The Brihanmumbai Municipal Corporation (BMC) has finally decided to do something about the erosion of the city’s roads from large-scale digging.
The corporation plans to shift all underground utilities into ducts to ensure any work on them does not require digging up the entire road. It will be constructing six such ducts on a pilot basis and if successful, replicate the model elsewhere. It is also mapping every utility across the city that will help prevent haphazard trenching.
BMC engineers have blamed large-scale, continuous trenching for the state of the city’s roads, saying it affects their upper layers and leads to water seepage. Moreover, poor reinstatement leads to top layers becoming pockmarked.
Former municipal commissioner Ajoy Mehta had even framed a policy that stipulated that all trenching works by agencies need to be undertaken at the same time.
“But sometimes, private agencies cannot help it when there is an emergency. That is why we realised that shifting the utilities could be a good option. In that case, whenever they need to be repaired, the road will not have to be dug up,” said a roads department officer.
In some Western countries, all utilities run inside these ducts that have entries at regular intervals. However, the ducts have sophisticated mechanisms such as CCTV networks, ventilators, fire safety measures, and so on. The BMC is planning six such ducts in the city on a pilot basis — two each in the island city, eastern suburbs and western suburbs. The underground ducts will be designed by an agency, following which they will be introduced during road work.
“The idea is that once a road is built, there should be no need to dig it up unless the road itself is being repaired. However, designing the ducts will be the biggest challenge, since they will have to accommodate the needs of every department. For example, the lines of piped natural gas and electricity cannot be next to each other. They have to be at separate levels. Also, our own water department will face an issue as the water mains will have to be carefully placed. If a pipeline bursts, it can flood the duct,” said the officer. The ducts will need to have arms in several directions to ensure services reach users.
There are 17 types of utilities in Mumbai, and the BMC wants to map each one of them. “We too don’t know what kind of network lies underground. There is need to have a comprehensive blueprint of our underground utilities. We will be inviting expressions of interest,” said Vinod Chithore, director (engineering services and projects). An agency will be appointed to undertake this survey and submit a report.
