Threat of increased salinity in the Periyar
Work on the temporary bund at Purappalikavu to check salinity intrusion into the Periyar river has begun amidst fears that any delay in its completion might affect the water supply system in the district.
The construction of the 270-m-long temporary bund by the Minor Irrigation Department began last week. But sources in the department admitted that work has not gathered pace due to paucity of funds and non-availability of sand for construction work. Huge quantities of sand is collected from the downstream of the river to set up the bund every year. The estimated cost of construction of the temporary bund is around Rs.25 lakh.
Kerala Water Authority officials said that the threat of salinity intrusion loomed large over the water supply system. The permissible limit of salinity in raw water in the Periyar is 250 ppm (parts per million). Salinity levels had reached a maximum, 400 ppm, last year.
Farmers residing at the Kunnukara panchayat said that the speedy completion of the bund would prevent intrusion of saline water into their agricultural land. Nearly 170 families in Cheriyatheykanam and Karaykathuruthu depend on Periyar waters for their farming activities.
K.A. Sathyan, a farmer, said that saline water intrusion could be checked effectively with the commissioning of the proposed permanent regulator-cum-bridge at Purappalikavu using assistance from the NABARD. He said that seven families had agreed to provide their land for the project in view of the change in the alignment of the regulator-cum-bridge. The government had also decided to drop its earlier plan to construct the regulator-cum-bridge 750 metres upstream from the existing temporary bund, he said.
C.M. Joy, president of the Association for Environment Protection, Aluva, said that the saline water would not recede if the discharge level failed to increase in the coming days. The saline water incursion would become irreversible unless rectified immediately, he said.
Officials said an immediate solution to the problem would be to let out more water from the Edamalayar dam from where the tailrace water would flow to Bhoothathanketu dam and was let out to the Periyar River.