Mumbai, Feb. 2 — A group of collegians enjoy their walk along the new promenade that hugs the landscaped periphery of Powai lake.

On the surface, all appears well with Powai, one of the three major lakes of Mumbai and among the 10 included in the National Lake Conservation Plan in 1995. But buried in its shallow depths, lie vast amounts of silt, chemicals, debris and perhaps a whole lot of taxpayers’ money.

The civic body is spending Rs 22.65 crore to de-silt the lake of the debris deposited through years of hill quarrying by the powerful builders’ lobby. Powai lake is an important part of Mumbai’s ecosystem.

It is part of the green zone that stretches from Sanjay Gandhi National Park to the no-development zone at the south of Hiranandani Complex. The lake supports a variety of migratory birds, fish, eight or nine crocodiles and a small population of turtles.

The large silt deposits are worrying because they can cause an overflow into the Mithi river, leading to a flood similar to the one on July 26, 2005. The British artificially created Powai lake in 1891 as an emergency measure at a cost of Rs 6.5 lakh to supplement the city’s drinking water supply by recharging the area’s underground water table.

Ironically, the water of the lake has proven to be non-potable through the years and is only supplied for industrial purposes. A Right To Information (RTI) query filed in November 2009 by S.K. Saksena, a former director of Siemens and member of the Powai Residents Welfare Association, revealed that the de-silting contract was awarded to Chembur-based Raj Engineers and Aakash Engineering Consultants.

“The contract was given to a firm that had no experience in such specialised projects. This is against all established norms,” said Saksena.

In the RTI report, the office of the Deputy Hydraulic Engineer (the designated guardian of the lake) stated that 40,807 truckloads of silt were transported out of Powai. By this estimate, nearly 56 trucks of wet silt would have been transported every day since October 2007, when the work started.

But according to J.A. Shah, another citizen activist, “None of the residents living near the lake have seen so many trucks on Adi Shankara Marg in the past two years.” Saksena, an engineer, said the machines used by the contractors are “children’s toys” and that no large water dredgers, required to excavate silt deposits, were used.

“The contractors are merely nibbling away at the edges, removing surface silt and weeds to give the appearance of depth,” he claimed. Justifying the work, civic Executive Hydraulic Engineer M.S. Pawar said: “Water-level surveys taken before and after de-silting show a considerable increase in the lake’s capacity.

Records of this are available at the site office and can be checked by those unsure of the progress.” Nonetheless, the activists plan to file another RTI query to investigate the technical know how of the contractors and the equipment used.

This is not the first time Powai residents have raised their guard. In 2005, the Centre released Rs 4.46 crore to the state government to save the lake.

The Brihanmumbai Municipal Corporation (BMC) awarded the contract to Ace Housing Corporation, which spent the money on bioremediation (oxygenation of the lake) instead of restoration of the lake’s depth by de-silting. Activists from NGOs such as AGNI and Citispace alleged that the company never existed, that no sampling of water was done to test the effectiveness of the bioremediation and that the Rs 4.66 crore remained unaccounted for.

“When I moved here in 1995, my building was surrounded by green hills and mango orchards. I had a brilliant view of Powai and Vihar lakes,” said Saksena, who has been battling to save the lake for nearly 10 years.

Now, all he can see are barren hills and towering buildings. While the quarrying has ceased, the damage has been done.

Hindustan Times