EFFECT OF URBANIZATION ON LAKES IN BANGALORE

1. LAKES

A lake is a terrain feature, a body of liquid on the surface of a world that is
localized to the bottom of basin and moves slowly if it moves at all. . On Earth, a body of water is considered a lake when it is inland, not part of the ocean, is larger and deeper than a pond, and is fed by a river.

There are a number of natural processes that can form lakes. A recent tectonic uplift of a mountain range can create bowl-shaped depressions that accumulate water and form lakes. The advance and retreat of glaciers can scrape depressions in the surface where water accumulates.

Lakes have numerous features in addition to lake type, such as drainage basin (also known as catchment area), inflow and outflow, nutrient content, dissolved oxygen, pollutants, pH, and sedimentation.The composition of the lake bed has a significant impact on the flora and fauna found within the lake's environs by contributing to the amounts and the types of nutrients available.

2. LAKES IN INDIA

There is no unique or rigid classification. It depends on the context and the classifier. The commonly perceived classifications are the following:

· Geographical classification like Himalayan, Peninsular, Coastal etc.

· Liminological Classification like Fresh Water, Brackish Water etc

· Functional classification like Irrigation, Water Supply, Hydropower etc.

· Water quality classification

· Management classification.
For the present review, the last classification under the following broad categories is relevant:
· Urban Lakes
· Non Urban Lakes
· Estuarine Lakes
· Ephemeral Lakes

However for the present review we are concerned about Urban Lakes.

3. URBAN LAKES

Urban lakes, sources of water supplies for irrigation, drinking, industries, etc all over the country without exception, are in varying degrees of environmental degradation. Disappearance of lakes is also majorly seen in countries like India. The reasons being,

• Population Explosion
• Urbanization
• Pollutants flowing into lakes from point and non point sources
• Diversion of rivers feeding the lakes
• Discharge of untreated wastes into lakes
• Competition for using lakes for irrigation, hydropower, etc

The water quality of urban lakes in cities like Bangalore has deteriorated so much as to cause serious threat to humans, animals, plants and in turn eco-system. There has been quantum reduction in the number of lakes as well.

4. LAKES OF BANGALORE

Bangalore is located in Karnataka, in the heart of the Deccan Plateau at an average elevation of 920m.The topology is flat except for a central ridge. Though there are no major rivers, Vrishabavathy and its tributary Arkavathy flow across the city carrying Bangalore’s much of the sewage. Bangalore has a handful of lakes to fulfill the water requirements of the city.

Bangalore has been synonymous with its salubrious climate, due to its position on the Deccan Plateaus as well as its extensive greenery and lakes. Lakes, which have been an inherent part of the ecosystem, also have traditionally served the function of meeting water requirements of the populace, be it for drinking, household uses like washing, for agriculture, fishing and also for religious and cultural purposes. Apart from these functions, which involve direct use of the lake water, lakes are also known to recharge ground water, channelise water flow to prevent water logging and flooding. These water bodies are also host to a wide variety of flora and fauna, especially birds.
Apart from these uses lakes in Bangalore also provide employment.
Agriculture: Water from the lakes are utilized for agriculture. Water is accessed either directly by sourcing water from the lake through canals built for this purpose or through tapping groundwater through bore wells replenished by the lakes.
Fishing: Lakes in Bangalore have been sources of fish to fishermen and therefore a source of livelihood. Many fishermen depend on these lakes as a source of livelihood.

Dhobis/Washer men: Many lakes in Bangalore are the home to 'Dhobi gaths', where dhobis wash clothes and dry them for commercial and livelihood purposes.

“Water water everywhere neither a drop to drink”. The history book says there were 159 water bodies spread in an area of 2003 ha in 1973, that number declined to 147 (1582 ha) in 1992, which further declined to 107 (1083 ha) in 2002, and finally there are only 93 water bodies (both small and medium size) with an area of 918 ha in the Greater Bangalore region in 2007.
To name a few are,
1. Ulsoor Lake
2. Hesargatta Lake
3. Yediyur Lake
4. Puttenahalli Lake
5. Sankey Tank
6. Madiwala Lake
7. Hebbal Lake
8. Varthur Lake
9. Dasarahalli Lake
10. Lalbagh lake
Experts say “Disappearance of water bodies and a sharp decline in the number of water bodies in Bangalore is mainly due to intense urbanization and urban sprawl”.


5. URBANIZATION IN BANGALORE

Bangalore is India's third most populous city and fifth most populous urban agglomeration. Today, as a large and growing metropolis, Bangalore is home to some of the most well-recognized colleges and research institutions in India. Numerous public sectors, heavy industries, software companies, aerospace, telecommunications, and defence organizations are located in the city. Bangalore is known as the Silicon Valley of India because of its preeminent position as the nation's leading IT employer and exporter. A demographically diverse city, Bangalore is a major economic hub and the fastest growing major metropolis in India.

Because of the unprecedented economic and demographic growth of the city, the population has increased from 1.7 billion in 1971 to 6 billions. This demographic explosion put a huge pressure on real estate. The extension of residential areas on drained lakes has sped up with rapid urbanization.

6. URBANIZATION AND LAKES

In recent years many lakes of Bangalore have been lost in the process of various anthropogenic activities and population pressures leading to unplanned urbanization and expansion. Many lakes have been encroached due to their valuation resulting in drastic shrinkage of water bodies in the city. In fact, in the name of development many lakes have been already put to alternative use. For example bus stands, stadiums, layouts etc. 14% surrounded by slums and 72% show loss of catchment area.

The possible effects of Urbanization are:
6.1 Urbanization leading to encroachment
6.2 Urbanization lead to the privatization of some lakes
6.3 Unplanned urbanization leading to pollution
6.4 Urbanization leading to enhanced Temperature


6.1 Urbanization Leading To Encroachment

In the name of development to fulfill the aspiring needs of the populace, the great lakes of Bangalore are converted into residential areas,stadiums,bus stand, etc. Few such are
Shoolay lake Football stadium
Akkithimmanhalli lake* Hockey stadium
Sampangi lake Sports stadium
Dharmanbudhi lake Bus stand
Challaghatta lake Golf Course
Koramangala lake Residential layout
Nagashettihalli lake Space department
Kadugondanahalli lake Ambedkar Medical College
Domlur lake BDA layout
Millers lake* Residential layout
Subhashnagar lake* Residential layout
Kurubarahalli lake* Residential layout
Kodihalli lake* Residential layout
Sinivaigalu lake* Residential layout
Marenahalli lake Residential layout
Shivanahalli lake Playground, Bus stand
Bangalore city Bus Stand, once Dharmambudhi Tank
The KGA Golf Course stands on what was once the Challaghatta Tank
The Koramangala Tank is today a Sports Complex

6.2 Urbanization Lead to the Privatization of Some Lakes

Formed in July 2002, the LDA is a registered society, an autonomous body for conserving natural and man-made lakes in Karnataka. The CEO of LDA Mr. CS Vedant clarifies “The LDA does not have adequate staff to manage the lakes. Also, it is government policy not to create too many permanent jobs, as it would increase its expenditure. Hence, we have to find other means to get things done. The leases are one such way.”
Therefore the LDA which failed to cope up with the rapid urbanization in the city leased out few lakes for private organizations.The main problems faced as on date due to this are,
Lumbini Gardens, the leasee of Nagawara Lake, is a real estate group while the East India Hotels group is in the hospitality industry. These private operators chosen have no expertise in lake management at all. Their incompetence in lake conservation is already on display.
At Hebbal Lake, the dredging and removal of vegetation has permanently destroyed the wildlife habitat — a fact that is confirmed by the Forest Department in their June 2008 status report.


6.3 Unplanned Urbanization Leading To Pollution

The potable water in lakes has the following limitations. When the parameters of water exceed these limitations, the water is said to be polluted.E. coli count in 100ml of any sample should be zero.
The emerging realities have put enormous pressure on the government bodies resulting in the overlap of functions with regard to the management of lakes. Improper planning even after rapid urbanization has led to the broken sewerage in the city. This has resulted in the pollution of water making it non-potable.
Encroachment hinders bed treatment of the drains, especially desilting and maintenance. Encroachers flush in all their wastes into the drains too which has increased levels of heavy metals and pH of water. This is creating a grave situation in the city.

Few such lakes affected by pollution are,

A.BELLANDUR LAKE
Due to urbanization in 1990s,there was breakage of chains of tanks feeding the lake. The breakage in chains, unchecked industrial, residential as well as commercial development, resulted in insufficient rainwater reaching the tank and excess untreated sewerage and effluents laden water flow to the tank. This further led to a decrease in aquatic life, which affected the livelihoods of the fishing community.
A view of Bellandur Lake

B. VARTHUR LAKE
A case study by a team of Professors of IISC say the main pollutant in the lake is sewage water. Varthur lake also receives overflowing water from nearby Bellandur lake, which is also contaminated. “Though there are sewage treatment plants near Koramangala and Marathalli Ring Road, their capacity is limited. These plants can treat just five million litres of water everyday while the flow is more than 80 million litres per day, making Varthur lake one of the most polluted in the city.

C. HEBBAL LAKE
The catchment area of the lake was found to be 3750ha and this area includes the residential areas of Yeshwanthpur, Mathikere, Bharat Electronics Limited and colonies.
In 1974 the lake area was 77.95 ha and in 1998 it was 57.75 ha.
Sewage inflow into the lake has altered the chemistry and biology of the lake. Most measured physico-chemical properties of the waters of the lake exceed the acceptable standards for sewage effluent discharge set by the Indian Standards Institute (Indian Standards: 2490, 1982).

D. BYRAMANGLA LAKE
In the case of Byramangala lake, domestic effluents from unsewered areas like Nagarbhavi, Nayandahalli, Malathalli, Jyana Jyothinagar and Kengeri satellite town enter the Vrishabavathi valley and finally enter the Byramangala tank without treatment.
Regarding the water in this lake, the LDA has declared “not suitable for continuous application to land. We cannot do much in the issue as the lake is almost 100 per cent polluted.’’

6.4 Urbanization Leading To Enhanced Temperature

Increase in built up areas and decrease in water bodies has enhanced the city’s temperature. Analysis shows a variation from 23.09°C (dense urban), 22.4°C (open ground) to 22.14°C (mixed urban), and 19.57°C (water bodies) indicating the enhanced temperatures in urbanized regions.
Water bodies-Light Blue

7. RECENT LAKE DISASTERS IN THE CITY

A. MALLATHALLI LAKE
The recent death of over a lakh fish in Malathahalli lake has sent shock waves across the city about the quality of fish and the condition of the city's lakes.
To fulfill the growing demand for fishes, the fishermen here were told to use a chemical 'Nualgi’.This biotech product increased the fishes but resulted in less DO content. Our own study revealed that the Do content was just 2.5-2.8 which is unsuitable for the survival of fishes. More than a lakh fishes died on April 18th, 2009.
Mallathalli Lake with dead fish

B. PUTTENAHALLI LAKE
Encroachments of primary valley of Puttenahalli lake’s raja kaluve will flood Bangalore south areas soon, says a recent survey report.
A BBMP report says there about 61 illegal constructions that have come up in this valley blocking the waters including slum dwellers off JP Nagar.
Similar situations are faced by other valleys such as Sarakki, Vrishabhavathy, Koramangla, Hebbal and Chalagatta.
A considerable reduction in the levels of ground water table is also seen in these areas.

8. MANAGEMENT OF LAKES

Failure to deal with water as a finite resource is leading to the unnecessary destruction of lakes and marshes that provide us with water. This failure in turn is threatening all options for the survival and security of plants, animals, humans, etc. There is an urgent need for:
Restoring and conserving the actual source of water - the water cycle and the natural ecosystems that support it - are the basis for sustainable water management
Reducing the environmental degradation that is preventing us from reaching goals of good public health, food security, and better livelihoods world-wide
Improving the human quality of life that can be achieved in ways while maintaining and enhancing environmental quality
Reducing greenhouse gases to avoid the dangerous effects of climate change is an integral part of protecting freshwater resources and ecosystem.

Finally “Management of Lakes in Bangalore has been a vexed function at best”!
· Lake Development Authority (LDA) established, by Government of Karnataka in 2002.
· Expert Committee formed to study conditions of lake in Bangalore city.
· The expert committee observed that urban lakes are subjected to encroachment and pollution.
· Government Accepted the Commissions report.
· Committee constituted under the Ministry of Urban Development to Plan and Restore the lakes in Bangalore.
· LDA, BBMP, BDA, KFD and other Urban Local Bodies have been involved in Restoration of lakes.
· Government of India has accepted to fund (35% of project cost) restoration of lakes under Urban Renewal Mission programme.
· Balance funds will be met from State and ULB funds.