The newly built regulator across the Kollidam river at Mukkombu (Upper Anicut) near Tiruchi was formally commissioned by Chief Minister M.K. Stalin through video conference from Chennai on Tuesday.
The regulator has been constructed at an estimate of ₹414 crore after a portion of the 182-year-old old barrage collapsed on August 22, 2018, due to heavy discharge in the river. The old regulator across the river was constructed in 1836.
The new regulator, which is already functional, has been constructed 75 metres away from the damaged structure on the downstream of the riverbed. Construction of the new barrage began in March 2019 and was scheduled to be completed in two years. But the contractors, Larsen and Toubro, executing the work on behalf of the Water Resources Department, had to contend with intermittent suspension of works due to the pandemic and periods of heavy water discharge in the river.
The new regulator is 767.50 metres long with 55 vents. The regulator is 628 metres long with 45 vents on the southern side and 139.50 metres long with 10 vents on the northern side. It has a capacity to discharge 2,83,000 cusecs of water in the Kollidam.
In a first of this kind in Tamil Nadu, the discharge of water will be monitored from the Motor Control Centre Building through a computerised system equipped with modern technology Supervisory Control and Data Acquisition (SCADA), WRD officials said.
The river bund from Mukkombu to Tropical Butterfly Conservatory in Srirangam was also strengthened and made motorable as part of the project, providing a direct link between the two popular picnic destinations in Tiruchi.
For farmers, the commissioning of the new barrage would bring a sigh of relief as it is from here that the flow of water in the Cauvery to Grand Anicut is managed by the Water Resources Department.
The Upper Anicut built by British irrigation engineer Sir Arthur Cotton, remains a vital structure to regulate water flow in the delta. The Kollidam is the main flood carrier. Whenever Cauvery is in spate, the surplus flow is diverted through Kollidam from Mukkombu.
The old brick masonry structure had survived the onslaught of several floods including the deluges of 1924, 1977 and 2005. On August 22, 2018, nine of the 45 shutters of the structures, along with the supporting piers, collapsed requiring the construction of a new barrage.
