Kavasji Powai Estate) is an artificial lake, situated in the northern suburb of MumbaiThe city suburb called Powai, shares its name with the lake. Indian Institute of Technology, Bombay, one of the premier institutions of science and technology in India is located to the east of the lake. Another famous institution, the National Institute of Industrial Engineering (NITIE) is also located close to the lake. Posh housing complexes like Hiranandani and plush hotels are developed all around the lake periphery. Population around the lake has thus substantially increased over the years.
Powai Lake is located downstream of the Vihar lake on the Mithi river.
When it was built, the lake had a water spread area of about 2.1 km² (370 acres) and the depth varied from about 3 m (10 ft) (at the periphery) to 12 m (40 ft) at its deepest.
The Powai Lake has gone through many stages of water quality degradation. The lake water which used to supply to Mumbai for drinking water has been declared unfit to drink. The Lake still remains a tourist attraction.
History
A stream tributary of Mithi river, which served the Powai village's water supply needs, was dammed in 1891, during the British period, initially to augment water supply to then Bombay city (now called Mumbai), by constructing two dams of 10 m height each to store the rain waters flowing from the lower slopes of the Western Ghats and streams from the eastern and northeastern slopes of hills. It was planned as an antiwater famine measure, to the southeast of Vihar Lake (a much larger lake) also for water supply to Mumbai city.
Before the lake was built by the British, in the year 1799 A.D., the estate where the lake is now located was leased on a yearly rent to Dr. Scott and after his death in 1816 A.D., the government took control of the estate in 1826 A.D., and leased it once again to one Mr. Framaji Kavasji Powai, a Parsi merchant, after whom the lake was named when it was built in 1891.
The objective of the suply of potable water was abandoned in the early 1990s, in view of poor quality of the water stored, caused due to pollution, water hyacinth and weeds, untreated sewage and large silt deposit. The lake was, therefore, leased out to the Western India Fishing Association, a quasi government organisation who used it for both fish culture and angling. Later, the Bombay Presidency Angling Association was formed in 1936 and later in 1955, under the Societies Registration Act 1860, it was registered as “The Maharashtra State Angling Association” (MSAA) and the lake is now under their control.
Access
The lake is about 40 km (25 miles) from Chhatrapati Shivaji Terminus by road and is approached via King's Circle, Sion and Kurla or through Santacruz and Andheri. Kanjurrmarg on the central main line of the Mumbai Suburban Railways is the nearest railway station to the lake.
Hydrology and water quality
It is reported that the average rainfall at Powai is about 2540 mm (85 inches), and the lake overflows for about for sixty days each year. The overflow from the lake flows into the Mithi River. Silt studies conducted in 1995 estimates that 4500 lakh cubic metres of silt has been deposited in the lake since its construction. It supplied two million gallons of water to Bombay (now Mumbai) when it was built. Following the constrcution of the Tansa dam, in 1892, Powai waters were used for irrigation. The lake drains a catchment of 6.61 km² (part of the Powai-Kanheri hill ranges which also drain into the adjoining Vihar Lake and Tulsi Lake). The dam, built in stone masonry has a height varying from 3 m to 6m with top level of the dam kept at E.L. 58.5 m (with Town hall datum). Government of Maharashtra reports that due to eutrophication of the lake water from untreated sewage and garbage from nearby residential and slum colonies, the lake water is unfit for drinking water use. Hence, the lake is now used for recreation, gardening, cattle washing and fishing. The water of the lake is also supplied to Aarey colony and L&T for non domestic uses. Dissolved Oxygen (DO) level at the bottom of the lake is reported to be 0.71 mg/litre and at surface 4.11 mg/litre, average value of pH is 7.2 and COD is 42.70 mg/litre on the surface and 119 mg/litre at the bottom of the lake.
Fauna
Large number of crocodiles on the lake side have been sighted on the shores of the lake. White throated kingfisher, small blue kingfisher, spot-billed duck, spotted dove, a few purple moorhens, purple rumped sunbirds, bronze winged and phaesant tailed jacanas, ashy prinias, brahmany kite, Red vented, red whiskered and white browed bulbuls, cormorants, lesser whistling ducks, grey, purple and pond herons, little, intermediate and large egrets, little grebbe, perigrine falcon, greater coucal, rose ringed and Alexindrine parakits, eurasian marsh harrier(possibly winter visitor), wooly necked stork (winter visitor) hopooe & whiskered terns. butterflies, honey bees, bumble bees and beetles have also been sighted.

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