Significant Decline in Water Storage Capacity of Telangana’s Lakes Sparks Concern
Telangana's reservoirs, particularly freshwater lakes that serve as sources of drinking water, have lost up to a quarter or more of their storage capacity due to decades of neglect in removing silt and sediment.
Hyderabad: Telangana’s reservoirs, particularly freshwater lakes that serve as sources of drinking water, have lost up to a quarter or more of their storage capacity due to decades of neglect in removing silt and sediment.
According to surveys of 14 projects conducted over recent years, sand and other sediments have slowly occupied space where 35.15 TMC ft (thousand million cubic feet) of water could have been stored. This volume is 35 times the capacity of Hussain Sagar and exceeds the combined capacity of the Upper and Lower Manair Dam projects, along with Suddavagu, Mathadivagu, Dandi, and Swarna projects.
Among the affected reservoirs is Himayat Sagar, which, along with Osman Sagar, provides drinking water to Hyderabad. Interestingly, the previous BRS government attempted to remove these two lakes from the list of drinking water sources.
According to the Central Water Commission’s (CWC) 2020 ‘Compendium of Silting in Reservoirs in India,’ Himayat Sagar is one of the reservoirs that has lost more than a quarter—26.56%—of its storage capacity. Similarly, silting has impacted Osman Sagar, where the water spread has reduced to 6,300 acres from its original 10,000 acres.
Nizam Sagar has suffered the most, with the CWC report indicating a 60.47% loss in its storage capacity. Due to siltation, the capacity of Nagarjuna Sagar reservoirs has dropped by 23.52%, and Srisailam reservoirs by 29.96%.
An official from the Irrigation Department highlighted the severity of the problem, stressing that immediate action is needed as the dead storage levels of several reservoirs are being affected. For example, the Singur project on the Manjeera River saw its total storage drop from its original 29.917 TMC ft to 29.178 TMC ft, while its dead storage level fell from 0.872 TMC ft to 0.279 TMC ft. Similarly, the dead storage in the Komaram Bheem project has been halved from 1.785 TMC ft to 0.872 TMC ft.
The department has begun identifying methods and processes to restore at least part of the lost storage capacity of the reservoirs. Officials stated that global tenders are being prepared for desilting the reservoirs, but they cautioned that the process will take several years to recover even a portion of the lost water-holding capacities.
