2. • What is it?
• Why do we need it?
• Why do we need to study about it?
• Water is the single most important
abiotic component of an
• Water is needed to sustain life.
• On earth water is regenerated
through the water cycle
4. WATER CYCLE
• Lakes are a source of drinking water
• It acts as a rainwater buffer
6. Total number of lakes
• There are about 540 major lakes in
• Maharashtra has about 63 major lakes
• There are 7 major lakes in and around
• They are Tansa Lake, Vihar Lake, Tulsi
Lake, Vaitarana, Bhatsa, Modak Sagar
and Powai lake.
7. • Of these only Powai lake doesn’t supply
Mumbai with potable water.
8. POWAI LAKE
•Mumbai’s first artificial lake.
•Named after Framaji Kavasji.
•Created in 1891 by constructing
dam between two hillocks across
a tributary of Mithi River.
•Area at full supply level is 220
•It was planned as an antiwater
• Located in the Powai valley, where a Powai village
• Indian Institute of Technology, Bombay and The
National Institute of Industrial
Engineering, some of the premier educational
institutions in India are on the periphery of this
• Plush and expensive Housing complexes and
plush hotels are developed all around the lake.
When it was built, the lake had a water spread area of
about 2.1 square kilometres (520 acres)
the depth varied from about 3 metres (9.8 ft) (at the
periphery) to 12 metres (39 ft) at its deepest.
12. • It is reported that the average rainfall at Powai is
about 2,540 cms.
• The lake overflows for about for sixty days each
year. The overflow from the lake flows into the
• Silt studies conducted in 1995 estimates that 4500
lakh cubic metres of silt has been deposited in the
lake since its construction.
• Powai lake supplied two million gallons of water to
Bombay (now Mumbai! )when it was built.
14. DECREASE IN AREA
In recent times, 40% of the
lake has disappeared.
• Accelerated growth of
Quarrying activity in the
catchment area nts around
15. Water quality deterioration
• Untreated disposal of
sewage and garbage from
nearby residential and
slum colonies have affected
the quality of the water.
• Washing cattle also
deteriorates the water
16. • Water hyacinth and weeds from the lake use
up all the dissolved oxygen.
• Dissolved Oxygen level of lake has gone low
as 0.71 mg/ltr.
Silt studies conducted in 1995 estimates that 4500 lakh
cubic metres of silt has been deposited in the lake
since its construction.
The Lake's depth is reported to have reduced to as
little as 1.1 feet at some locations.
Eutrophication is the ecosystem
response to the addition of artificial or
natural substances, such
as nitrates and phosphates,through
fertilizers or sewage, to an aquatic
20. SEPTIC SEWAGE PUMPING SYSTEM
• Uses septic pumps
• Filters the drainage left
out from factories
• 24 hrs of constant observation
• Avoids malpractices and damage to public
• Prevents litering around lake
22. Education and encouragement
• Educating about water issues and hazards
• Encourage people to participate
• Creates awareness among public and
• Bioremediation is the use of micro-
organism metabolism to remove
• Widely used and effctive
• Provides employment
• Planting of saplings nearby lake
• Creating landscaped gardens and walkways
around the lake.
• It prevents soil errosion to a great extent
• Desilting will increase the quantity of water.
• Removing water hyacinth and weeds
26. PREVENT RAMPANT CONSTRUCTION
• Prevent construction of dhobi ghats and
toilets in the areas near the lake.
• Stop construction in the catchment areas.
27. This solution and remedy are possible only if
there is inner motivation in an individual.
Ethics plays here vital role
People should understand what is right and
wrong and function accordingly.
Lakes are a part of our ecosystem and habitat to
various flora and fauna.
So these lakes as well as other water resources
should be protected at all costs.