Powai lake

POWAI LAKE

Powai Lake (named after Framaji Kavasji Powai Estate) is an
artificial lake, situated in the northern suburb of Mumbai, in the
Powai valley, where a Powai village with cluster of huts existed.
The 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.[1] Another famous institution, the National
Institute of Industrial Engineering (NITIE) is also located close to
the lake. Housing complexes and plush hotels are developed all
around the lake periphery. Population around the lake has thus
substantially increased over the years.
When it was built, the lake had a water spread area of about
2.1 square kilometres (520 acres) and the depth varied from
about 3 metres (9.8 ft) (at the periphery) to 12 metres (39 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
The Powai Lake has gone through many stages of water quality
for drinking water has been declared unfit to drink. The Powai

Follow me on www.webbieguru.blogspot.com

Lake has gone through many stages of water quality
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 the 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.[4] 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, a Parsi merchant, after
whom the lake was named when it was built in 1891.
The drinking water supply objective of the lake 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. Realising the gravity of the environmental
pollution of the lake, the MSAA has revised its constitution,
to actively care for, clean, develop, maintain, and beautify the
Environment at Powai Lake.
MSAA is now involved with a) removal of water Hyacinth
infestation, b) supporting research with Fisheries Dept.for
conservation of the Indian Mahaseer, c) Water quality analysis
d) and augmenting security.

ACCESS
The lake is about 40 kilometres (25 mi) from Mumbai by road
and is approached via King's Circle, Sion, and Kurla or through
Santa Cruz and Andheri.[6] Kanjurmarg on the central main line
of the Mumbai Suburban Railway is the nearest railway station
to the lake.

HYDROLOGY AND WATER QUALITY


It is reported that the average rainfall at Powai is about 2,540
centimetres (1,000 in), 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.[2] It supplied two million gallons of water to
Bombay (now Mumbai) when it was built. Following the
construction of the Tansa dam and creation of the reservoir, in
1892, Powai waters were used for irrigation.[7] 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).[8] 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.

LAKE REJUVENATION
Appreciating the problem of silting, growth of water hyacinth,
weed, and eutrophication of the lake, the IIT Bombay's Class of
1980 launched a "Revitalization of Powai Lake” with the
objective of restoring the lake to its original pristine and
sustainable form by adopting Eco-friendly designs and materials
for the restoration works.
Some of the tasks proposed to be undertaken with the funds
donated by IIT, Bombay included:
• Removing water hyacinth and weeds from the lake in parts
nearest to the campus
• Starting a publicity and an awareness program in the area
• Building embankments, walkways and pathways to the lake
• Constructing a large gazebo for an evening (or morning or
afternoon) by the lake

• Planting trees, and creating a garden
• Installing docks, deploying boats and canoes
• Allocating funds for annual maintenance
The project was proposed to be professionally managed with a
project manager working under directives of IIT Bombay with
an “Oversight Committee“ to monitor objectives set for the
restoration work.
In 1995, the National Lake Conservation Plan (NLCP) of the
Ministry of Environment and Forests (MoE&F),Government of
India, reviewed the condition of Powai Lake and included the
Lake in its list of ten major lakes in the country for revival and
improvements. The restoration/revival programme, fully
funded by the NLCP, was launched in April 2002, and
implemented by Bombay Municipal Corporation (BMC) now
called Brihanmumbai Municipal Corporation (BMC), the
Government of Maharashtra and as a result the status of the
lake has undergone a major shift from the hypertrophic
condition to mesotrophic condition by adopting a novel
technique of aeration and bioremediation. This has resulted in
the lake being used for fishing and recreational purposes.

Temperature


The water temperature varies with the atmospheric
temperature i.e. being maximum during summer i.e 35ºC and
minimum during winter i.e 22ºC.

pH
As per pH value is concerned, it was found that throughout the
month slightly lower values during monsoon season and slightly
higher values during winter, but throughout the mo nth it
remained slightly alkaline.

Dissolved Oxygen
Dissolved Oxygen content in Powai Lake was found to be very
low throughout the month. DO content ranged from 0.2 to 4.4
mg/l indicating the anaerobic conditions in the lake water. This
indicates low rate of primary production in aquatic ecosystem
of lake. Minimum amount required for optimum fish
population may be as high as 5 to 8 mg/L. The oxygen depleting
substances reduce the available DO. According to Trivedy and
Goel (1 986) reported that low oxygen concentrations are
associated with heavy contamination by organic matter.

Nitrogen
During the investigation nitrogen content was found to be
varied from april to September.High level of nitrogen in lake
can be due to lack of oxygen at the bottom of the lake.


Conductivity
Conductivity was higher in summer months due to the
increased concen tration of salts which would have been
caused due to evaporation during that season. The conductivity
ranged from 360 to 810 Mmhos/cm.

Chloride
The Chloride concentrations of Powai Lake during the study
were found to be below the permissible limit. Chlorides are
present in water as Sodium chloride, Magnesium chloride and
Calcium chloride.Although they are not harmful as such, their
concentration over 250 ppm imparts a particular taste to the
water rendering the water unacceptable for drinking purposes.
Existence of unusually high concentration of chloride in lake
indicates pollutants from domestic sewage and industrial
effluents and thus leads to eutrophication. In addition to that
salinity was also calculated which too shows increase in during
summer season and decrease in monsoon season.

MAJOR CAUSES OF DETERIORATION OF LAKE
o Uncontrolled development and unauthorized
quarrying activities in the catchments area.
o Ingress of untreated sewage from the residential
areas.


o Dumping of garbage and other waste materials in the
lake.
o Washing of clothes, vehicles, open defecation etc. On
the lakeshore.

DESILTING PROJECT
The Lake's water depth is reported to have reduced to as little
as 0.33 metres (1.1 ft) at some locations, on account of the
large inflow of sewage, domestic waste water and silt from
surrounding residential and industrial areas.
Brihanmumbai Municipal Corporation (BMC) has therefore
plans to desilt the Powai Lake at a cost of US $9 million.

FAUNA


Large number of crocodiles on the lake side have been sighted
on the shores of the lake and also reported by fishermen and
officials of IIT, Powai.

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,, 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.

FLORA
Balsam bushes, in their full bloom, in pink-purple color are seen
around the lake periphery, like a carpet.
Powai Lake is an artificial lake, situated in the northern suburb
of Mumbai. The lake was created in 1891 by constructing dam
between two hillocks across Mithi River. Catchment area of the
lake is about 600 hectors and water spread area at full supply
level is 220 hectors. The lake water is used for non-potable
purposes i.e. gardening and industrial use.


In recent times, 40% of the lake has disappeared. The lake has
deteriorated due to accelerated growth of residential,
commercial and industrial area around the lake. The untreated
disposal of sewage and garbage from nearby residential and
slum colonies have affected the quality of the water.
Dissolved Oxygen level at the bottom of lake has gone low as
0.71 mg/ltr, and at the top it is 4.11mg/Ltr. The catchment of
the lake has also been affected badly due to unplanned
quarrying activities.
Appreciating the problem of silting, growth of water hyacinth,
weed, and eutrophication of the lake, the IIT Bombay's Class of


1980 launched a "Revitalization of Powai Lake” with the
objective of restoring the lake to its original pristine and
sustainable form by adopting Eco-friendly designs and materials
for the restoration works. In 1995, the National Lake
Conservation Plan (NLCP) of the Ministry of Environment and
Forests (MoE&F), reviewed the condition of Powai Lake and
included the lake in its list of ten major lakes in the country for
revival and improvements. The restoration/revival programme,
fully funded by the NLCP, was launched in April 2002, and
implemented by Bombay Municipal Corporation (BMC) now
called Brihanmumbai Municipal Corporation (BMC).

Adjoining Attractions
 Mahakali Caves


The Mahakali caves built about 2000 years ago has several
rock-cut figures of the Buddha and Buddhist legends. These
caves are situated in Udayagiri hills near the Kondivita village.
 Kanheri caves
The Kanheri Caves are located north of Borivli on the western
outskirts of Mumbai, within the Sanjay Gandhi National Park's
green forests.
 Sanjay Gandhi National Park wildlife park
Sanjay Gandhi National Park, earlier called Krishnagiri National
Park covers an area of 104 sq. km and is the largest park in the
world, located within city limits.

CONCLUSION
 Powai lake having catchment area of 6.61 Sq. Kms &
lake surface area of 2.10 Sq. Kms is improved within a
period of 12 months. This is the 1st successful project
executed in India using “Aeration and Bio-
remediation Technique”.
 The status of lake was transformed from
Hypertrophic condition to Mesotrophic condition.
 Use of the aeration and bioremediation technique
was effective for improving the quality of lake water
to the accepted standard for water bodies being used
for fishing and recreational purposes.

 Though the installation cost of equipment, power and
monitoring the water quality is high, the cost of
maintenance is relatively low.


Powai lake

Recomendados

Recomendados

Más contenido relacionado

La actualidad más candente

La actualidad más candente (20)

Destacado

Destacado (10)

Similar a Powai lake

Similar a Powai lake (20)

Último

Último (20)

Powai lake