T G Halli lake
However in recent years, the inflow to TGR from the two rivers has been decreasing. The quality of the water has also deteriorated. The study carried out by ISRO in association with IN-RIMT revealed that there are number of industries in the catchment area, whose effluents along with underground leachate and sewage flow into the TGR thus affecting the quality of water. In addition to this the unplanned development in the catchment area, the increasing urbanization has led to alteration in the drainage pattern of the TGR catchment area resulting in reduced inflow into the TGR. In 2007, the water level of the reservoir has reduced from 54 feet in 2006 to 17 feet and 8 inches today.
A society, Arkavati Farmers Cooperative Society proposed for setting up of a township on 414 acres of land, near TG halli reservoir. The Special Deputy Commissioner granted permission for conversion of the lands from agricultural to non-agricultural uses.
The Bangalore Water Supply and Sewerage Board (BWSSB) filed appeals before the Karnataka Appellate Tribunal on the ground that establishing of a township near such a sensitive area was injuries to public interests. The Tribunal dismissed the appeals of the Water Board holding that it had no locus standi to present the appeals and its grievance was imaginary. Water board then filed a writ petition before this Court questioning the correctness of the view taken by the Tribunal and on grounds that - by allowing a town ship to come up on the Banks of Arkavathi river, both quality and quantity of water in the river and reservoir would be adversely affected which is injurious to the interest of millions of people residing in the City of Bangalore. Not only there would be depletion of water but also there is every chance of pollution of water. The petition was allowed.
A new proposal was formed which wanted to establish a garden colony instead of a township, on account of serious objections to the township proposal.
State government considered the proposal and constituted an expert committee to consider the matter. The court quashed the orders of converting agricultural land to non-agricultural use.
Later the Government directed the continuance of the permission given for conversion by the Revenue Department for converting these lands for non-agricultural purpose, notwithstanding the earlier order passed by the Court quashing them. Delhi Land and Finance Universal Limited (DLF) got permission to construct the housing colony. This was opposed by Karnataka High court.
The court finally gave an order that nothing is greater than the interests of the people of Bangalore and in public interest, the request of the DLF to put up Housing Colony in the proposed area of the Arkavathi Basin, was rejected, as it will be a sure and permanent source of water pollution and health hazard to the citizens of Bangalore.
The Supreme Court gave the judgment of allowing the project subject to certain conditions. But various public organizations opposed this decision.
Bowing to public pressure, the government withdrew the permission given to DLF to construct the housing complex on the banks of the Thippagondanahalli reservoir.
Under Section 18 (I b) of the Prevention and Control of Pollution Act, 1974 and 1981, the State Government declared the catchment area of T.G. Halli a "regulated zone". So, the industries that had come up in the catchment area were not allowed to let their waste flow into the reservoir. Further development in the catchment area was also restricted by the state. BWSSB, based on a study by the Indian Space Research Organisation (ISRO), found that unplanned development in the catchment area and increasing urbanization had led to alteration in the drainage pattern of the reservoir's catchment area and reduced inflows into the reservoir.
Parisara, the NGO, tied up with BWSSB (Bangalore Water Supply and Sewerage Board) to help citizens participate in the ‘re-greening’ process. Spoorthivana Trust is coordinating the project. The project area comprises 300 acres downstream of T.G. Halli reservoir.
The water level of the reservoir has reduced from 54 feet in 2006 to 17 feet and 8 inches today.
Public interest litigation (PIL) filed by T.M. Uma Shankar and other villagers who challenged the decision of the State and the KSPCB (Karnataka State Pollution Control Board) to allow a hazardous waste treatment plant to be set up near the T.G. Halli reservoir. The court ordered the pollution board to set up the plant in some other areas, and suggested that such hazardous waste treatment plants could be set up in different districts.