LAKE RESTORATION, ISSUES & APPLICATION – THE CASE OF

Rajshekhar Rao Asst. professor M.S. Ramaiah Institute of Technology Bangalore INTRODUCTION

Associated Values of Lakes and their importance

Lakes are the lungs of natural ecosystems and perform several functions. Urban Lakes are however, only a subset of all fresh water bodies, i.e., Reservoirs, Lakes, Ponds, Tanks; etc. The lakes have inherent quality of storing and maintainingggp it for a much larger period than other wetlands. In recent years, there has been increasing concern over the continuing degradation of world's wetlands, particularly rivers and lakes. Lakes sustain all life and perform useful functions in the maintenance of ecological balance.

Interfacing between land and water systems, they are highly productive and biologically rich ecosystems, and are also the most endangered. It is part of India’s national policy to conserve the existing lakes and plan and devise Environment Management plans.

Efforts to conserve these fragile areas and develop them to promote eco -tourism should be undertaken to make aware and sensitive towards environment and protection of our natural resources. Study area - Bangalore Wetlands of Bangalore occupy about 4.8% of the geographical area (640 sq k)km) cover ing both urban and non-urban areas. Baagaoeasngalore has many man- Figure 1: Study Area –Greater Bangaloremade wetlands In Bangalore the lakes were built for various hydrological purposes and mainly to serve the needs of irrigate agriculture. There were 262 lakes (in 1960) within the Green b e lt area of the city, which has fallen to 81 at present . Figure 2: Map showing lakes in Bangalore Lakes in Bangalore are threatened due to

Industrialization

Urbanization and unplanned growth Criteria for Selection of Lake

Bellandur Lake is the largest in Bangalore city, being 3km in length and 2.75km in Width. It is one of the largest man-made lakes in Southeast Asia, located about 20 km from the city tdthSthtowards the South-EtfBEast of Bangal ore cit ithihity which is extreme ly important ecological zone.

Bellandur lake Historically, Bellandur Lake used to to the downstream 25,000 acres of agricultural fields. BlldBellandur LkLake functioned as the kidney of the city. The lake was home to a wide variety of fauna and attracted many migratory birds .

The l a ke a lso prov ide d drinking water to half the cityypp's population.

In the past lake was a major fish trading Present Condition of Bellandur lake

3km in length and 2 .75km inWidth overall catchments area is 110.94 sq.miles The water storing capacity of Bellandur lake is 17. 66 m illion cu bic fee t. Lake polluted due to

• Discharggge of sewage and other wastewater • Dumping of solid wastes into the storm water drains pollute the lake. • The lake contains raw sewage, • Industrial effluents and Domestic garbage. • Does not have proper sewerage System. Methodology : primary, secondary and public opinion surveys personal observations site visits and visual surveys were conducted in order to get data related to various aspects and understand the existing conditions. Studies were basically done at two levels- the Catchments Level and the lake Level- to identify the impacts of different natural and human activities on the lake eco-system. Aspects at the Catchments levels are. physiograpy, climate, land use, drainage, demography, socio-economic status, transportation network, infrastructure, and location of industries. Aspects at the lake level are biodiversity, water quality, land use, settlement pattern, socio-economic status, activities in lake, facilities and amenities, and commercial activities. In addition to this, tourism related data has also been analyzed to understand the eco- tourism prospects Figure 3: Existing land use map of Bellandur lake region Major problems and issues confronting Bellandur lake region: The threats to the BlldBellandur lklake reg ion Eco-system are ppyartly due to biotic pressure from the environment and mainly due to human induced or natural changes in the zone ofif infl uence. The issues/threats can be broadly summarized as below: Figure 4: issues and causes of Bellandur lake region Table 1: Major issues & Causes of Bellandur Lake Sl Causal Factors impacts Resultant effect . n o 1 Cu tting of vegettitation Increase insoil erosion LkLakes becomes Decrease in shallow& transpiration increase in water Increase in storm water spread Increase in flow sedimentation 2 IdIndust tiries situat ed It addsonto OiOrganic EtEutrophi hitication around the lake release load their effluent in to the B.O.D decreases lake 3 Intensive agriculture It increase the nutrients Profuse growth of around the lake using & pollutants organic the weeds & fertilizers & pesticides. matters inside the lake water hyacinth Environmental Management plan

The Environmental Management pan incorporates in the broad land-use plan identification, preservation and protection of the environmentally fragile areas, resource areas, ecological areas, cultural, historical and religious sites, source of pollution, and the environmental hot spots.

Proposals are given for environmental quality improvement by restoration, relocation and rehabilitation of certain activities. Provision of adequate green areas, recreational areas and open areas ensure that environmentally sustainable tourism is established.

Lastly, various strategies and guide lines and policies have been formulated for environmentally relevant sectors such as Industries, transportation, waste treatment, and tourism. Analysis: The analysis is done to understand the various environmental, social and economic problems on the basis of several criteria such as severity, extent and importance. Also the positive and negative impacts of all the different activities undertaken in the lklake are ana lyze d The Land use in the catchment is critically ittThdlimportant. The developmen t activities in the catchment area like veggggetation cutting, housing, development activities, construction of road etc, which increase the erosion rate. Any man made factors affect directly or indirectly affect the quantity and qualit y o f l a ke water. So it is essential to stop any such activities in the lake The Land use around bellandur la To maintain the existing water quality the iden tificati on of hydrological sensitive area are important.so hydrological analysis is carried out. It is observed that the water quality has been reddduced reaching the bellandur lake basin due to various development activity in the catchment Figure 5: hydrologically sensitive area of Bellandur lake catchment area of the lake. Eco sensitive Zones of Bellandur lake Catchment :

The lake catchment has been assessed for the three basic resources which are land i.e. slope, Vegetation, and Hydrology. These factors have assigned value depending upon their criticality, by the superimposition of these parameters; it’s able to demarcate zones within the catchment as ecologically sensitive zones.

The entire catchment has been subdivided in to four ecologically sensitive zones and the treatment of each zone hence varies accordingly. Figure 6: Map showing Ecosensitive zones of Bellandur Lake at Catchments Zone 1 : The outer zone is the Buffer zone of undisturbed vegetation buffered with trees & thick shrubs.

Zone 2 : Agriculture zone, where farmers have been and would continue growing crops based on appropriate and sustainable farming principles.

Zone 3 : Interface zone, the limits of which zone are determined based on the existence of marshes, ponds and etc on the simple rule that restricts farming on areas adjacent to water courses up to a width equal to at least the width of the stream.

Zone 4 : consist of the body of water and its associated vegetation ,which are to be left intact as habitat for wild life, particularly waterfowl and migratory birds. Bellandur lake- proposal

Ecological Critical factors Proposals Environmental benefits Zone Zone 1 Erosion susceptible Afforestation to be done using Improvement in the Hydrological Zone recycled water can be treated as quality of water controls bffbuffer eihither wihith forest, fifruitorchdhard sediment entry. QliQuality & declared as green zone. Provide of water entering in to 200mts. Of undisturbed vegetation tank ensured. buffer with high grass percentage than of shbhrubs & trees. Zone 2 Vegetation Zone, Erosion Preservation of agriculture field .No Dependency on lake susceptible, and development zone around the lake No ensures its maintenance. hyygdrological zone industrial activity. Forms continuous green space, check the speed of runoff. Natural edge supports natural vegetation. Zone 3 Erosion susceptible, No development zone around the lake Forms green space. vegetation zone No industrial activity Check the speed of run hydrological zone off, forms green belt around the lake. Zone 4 Erosion susceptible, 100 mts to 150mts. No construction Potential wetland habitat vegetation zone zone allowed. area hydrological zone Figure 7: Proposed Land use Map of Bellandur lake Guidelines & proposal for Bellandur Lake

The recommendations deal with framing regional policies, guidelines and management tools for the various stake holders. The government should undertake integrated planning and conservation measures in consu lta tion w ith lan dscape arc hitec ts, planners and local people while the developers, operators and suppliers should res pect and follow plannin g restrictions , standard and codes. A Comprehensive Plan be prepared to study with regard to their present status, sustainable use, management and conservation and to formulate strategies for their short term & long term management.

The proposed land use map of (see Figure 7)of Bellandur lake deals with Guide lines at regional level which includes Riparian zone management, Management of surface water bodies & Management of recreational area surrounding the lake. Guide lines at Lake Catchment level are as follows Afforestation : To Protect and enhance the existing forest cover and establish new forest cover on suitable areas so that rainfall pattern is not altered and the region receives the maximum precipitation which can be stored as ground water and is made available throughout the year for various uses within the reg ion. Riparian zone management: To establish and protect the rippgarian zone along the banks of the water bodies and the hydrological channels to act as a buffer between the agricultural lands and the lake.

Section through the lake and Riparian zone Management of Agricultural Zone: To promote a ecologically viable cropping pattern and irrigation methods wherein the area under the cultivation of a particular crop should be based on ecological parameters and in the long run should not degrade the land and the quality of water. MtfUbdIdtilManagement of Urban areas and Industrial zone: No new Industry should be allowed to come up in ecologically sensitive areas and in fertile land. The sewage and sullage from the catchment should be stopped at a point, treated up to acceptable standards and only then be allowed to enter the lake. No new construction to be allowed unless a proper sewage treatment plant is installed. LdLand use w hihhldblldhldblhich should be allowed should be low dens ity development with large open spaces. For each settlement coming under the catchment area percentage allocation for different landuses to support the basic requirements and conserve the ecology of the region should be done Rain water harvesting system: Revive the Traditional water harvesting structure and augment with modern irrigation system.

Guide lines for management of Recreational lakes: Newer recreational development happening should be allowed only if the development takes care of the bird habitats and the fish breeding farm near the lake.

Guide lines for management of Surface water bodies: Sewage, sullage and toxic wastes shall not be allowed to flow in the tank or percolate in the ground. Natural lake edge conditions of the lake to be preserved. No biotic interference inside the lake as washing, boating etc. should be allowed inside the lake. Depth of the lake should be increased by desilting every 3 years. Table 3: Lake Restoration methods

Sl.No Method Advantage Drawbacks 1 Dilution :Flush with low Reduces Nutrient levels, washes out Require large volumes of water. nutrient surface Does not eliminate sources of Water algae phosphorous from, sediments 2 Alum Treatment Lowers lake Phosphorous Content, Reduces the no of beneficial inhibits release of phosphorous from insects in the lake bottom. sediments. Increase water transparency 3 Art ifiilificial Circul ati on Prevents stratificati on, provide Does not decrease alllgal biomass. aeration and oxygenation increase May decrease water clarity. aerobic habitat Adverse impact on cold water fish. No effect on macrophytes. 4 Dredging Controls aquatic vegetation, Temporary resuspension of deepens lake increases lake volume. sediments.Temporory destruction May improve water quality. of habitats. Disposal concern high cost. 5 Water level draw down Control Macrophytes. Consolidate Poor effects in wet, mild climates. sediments ,facilitate dredging or Short term benefits; intensify excavation algal booms. Temporary adverse impact on fish and invertebrates. 6 Biomanipulation Encourage growth of Zooplankton Considered experimental. Not effective Where blue green algae dominate. Conclusion Wastes and effluents from the power plant and other industries pollute the water of Bellundar Lake. Thus it is necessary to have strict regulations for industrial discharge in to the lake. Since all the lakes in Bangalore are interconnected and itinteracti ve it’ s no t enough ht to rest ore onl y B Blldellandur lklake &it& its surrounding catchments area but also overlook into other interconnected wetlands and their catchments areas. The Bellandur Lake holds scope for development of eco-tourism but within some limits. The optimality of the present resource appropriation in light of its sustainability needs to be worked out through further ecological assessments and definite regulatory frame work should be in place. These restoration goals require intensive landscape planning, leadership, and funding, with active involvement from all levels of organization (Governmental, NGO's , corporate sectors , citizen groups, research organizations, media, and so forth) through interagency and intergovernmental processes instrumental in i iti ti d i l ti th t ti THANK YOU