With the work on a temporary bund across the Periyar yet to be completed, the level of salinity in the river has been on a steady rise, casting a shadow over the supply of drinking water to Kochi and its neighbouring areas.
Kerala Water Authority officials warn that any further delay in completing the bund would lead to disruptions in the operation of the water treatment plant in Aluva. “With the bund completion reaching only the halfway stage, there are chances of high tides from the sea reaching upstream, causing a sharp surge in salinity. There would not have been no such concern had the bund been erected by November,” said a senior KWA official.
As on Saturday, salinity in raw water stood at 15 ppm (parts per million), 35 ppm less from the level recorded 10 days ago. This reduction in salinity, however, was achieved through releasing water from the Boothathankettu dam.
“Managing salinity levels by regulating the water flow from the dam upstream is not a feasible option as a sudden let-out may also lead to a manifold increase in the volume of silt and debris’’, the official said.
Meanwhile, the water level in the river has receded over the past few days though it is sufficient to cater to the three wells drawing water from the river. “As measured by the scale at the plant, the water level has dropped about 20-40 cm than what was recorded during the same period last year,’’ officials said.
Meanwhile, minor irrigation department officials said the bund construction would be completed in January. “We have completed dredging in about 140 metres and the remaining 60 metres will be completed in a couple of weeks. The shortage of sand is the major hindrance in completing the formation as we have to collect sand as far as 250 metres downstream and deposit it on the bund’’, they said.
The shortage of sand is often attributed to indiscriminate sand-mining in the Periyar and even the sand deposited on the bund is often taken away.
