The Kolkata Municipal Corporation (KMC) has started scraping off the top layer before re-laying it on relatively narrow roads like BB Chatterjee Road in Kasba and Sarat Ghosh Garden Road in Dhakuria after similar work on arterial roads like Park Street and CR Avenue was done earlier.
When a fresh layer used to be laid earlier, the existing top layer was rarely removed or scraped off. The Telegraph reported in 2019 that large parts of Calcutta were “sinking” below the road level because of laying bitumen on the roads over the years without scraping off the existing ones.
Rainwater from waterlogged streets enters ground floor rooms in many houses as the height of roads has become higher than houses on their periphery. Residents across the city complain that roads were much lower when they built their houses.
Uneven and undulating surfaces are another feature of almost all roads in Calcutta. Patchwork on broken roads is done hastily and without care and these end up forming undulated surfaces. Cars and buses move jerkily on the bumpy surface of these roads.
The KMC wants to put an end to this practice and see that road levels do not go above houses along the road.
Scraping off the older layer, as is being done on BB Chatterjee Road, will guarantee that the road’s overall height does not rise further, said a senior official of KMC.
“Henceforth, the top layer on all roads that are 5m-wide or more will be removed before laying a fresh top layer. We are now laying a fresh top layer on BB Chatterjee Road after scraping off the old layer. We have plans to take up such projects on a few more roads in the coming months, before the next monsoon,” said the official.
The KMC is yet to focus on lanes and bylanes inside localities, which means many houses along such lanes whose heights have increased will remain vulnerable to flooding during monsoon.
The KMC has four milling machines, three of which have drums that can scrape off 1m width of asphalt from a road. A fourth one has a narrower drum. A wide section of the road is scraped off by running the machine over it multiple times.
“We will procure five more road milling machines so we can take up projects on many roads simultaneously or can finish the work on one road faster by deploying multiple machines,” said a KMC official.
The use of milling machines depends on the condition of the roads. Some roads that become battered or whose top layer wears off need a fresh top asphalt layer. The milling machine is used to scrape off the top layer on the entire length of such a road.
On other roads, only the uneven portions are scraped off to flatten the surface because the rest of the surface is still in good condition. “We removed only select portions on Park Street when we flattened the surface recently,” said the official.
The work to remove the undulated stretches on Park Street has been completed between the Park Street-Chowringee crossing and the Mullick Bazar crossing. Such undulations on the rest of Park Street, from Mullickbazar to Park Circus, remain.
“We have also removed undulations on a stretch of CR Avenue, a stretch of AJC Bose Road, on the entire length of SN Banerjee Road and Ripon Street,” added the official.