The proposal to make navigable the 722-metre Sivagiri tunnel, the 350-metre Chilakoor tunnel, and the 12.7-km waterways between Nadayara and Kovilthottam is still confined to paper.
The tunnels and the 12-7 km long waterways are part of the 60.5-km Thiruvananthapuram-Kollam section of the T.S. Canal. The adjacent Kollam-Kottapuram stretch of the West Coast Canal has been declared as National Waterway III (NW III) and is ready for commissioning.
Dredging, widening, and reinforcement work was chalked out to make the stretch navigable and extend the NW III up to Kovalam. A sum of Rs.27.5 crore was also sanctioned by the Coastal Shipping and Inland Navigation Department to the Irrigation Department for the works in August last year.
Official sources told The Hindu that the works sanctioned for the Thazhevettoor to Ramanthaly section for Rs.19.5 crore and Ramanthalay to Sivagiri for Rs.8 crore could not be taken up. Administrative sanction was given based on the proposal from the Irrigation Department.
The assessment that the sanctioned funds would not be sufficient for completing the works had confined the project again to paper. The Irrigation Department was revising the estimate, sources said. The tunnels and the waterway date back to 1880, when it was completed by Diwans T. Madhava Rao and Seshaya Sastri during the reign of Sree Ayilyam Tirunal. The canals were intended to improve connectivity between Thiruvananthapuram and Tirur.
The proposal is to create a 14-metre wide, two-metre deep waterway on the 12.7-km stretch for boats to pass. The Sivagiri tunnel, completed in 1880, is reported to be the only one of its kind in Asia.
Concrete lining was provided between 1934 and 1942 and these have come off at several places. Although it rises to a height of five metre, siltation restricts the air draft to 1.3 metre, affecting the flow of water on either side.
An official of Vision Varkala Infrastructure Development Corporation Ltd., which spearheads the development of Varkala, said they were putting pressure on the authorities for the revival of the tunnels and waterways.