Roads in the city are vulnerable to cave-ins as the civic body has no mechanism in place to detect seepage, corrosion and erosion in the utilities running beneath the ground.
There are only three roads — E. Moses, P. D’mello and Patthe Bapurao Marg — for which the Brihamumbai Municipal Corporation’s storm water drain (SWD) department has done a detailed study of the underground utilities.
Experts said the main reason roads are collapsing are because the century-old utilities laid in the British era are leaking and need to be changed.
Civic officials said the long-term solution is their replacement under the Brihanmumbai Storm Water Drain Project (Brimstowad).
However, under this, of the 58 projects the BMC has to complete, work has yet to begin on 11, and these mainly include replacement and concretisation of old, underground drains.
“The tenders to replace the first three arch drains will be floated by the end of this month. Apart from those drains that have collapsed earlier, we have not yet started replacing them,” an official said, requesting anonymity.
The BMC will start by replacing the drains on the three roads that are mapped. It aims to complete the Brimstowad project by May 2012. Till the work is done, the only way officials detect the condition of the underground drains and utilities is when there’s a cave-in.
“We have data of which drain goes where, but conditional survey and mapping have not yet been carried out,” said Chandrakant Watwe, chief engineer, SWD department.
There are about 152 km of storm water drains in the city.
The stretch that collapsed on Wednesday had been laid with paver blocks just two years ago. “It could be possible that the contractors just did a superficial job and did not check the underground utilities while laying the paver blocks,” said an official. The stretch was not marked as high priority as by visibly there were no damages.