Rain fails to slake City's thirst

The total height of the reservoir is 74 feet spread across 1,200 sqkm with a storage capacity of 3,345 million cubic ft (3.3 tmc feet). However, as per Monday’s recording the water level at TG Halli reservoir is just 19 feet 7 inches. Bangalore receives nearly 18 to 20 Million Litres per Day (MLD) of water from the reservoir.

There is no increase in the water level as many borewells have been sunk in the reservoir area, said a BWSSB official. The inflow of water to the tank bed is poor. In 2008, the water level in TG Halli reservoir rose to 45 ft, but of late the level remains a mere 19 or 20 feet, he added.

Thippagondanahalli Reservoir (TGR), also known as T G Halli Dam or Chamarajasagar, is located at the confluence of the Arkavathy River and Kumudavathi River, 35 km west of the City.

The man-made reservoir was created by the building of a dam in 1933.   The total extent of TGR catchment is 1453 sqkm and covers parts of Doddaballapur, Nelamangala, Devanahalli, Magadi and Bangalore taluks.

In recent years, the inflow to TGR from the two rivers has been decreasing.
The quality of the water has also deteriorated. A study carried out by ISRO in association with Indian Resource Information and Management Technologies revealed that there are a 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 urbanisation has led to alteration in the drainage pattern of the TGR catchment area resulting in reduced inflow into the TGR.

Dr V S Prakash, Director, Karnataka State Natural Disaster Management Cell (KSNDMC) said the TG Halli reservoir received water only in the months of October and November.
Change in the land use pattern is one of the primary reason contributing to the decline in inflow to the reservoir.

The BWSSB has formed an expert committee to draw plans to fill the reservoir to its full capacity, he said.

Ishwar Prasad Parisara, Convener of Spoorthivana, an NGO which focuses on increasing the green cover of the catchment area of TG Halli reservoir, said indiscriminate sinking of borewells around Nandi Hills and manipulation of catchment areas have led to drying up of the Thippagondanahalli reservoir.