Big water scarcity looms over city

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The scanty monsoon rainfall will in all probability affect city residents in the form of severe water shortage.

The unusually low water level in the Periyar coupled with the incre-asing salinity, may result in a possible cut in the drinking water supply from the Aluva pumping station of the Kerala Water Authority (KWA) to the city and the neighbouring areas.

Unlike previous years, the density of salinity in the Periyar is high as the sea water has already started flowing upstream during high tide. Normally, the reverse thrust of sea water is high during summer days.

According to environmental experts, the intrusion of saline water to the river is high this time as the flow of river water has receded due to the very weak monsoons.

The delay in completing the construction of the temporary sand bunds at Pathalam and Purappillikkavu in the northern and western boundaries is also a major reason for the intrusion of saline water. The construction of bunds should have been completed by mid-November.

“If the works are delayed further, it will result in increased salinity in the river which will affect the water supply to the city and its neighbouring areas”, said a KWA official.

The density of salinity in the water samples collected from Karumallur lift irrigation pump was found to be as high as 2,200 ppm (particles per million), according to KWA sources. The permissible limit of salinity in the raw water in the Periyar is 250 ppm.

However, the salinity of water near the Aluva pumping station was only 20 ppm. The Aluva pump house does not have the facility to treat water with a salinity rate of more than 200 ppm.

“Hence, pumping would have to be stopped if salinity increases beyond that level”, added the official.

Though opening Bhoothathan Kettu and Idamalyar dams is a temporary solution to salinity, this has been ruled out this season due to the decrease in water level following the weak monsoon.