Greater Chennai Corporation to desilt over 1,000 km of storm-water drains with high-power equipment

Greater Chennai Corporation prepares for city-wide desilting of storm-water drains using high-powered machinery and CCTV documentation.

The Greater Chennai Corporation (GCC) is preparing to begin city-wide desilting of over 1,000 km of the storm-water drain network ahead of the monsoon, to facilitate smoother water flow, and fewer instances of inundation this year.

The project will include photographic documentation, wherein closed-circuit television (CCTV) cameras will be used to capture the state of the drains before and after desilting as proof for implementation, the GCC said. The storm-water drain network in the city extends to 3,040 km, of which 1,084 km has been marked for desilting this year. The GCC will deploy high-powered suction and jetting machines to clean the drains before the rain sets in, according to its Storm Water Drain Department.

The project will employ machinery with vacuum-based technology, the department said in a document. The civic body plans to hire high-power equipment for sucking and jetting (a method to loosen and remove silt). These machines have a minimum capacity to suck 4,000 cubic metre of silt, sludge, and water from drains every hour.

As per the GCC’s documents, rates may vary depending on the size and type of drain. As of now, the cost to desilting a drain the size of 1.2 m x 1.2 m has been fixed at ₹440/m in the south region. In the north region, the same is priced at ₹470/m, while in the Central region, it stands at ₹475/m, the document stated.

GCC Commissioner J. Kumaragurubaran said edge-to-edge paving of roads would be carried out and saucer drains would be installed on bus route roads. “Accumulated dust can be removed by suction sweepers. Tenders have been floated for the purchase of 20 suction sweepers, which can also be operated on smaller roads,” he said.

Saucer drains are surface-level curved drains that run along the edges of the bus route roads and carry off rainwater or surface runoff. Suction sweepers are machines that use a vacuum system to clean streets by collecting dirt, dust, and debris.