ASI finds Erode’s Kalingarayan Canal aqueduct structurally stable

The Archaeological Survey of India (ASI) has found the historic aqueduct of the Kalingarayan Canal in Erode to be structurally stable and concluded that the only significant issue affecting the monument is water seepage through masonry joints, which can be arrested through conservation measures.

The 743-year-old Kalingarayan Canal, along with the Kalingarayan Anicut, was recognised as a World Heritage Irrigation Structure by the International Commission on Irrigation and Drainage (ICID) in 2021. Built by Kalingarayan, the ruler of Poondurai Nadu in Kongu Nadu, between 1270 and 1282, the 91.10-km canal irrigates 15,743 acres in Erode district.

The 41-metre-long aqueduct, regarded as Tamil Nadu’s earliest surviving canal aqueduct, spans the Perumpallam Odai at Karai Vaikal at the 13.7/260th mile of the canal. With 14 vents, the structure is considered a significant example of medieval Tamil hydraulic engineering.

Opposition to demolition

The Water Resources Department (WRD), through Government Order No. 39 dated July 24, 2025, sanctioned ₹83.30 crore for renovating the canal between mile 12-3-348 and mile 15-4.5-195. The proposal included demolishing the aqueduct and constructing a new one, citing excessive seepage and inadequate vent size. However, the plan was dropped in March this year following opposition from farmers, the public, and heritage enthusiasts.

Researcher and author K. Banuchandar moved the Madras High Court seeking to protect the aqueduct. The WRD’s Lower Bhavani Basin Division also sought an inspection by the ASI before proceeding further. On April 2, 2026, a team led by C. Baranidharan, Deputy Superintending Archaeological Engineer, ASI, Chennai Circle, inspected the structure along with officials of the WRD.

ASI findings

In its report submitted to the court, the ASI observed extensive root penetration due to inadequate maintenance. Persistent moisture from seepage and silt deposits had encouraged vegetation growth, while plants inside the vents had reduced the flow area and contributed to garbage accumulation.

The report, however, found no signs of structural displacement or tilting of the piers. Their alignment remained intact and no major cracks were noticed. It observed minor dislodgement of masonry stones on the upstream side of the abutment, resulting in open joints that allowed water seepage. The deterioration was attributed primarily to root penetration.

The ASI concluded that the main channel structure was in good condition and that no major structural damage or failure had been detected. It recommended grouting the masonry joints and sealing the open joints on the inner face of the channel to stop seepage and ensure the structure’s long-term stability.

The report also pointed to sewage discharge and garbage accumulation in the Perumpallam Odai as a major concern, recommending that the State government provide a separate drainage channel to prevent wastewater from entering the stream and blocking the aqueduct’s vents. It further noted that the interior of the channel could not be inspected as water was flowing during the visit and recommended a detailed examination after the canal is dewatered.

Mr. Banuchandar told The Hindu that the report vindicated the demand to preserve the aqueduct, adding that its findings demonstrated that scientific conservation and restoration were feasible and that demolition was unnecessary. He urged the State government to preserve and strengthen the historic structure instead of replacing it.