More than 300 people including farmers, local residents, environmental activists, industrialists, educators, students and children staged a one-day hunger strike at Chinnavedampatti against a sewage treatment plant (STP) project.

The Coimbatore Corporation began construction of a 5-million-litres-per-day (MLD) sewage treatment plant (STP) near Chinnavedampatti lake on July 8, 2026, after the Madras High Court disposed of a writ petition challenging the facility.

The STP is a key component of the ₹318.9 crore underground sewerage scheme for Chinnavedampatti, Saravanampatti, and Vellakinar areas. The scheme comprises three sewage pumping mains and six sewage pumping stations.

The writ petition, filed by V.S. Kailasamy, challenged construction and operation of the STP and discharge of sewage into Chinnavedampatti lake. The Tamil Nadu Pollution Control Board granted consent for the project on May 6, 2026. The High Court permitted withdrawal of the petition on June 29, 2026, with liberty to approach the National Green Tribunal.

The treatment plant will use Sequencing Batch Reactor (SBR) technology. Treated effluent will be disinfected per NGT norms with quality monitored through an Online Continuous Effluent Monitoring System (OCEMS) linked to TNPCB and Central Pollution Control Board.

About 5 MLD of treated water will be discharged into the outlet canal of Chinnavedampatti lake flowing to Sulur lake. Corporation officials said work will be completed within one year.

Madras High Court issued interim stay restraining Coimbatore City Municipal Corporation from storing treated sewage water in Chinnavedampatti Lake. Chief Minister MK Stalin had promised during 2024 Lok Sabha campaign to divert surplus Bhavani River water to replenish the lake. Corporation instead proposed treating sewage from surrounding areas, supplying 50% to industries and storing 50% in the lake. Government orders issued and preliminary works initiated. Farmers opposed move citing concerns over soil health, groundwater contamination, and ecological impact. Kalichamy, coordinator of Chinnavedampatti Lake Protection Committee, petitioned Madras High Court alleging sewage treatment plant constructed without mandatory Tamil Nadu Pollution Control Board permission. Court directed CCMC to clarify whether pollution control approvals obtained and instructed no construction proceed without clearance. Case adjourned two weeks after Water Resources Department sought time to respond.

Kaushika Neerkarangal, an environmental organisation, petitioned Collector Pavankumar G Giriyappanavar to restore water streams in Thadagam Valley feeding Chinnavedampatti Lake. The artificial lake, located in Saravanampatti in Coimbatore North, covers about 200 acres and is controlled by the Water Resources Department (WRD). It is a major water source in the northern part of the city.

Main water sources: rainwater from streams in Western Ghats catchment areas through four dams from Chinnathadagam to Kanuvai; the lake receives water through Rajavaikal and Oothuvaikal, each about 8 km long. The lake and Rajavaikal were created in the 1980s by acquiring agricultural lands through the Land Acquisition Act.

Volunteers have worked on the lake for eight years with WRD permission. Since 2017, they have continuously renovated and maintained Rajavaikal with help from volunteers, private firms, and through the state's 'Namakku Naame' project.

Despite complete dredging and repair of Rajavaikal, water does not flow beyond the Pannimadai check dam during rain. Inspections found streams in catchment areas require repair. When repaired, water should collect in small ponds, travel through streams, cross check-dams, and reach Chinnavedampatti Lake via Rajavaikal. The collector directed revenue and WRD to review the places.

Farmers, industrialists and the public continue to oppose the city corporation's move to discharge treated wastewater into Chinnavedampatti lake. The project involves setting up a sewage treatment facility.