Sankey Lake: waiting for an Immediate Sensible Action

T.V. Ramachandra*    Asulabha .K S  Sincy .V. Vinay .S Sudarshan p. Bhat Bharath H. Aithal
Energy & Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012
*Corresponding author:,
Landscape Dynamics: Violations and encroachments in Sankey Valley


Shrinking water body and loss of interconnectivities among lakes




Encroachment of lake bed and raja kaluves (storm water drains)




  • “Preservation of Lakes in the City of Bangalore” Report of the Committee constituted by the Hon’ble High Court of Karnataka to examine the ground realities and prepare an action plan for preservation of lakes in the City of Bangalore. (Hon’ble High Court of Karnataka’s Order dated 26/11/2010 in WP NO.817/2008 & others),
  • Lake area should not be diverted for any other purpose as lakes have an increased and important role to play vis–a-vis lakes in rural areas, like ground water recharge, climate moderation, act as lung spaces, water for various purposes, urban recreation etc
  • Currently 30m buffer space needs to be maintained as per the BDA from the legal lake boundary (wetland) free of any developmental activity.
  • Lake preservation has to be integral to Layout Development by BDA and Layout approvals by development and planning authorities like BIAPA, MICAPA, Nelamangala Planning Authority, Hosakote Planning Authority etc., as eventually these areas will be part of Bangalore city.
  • BDA should not acquire lake area at the time of notifying the area for development and allot sites in the lake area as was done in many a layout development previously. Instead they have to properly get all the lakes, raja kaluves, drains surveyed and marked on the ground as per village records with boundary stones and make provisions for buffers as laid out in their norms.
  • Lake preservation is not limited to lake area itself, but very much dependent on catchment area and the drains that bring rainwater in to the lake. Raja kaluves, branch kaluves are to be surveyed and encroachment therein needs to be evicted.
  • Effective Lake area should not be reduced by converting lake area into parks, children play grounds, widened bunds etc. The desilting has to be minimized to remove only sludge portion with minimum depth near foreshore reaching maximum depth at the bund.


  • Violation as per BDA, RMP 2015; Section 17 of KTCP Act

In case of water bodies, a 30.0 m buffer of ‘no development zone’ is to be maintained around the lake (as per revenue records)

  • As per BDA, RMP 2015
  • Section 17 of KTCP Act, 1961 and sec 32 of BDA Act, 1976
  • Wetlands (Conservation and Management) Rules 2010, Government of India; Wetlands Regulatory Framework, 2008.
  • Construction activities in the valley zone:

This is contrary to sustainable development as the natural resources (lake, wetlands) get affected, eventually leading to the degradation/extinction of lakes. This reflects the ignorance of the administrative machinery on the importance of ecosystems and the need to protect valley zones considering ecological function and these regions are ‘NO DEVELOPMENT ZONES’ as per CDP 2005, 2015

  • Violations of National Water Policy, 2002

Water is a scarce and precious national resource and requires conservation and management.
Watershed management through extensive soil conservation, catchment-area treatment, preservation of forests and increasing the forest cover and the construction of check-dams should be promoted
The water resources should be conserved by retention practices such as rain water harvesting and prevention of pollution

  • Wetlands (Conservation and Management) Rules 2010, Government of India; Wetlands Regulatory Framework, 2008.

Prohibited Activities

  • Conversion of wetland to non-wetland use.
  • Reclamation of wetlands
  • Solid waste dumping and discharge of untreated effluents.

Regulated activities

  • Withdrawal of water/impoundment /diversion/interruption of sources
  • Harvesting (including grazing) of living/non-living resources (may be permitted to the level that the basic nature and character of the biotic community is not adversely affected.)
  • Treated effluent discharges – industrial / domestic/agro-chemical.
  • Plying of motorized boats
  • Dredging (need for dredging may be considered, on merit on case to case basis, only in cases of wetlands impacted by siltation)
  • Constructions of permanent nature within 50 m of periphery except boat jetties.
  • Activity which interferes with the normal run-off and related ecological processes – upto 200 m (Facilities required for temporary use such as pontoon bridges and approach roads, will be exempted)
  • Water (Prevention and Control of Pollution) Act, 1974
  • It is based on the Polluter paysprinciple

Action Plan

  • Good governance (too many para-state agencies and lack of co-ordination) - Single agency with the statutory and financial autonomy to be the custodian of natural resources (ownership, regular maintenance and action against polluters (encroachers as well as those let untreated sewage and effluents, dumping of solid wastes).
  • De-congest Bangalore: Growth in Bangalore has surpassed the threshold evident from stress on supportive capacity (insufficient water, clean air and water, electricity, traffic bottlenecks, etc.) and assimilative capacity (polluted water and sediments in water bodies, enhanced GHG – Greenhouse gases, etc.)
  • Disband BDA – creation of Bangalore Development Agency has given impetus to inefficient governance evident from Bangalore, the garden city turning into ‘dead city’ during the functional life of BDA.
  • Digitation of land records (especially common lands – lakes, open spaces, parks, etc.) and availability of this geo-referenced data with query option (Spatial Decision Support System) to public.
  • Threshold on high raise building in the region. Need to protect valley zones considering ecological function and these regions are ‘NO DEVELOPMENT ZONES’ as per CDP 2005, 2015
  • Evict all encroachments from lake bed and raja kaluves
  • Reestablish interconnectivity among lakes
  • Restoration of lakes

Unplanned rapid urbanisation during post 2000 witnessed large scale conversion of watershed area of the lake to residential and commercial layouts. This has altered the hydrological regime and enhanced the silt movement in the catchment. Declining vegetation cover has lowered water yield in the catchment, affecting the groundwater recharge. Alterations in ecological integrity is evident from reduced water yield, flash floods, contaminated water, obnoxious odour, copious growth of invasive floating macrophytes,  disappearance of native fish species, breeding ground for mosquito and other disease vectors,  etc. A major portion of untreated city sewage (500+ million liters per day) is let into the lake, beyond the neutralizing ability of the lake, which has hampered the ecological functioning of the lake.
Ecological and Environmental Implications:

  • Land use changes: Conversion of watershed area especially valley regions of the lake to paved surfaces would alter the hydrological regime.
  • Loss of Drainage Network: Removal of drain (Rajakaluve) and reducing the width of the drain would flood the surrounding residential as  the interconnectivities among lakes are lost and there are no mechanisms for the excessive storm water to drain and thus the water stagnates flooding in the surroundings.
  • Alteration in landscape topography: This activity alters the integrity of the region affecting the lake catchment. This would also have serious implications on the storm water flow in the catchment.
    The dumping of construction waste along the lakebed  and lake has altered the natural topography thus rendering the storm water runoff to take a new course that might get into the existing residential areas. Such alteration of topography would not be geologically stable apart from causing soil erosion and lead to siltation in the lake.
  • Loss of Shoreline: The loss of shoreline along the lakebed results in the habitat destruction for most of the shoreline birds that wade in this region. Some of the shoreline wading birds like the Stilts, Sandpipers; etc will be devoid of their habitat forcing them to move out such disturbed habitats. It was also apparent from the field investigations that with the illogical land filling and dumping taking place in the Bellandur lakebed, the shoreline are gobbled up by these activities.
  • Loss of livelihood: Local people are dependent on the wetlands for fodder, fish etc. estimate shows that wetlands provide goods and services worth Rs 10500 per hectare per day (Ramachandra et al., 2005).  Contamination of lake brings down goods and services value to Rs 20 per hectare per day.

Sankey Lake: Sankey Lake is an artificial lake that was built by Col: Richard Hieram Sankey, in 1882 to meet the water supply demands of Bangalore to safeguard against water shortages experienced during great Famine in 1875 to 1877. The lake was also known as the Gandhadakoti kere, and was linked to Dharmambudi Lake and Millers tank in order to cater the water needs (Source: Figure 3.1)

Figure 3.1: Brief description of Sankey lake.

Figure 3.2: Cadastral map of Sankey lake As per BBMP records (


Spatially, legal lake boundary (Figure 3.2) as per the BBMP records spreads for about 16.89 Hectares (41.75 acre), whereas considering the immediate water body (not considered in BBMP map), area was 17.2Hectares (42.76 acres). The tank has maximum depth of 9.26 m. Sankey tank spatially is located in the north western part of  Bangalore (Figure 3.3) at an elevation of 929.8m above mean sea level.
Landscape Dynamics in and around Sankey Lake: Figure 3.4 temporally and spatially describes the land use dynamics within 30 m (BDA norms) buffer of Sankey Lake and upto 200 m (MoEF &Climate change). The development of the tank has been taken into account post 2004 where in a small tank was built within the lake in order to avoid pollution of the lake due to submerging idols, paved walk ways were built for the walkers, aerators were deployed etc.

Figure 3.3: Sankey Lake

Within the study area (Figure 3.5) i.e., up to 200m buffer, Built-up area is about 36.88 Hectares (91.16 Acres), green cover and public utility (open areas, parks, swimming pool) accounts to an area of 17.95 Hectares (44.29 Acres).
Violation of bylaws in and around Sankey Lake: Sankey tank in its buffer zones is no different to other wetlands or lakes. The buffer zone have been found to violate the bylaws laid by both BDA (30 m) and MoEF (200 m), large residential construction activities have come up in the zones and still are being proposed to come up in the buffer zones. The proposed construction of residential complex will be in violation of norms. Figure 3.6 and Figure 3.7 depicts the violations that has occurred in the buffer zones. Within 30m buffer the existing built up area is about 2.7 Hectares (7.10 Acres), whereas with in the 200 m buffer zone, 36.88 Hectares (91.16 acres).  

Figure 3.7 depicts the violation of the BDA and MoEF, GoI norms for protection of wetlands; the proposed apartment complex adjacent to the lake’s legal boundary will adversely affect the ecological functioning of the lake apart from likely environmental consequences (associated with such massive construction of high raise building) on groundwater, surface water quality, aesthetics of the lake, hydrologic regime, etc.







Figure 3.4: Landscape dynamics around Sankey Lake

Figure 3.5: Land use around Sankey Lake

30m buffer zone

200m buffer zone

Figure 3.6: Violations of bylaws (built up area) around Sankey Lake

Figure 3.7: Violation of bylaws overlaid on Google earth


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