The opening of a shutter of the Pathalam regulator-cum-bridge on March 21 again released dark water downstream of the Periyar at Eloor.
Residents of the area said the shutter, which was opened for around two hours in the morning, released dark water from upstream and it merged with the clearer water downstream of the regulator. “Since sunlight was low, the difference in colour was not visible to many,” said local activist and resident Maheshkumar V.B.
Meanwhile, the Irrigation Department, which has authority over this stretch of the river and is responsible for maintaining minimum water flow in the river (especially now during the lean season and as per the Collector’s latest directive), will submit the details of shutter operation across the three regulators on the river – the Purapallikavu, Manjummel and Pathalam – to the District Collector.
Shutter operation list
It would include a list of how many shutters would be opened at each regulator, said Balu Varghese, assistant executive engineer at the Aluva Irrigation Department.
“The lean flow of the river is 20 cubic metres per second. The rule, as per the order of the National Green Tribunal, is that 15 to 20% of this flow should be released into the river,” said Mr. Varghese. The number of shutters that needed to be opened to enable the flow was being communicated to the Collector, he added. The Department has scales to measure water level in the regulators and this, along with the time for which a shutter is kept open, is used to measure and maintain water levels.