Brick structures that were found on the Kollidam river bed at Koogur near Lalgudi in Tiruchi district, close to the ancient Kallanai dam, a few days ago are probably the remains of a Sangam-age irrigation structure, according to the Archaeological Survey of India (ASI).

“Brick remains were identified at two places on the river Kollidam, about 500 metres to the south of the Moongil Karuppar Temple. The first was a semi-circular brick wall, of which only two courses were visible above the water. The second, located to the east, was fully submerged. Underwater observation revealed two walls running parallel to each other, with a gap between them, suggestive of an entrance or a channel opening,” P. Aravazhi, Superintending Archaeologist (in-charge), ASI, Tiruchi Circle, told The Hindu.

The exposed portion was a linear masonry structure built with large bricks and stones. The archaeologists documented the exposed portion of the brick structure measuring approximately two feet in height and four feet in width during the inspection. “Based on its structural characteristics, it has been provisionally identified as an inlet channel of possible early historic period [3rd-4th century CE],” said Mr. Aravazhi.

The characteristics of the construction, the use of large-sized bricks and the location suggest that the structure could be the remnants of an ancient water regulation structure, possibly a sluice or an inlet or outlet channel, he added.

The structures were found by the villagers in a pool of water stagnant in the river bed. Photographs of the structures were posted on social media by a group of youths from the village following which a team of archaeologists from the ASI’s Tiruchi Circle, led by Mr. Aravazhi, inspected the structures on Tuesday.

According to the archaeologists, bricks from both structures were rectangular and wedge-shaped, with a consistent dimensional ratio. The structural remains are broadly comparable to the water management structure exposed at Vanagiri near Kaveripattinam (Poompuhar). Excavations at Kaveripattinam carried out several years ago had revealed a brick-built inlet sluice/channel associated with reservoir, Mr. Aravazhi said.

“The large-sized bricks and constructional characteristics seen here are suggestive of an Early Historic/Sangam period structure. However, its exact period can be established only after systematic excavation and scientific dating of the materials,” he said.

Published - August 12, 2026 05:53 pm IST