Chennai: Greater Chennai Corporation (GCC) will start imposing fines on households and buildings that illegally let sewage into storm-water drains. Officials said such illegal sewage connections increased from 1.3 lakh in 2023 to 2.1 lakh in 2025.Deputy mayor M Mahesh Kumar said the corporation will give one week’s notice to violators before taking action. “If the connection is not removed, it will be cut off and a fine of 5,000 will be imposed. Larger buildings will face higher penalties,” he said. He also urged residents to stop polluting the drains, as it leads to health issues and blocks storm drains during rains. “GCC has started work to identify and stop illegal sewage discharge in different parts of the city,” he added.In 2024, GCC removed 1,833 illegal sewage connections across the city. A total fine of 5.98 lakh was collected from residents who were found polluting the drains. The highest number of illegal connections was found in Teynampet (zone 9) with 336 cases, where 55,000 was collected as a penalty. Tondiarpet zone followed with 195 illegal connections, and Kodambakkam (zone 10) had 193 such cases.Residents, however, said removing illegal connections alone is not enough. They have asked the civic body to improve the underground drainage infrastructure in areas that lack sewer networks. “Sewage problem emerged as a serious issue in our area. As there is no sewer network here, residents clear the sewage using tanker lorries. But most people illegally drain the household sewage into the SWDs or dump them directly into the Cooum, which results in blockage and overflow during rains, leading to public health problems. City corporation should take mandatory action against violators and prevent overflow of sewage onto the road,” said Arun Chezhiyan, a resident of Chetpet.Popular commercial establishments and hotels near Koyambedu market don’t have any sewer connections. At night, they hire private lorries and illegally dump sewage into water bodies and storm drains in different areas in the city. “Despite several complaints to the Metrowater and assistant engineers, no action has been taken so far,” said D Aravind Kumar, member of Arumbakkam Resident Welfare Association.GCC commissioner J Kumaragurubaran confirmed that the corporation is monitoring key dumping spots. “A mandate on illegal sewage connections will be discussed in the council meeting on Wednesday,” he said.