Sewer manhole collapses in Old Malakpet

The drain slab that had caved in at Banjara Hills on Tuesday, taking down a tanker along, in the aftermath of the heavy rain on Monday, is a grim reminder about the status of drains in the core part of the capital city.

Close on the heels of the incident on Wednesday, one more sewer manhole of the Hyderabad Metropolitan Water Supply & Sewerage Board collapsed at Panchasheela, Old Malakpet.

Not very long ago, repeated collapse of another drain at Chaknawadi area of Goshamahal, resulted in heavy losses for small time traders in the area, as a truck and several two wheelers fell into the drain along with the slab.

All these instances are indicative of the fact that vital infrastructure is crumbling underneath the blacktop in the city. While hundreds of crores of rupees are being spent on adding to the drain network by way of Strategic Nala Development Programme, the Greater Hyderabad Municipal Corporation has been ignoring the need for maintenance of the existing storm water drains.

The city has a total 1,302 kilometres of drain network, which includes major, medium and minor nalas. Of this, 383 kilometres are major drains. A predominant percentage of these drains falls within the core city, and has aged considerably.

“Most of these drains are over 40 years old, and are in need of repairs. They are all RR masonry [Random Rubble masonry] drains, while the modern ones are of RCC. However, the drain that collapsed in Banjara Hills had its sidewalls intact,” a senior Engineering official from GHMC said.

An estimate of ₹68 lakh has been submitted to the zonal commissioner for restoration of the slab, he informed. The drain joins the Bulkapur nala coming from Ahmednagar. The official however admitted that the old drain network is in dilapidated condition, and the issue had been taken cognisance of.

In Chaknawadi, the drain was repaired in bits and pieces whenever a collapse incident happened. Of the 360-metre drain, 200 metres has been renovated, and a proposal has been sent to the government for renovation of the remaining part.

Continuous flow of sewage even during dry season affects the soundness of the drains, officials say. Methane gas released from the faecal waste over time, results in formation and thriving of corrosive substances, which eat into the masonry and even concrete structures. The drains of the city are also host to a variety of chemical pollutants, which only add to the corrosion.

Workers at the collapsed drain in Banjara Hills witnessed rosy tinted effluents rushing through the drain, the source of which was not known. Preliminary enquiries revealed that the colour was owing to a clothes dyeing unit which was letting the waste water into the drain.