HYDERABAD: A hundred years since it began supplying water to Hyderabad, water in the Osmansagar reservoir has nearly touched rock bottom. However, the Hyderabad Metropolitan Water Supply and Sewerage Board (HMWS&SB) continues to draw two million liters of water per day (MLD) using emergency water pumps. Half the monsoon season has passed, and yet the lake has not seen any rise in its water levels.
As per State archives, the reservoir has supplied water to the city since 1920. Though there are ample rains, not much water has flowed into the reservoir mainly because most of the water received in its catchment areas in Vikarabad and Tandur is being used for irrigation purposes.
According to the Indian Metrological Department (IMD) data, the city received slightly excessive rainfall of 394.5 mm since January, against normal rainfall of 318.2 mm. Rangareddy District also received surplus rains, as it recorded 337.1 mm rain against the normal of 270.7 mm. In previous years, both Hyderabad and Rangareddy districts, which form the drainage basin, have usually received excess rainfall. But the water level at the reservoir has barely shown any increase.
The Musi river, which flows into the reservoir from Vikarabad district, is the major source of inflow into Osmansagar and Vikarabad district too received excess rainfall of 488.8 mm against a normal of 371.2 mm.
Data from the Bureau of Economics and Statistics and water board of various rain gauge stations within and surrounding the catchment areas suggests that the conversion of rainfall into inflows has decreased over the years.
The oldest record of HMWS&SB that Express procured from 1961 stated that 36.42 per cent of water got converted into inflow at Osmansagar. The same figure dropped down to 7.42 per cent in 2009. According to experts from the groundwater department, the level of inflow into the reservoir has drastically reduced during the past few decades. Water board officials refused to provide the latest figures.
“The water received in the catchment areas is being impounded with check dams and is being used for raising crops in Vikarabad district and Tandur. This is the reason why Osmansagar is not receiving much inflow,” a source said.