The official said the height of many lampposts got reduced owing to re-erecting of rusted posts. Of the seven zones, as many as 1,670 lamp posts would be replaced in Tondiarpet zone.

Apart from replacing the rusted lampposts, the civic body also had prepared a detailed project report for replacing underground cables extending up to 131.97 kilometres. “As the underground cables were also laid more than 15 years ago, they got damaged. Whenever any fault occurs, it has become difficult to attend cable faults,” the official said.

Of the seven zones, underground cables of a total length of 20,856 metres will be replaced, which is the highest. In overall, the civic body has estimated around Rs 44 crore to replace the lamp posts and underground cables.

Explaining the need for replacing the underground cables, the official said the cables have joints in every 25-metre span. The move would also improve the safety of the street-light installations and minimise the downtime of streetlights. It is learnt that the civic body had sent a proposal to the State government seeking administrative sanction and the works are expected to start in a few months.