The Tamil Nadu government is advancing plans to interlink the Pennaiyar and Cheyyar rivers to improve irrigation for the Nandan canal system and support agricultural activities across approximately 9,000 acres in the Villupuram and Tiruvannamalai districts.

The State Water Resources Department (WRD) has submitted a detailed project report (DPR) for Phase I of the scheme, with an estimated cost of Rs 3.9 billion. The proposal involves the excavation of a 12.45-kilometre main canal and a 16.55-kilometre feeder canal, drawing water from the foreshore of the Sathanur Reservoir to the Keeranur Dam via Samuthiram Lake and the Olaiyar.

The scheme is expected to benefit 2,609 acres across 22 tanks in Tiruvannamalai district and 6,653 acres across 36 tanks in both Villupuram and Tiruvannamalai. Initially proposed in 2021, the plan was put on hold due to lack of funding, but was revived following Chief Minister M. K. Stalin’s announcement during a government event in Villupuram earlier this year.

The WRD revised and submitted the DPR in February 2025 after analysing 35 years of flood and rainfall data in the Sathanur Reservoir catchment. The current plan proposes the diversion of 0.475 tmc (thousand million cubic feet) of surplus water—out of 0.76 tmc available—to Samuthiram Lake by gravity. From there, the water will flow to Keeranur Dam via Oolaiyar and Thirunalaru.

To implement the project, the government will need to acquire 345 acres of land, including 276 acres of patta land, 35 acres of poramboke land, and 34 acres of forest land. “We are optimistic about receiving approval for land acquisition soon, followed by administrative clearance, as the project will benefit 67 villages across the two districts,” a WRD official stated.

The second phase of the scheme proposes a connection to the Nandan canal from the left sluice of Keeranur Dam. However, this would require an estimated 5.8 tmc of surplus water. Although the dependability is just 35 per cent, the second phase aims to harness excess flows during heavy rainfall or cloudbursts. The Pennaiyar, which receives substantial inflows every three to five years, would also benefit from flood mitigation through this extended linkage.