NGT: Not enough done to restore Hussainsagar

Precious little work has been done to restore Hussainsagar to its former pristine state, notes a report filed by a joint committee established by the National Green Tribunal (NGT).

The committee, which conducted an inspection as ordered by NGT, said sluice gates and surplus weirs inspected by it in March 2020 are as they were, meaning no repairs have been taken up.

The report underlines that bioremediation of Hussainsagar alone will not be sufficient to protect the lake from pollution, unless pollution from the source level is stopped completely. To prevent influx of pollution from four nalas (drains) coming into the lake, the Hyderabad Metropolitan Development Authority (HMDA) has constructed interception and diversion (I&D) structures to divert the flows based only on dry weather inflows.

Though the height of concrete barriers in naalas has been increased, they would be insufficient in preventing sewage from flowing into the lake during peak and wet weather conditions.

The report further says the Kukatpally nala, which brings in 75 per cent of all waste flowing into Hussainsagar, continues to drain 30-40 per cent of its untreated sewage into the lake. This is despite HMDA telling NGT that the entire sewage is being diverted to the Golnaka nala.

On sluice gates and surplus weirs, the report noted that during an inspection in March 2020, authorities maintained that these would be repaired immediately after the monsoon season. During its next visit, however, the joint committee did not observe any changes in the existing structure.

“The state irrigation department informed that the lake has two surplus weirs and six sluice gates to control floodwater during monsoon. Regular repair work is taken up on them as part of pre-monsoon maintenance to minimise floods due to inflows of water into the lake. These repairs have been taken up in 2015 and 2017. But no repairs have been carried out thereafter,” the report read.

Even worse is the fact that the Sewerage Treatment Plant (STP) at Balkapur nala was not operational due to mechanical failures. Thereby, the entire stream

of sewage has been diverted to Golnaka drain without treatment at Amberpet STP. From Picket nala there is partial mixing.

“Despite recommendations of the joint committee, the state authority has neither installed any flow measurement devices nor adopted any method of quantifying the actual quantum of sewerage generated,” the report said.

The committee recommended increase of aerators to improve dissolved oxygen (DO) levels in the lake. Presently there, are seven high jet fountains or aerators in the lake.