Increase in salinity count in the Periyar river water is posing a serious threat to the supply of drinking water to Kochi and its neighbouring areas.
With reports of salinity reaching downstream coming in, officials of the KWA water treatment plant in Aluva are keeping their fingers crossed. The delay in bund construction that should have been completed by November is being cited as the key reason for this phenomenon.
According to the Kerala Water Authority, water level in the river has receded over the past few days though its catchment areas have been receiving good rainfall even after the monsoon season. “At this stage, the level of water is sufficient to cater to the three wells drawing water from the river. But the production levels will be affected if the bund construction is not completed at the earliest, increasing the chances of high-tides from the sea reaching upstream and a sharp surge in salinity,” pointed out a senior official.
The incursion of salinity could be prevented by releasing water from the Bhoothathankettu dam. However, a sudden release of water at this time could lead to a manifold increase in the volume of silt and debris.
“We will be forced to suspend pumping if the salinity levels go beyond 200 PPM (particles per million) in raw water as it will choke the filters and affect operations,” the official pointed out, adding that irrigation in downstream areas have been stopped as the levels touched 300 PPM. Despite the rising salinity levels, the Minor Irrigation Department is yet to commence work on the sand bund. The contract was awarded earlier this month and the work is set to begin soon. “Though the actual time of completion is eight months, we have asked them to complete construction at the earliest,” said a senior official. Around 280-290 mld (million litres per day) of drinking water is being pumped from Aluva and even though the capacity of the plant is around 225 mld the supply has to be stepped up in view of the increasing demand for drinking water.
Of the total supply, about 260 mld is being distributed to meet the drinking water requirements of city residents.
