G. Mahadevan

Project may be included in JBIC-sponsored scheme

Standby to burst-prone stretch up to Peroorkada

Water supply will not be affected even if pipe bursts

THIRUVANANTHAPURAM: The Kerala Water Authority (KWA) is planning to lay a pumping main pipeline from Karakulam to Peroorkada as a standby to the burst-prone portion of the ‘pre-stressed concrete’ main line on this stretch.

The authority plans to get this project included in the Japan Bank of International Corporation (JBIC) scheme. Already included in the scheme are replacement of portions of the main pipelines bringing water from Aruvikkara to various reservoirs in the city.

Once the parallel line — parallel to the main line coming from the 84-mld (million litres a day) treatment plant at Chithirakkunnu — is laid, the KWA will provide ‘interconnections’ at its point of origin and at Peroorkada so that if the existing line bursts, water supply will not be disrupted. However, laying a parallel line for a couple of kilometres may prove to be an incomplete solution for creation of a backup for city’s water supply system.

A more practical and long-term, but costlier, solution will be to lay a parallel line from Aruvikkara to Peroorkada and provide interconnections to the pumping main lines originating from the 72-mld treatment plant and the one at Chithirakkunnu. This way, the parallel line can serve as a standby for both arterial pipelines. Under the JBIC scheme, about 7 km of pipes will be replaced. Should the KWA choose to lay a parallel main from Aruvikkara, 9 km of pipe will have to be laid.

The cost of replacement and laying of short stretches of parallel mains will be about Rs.20 crore. Laying a parallel main from Aruvikkara will cost Rs. 10 crore more. The additional cost will go as ‘tar cutting’ costs to the Public Works Department. “If a parallel main is to be laid from Aruvikkara to Peroorkada, it will have to be right under the main road; it is doubtful if we can find land by the sides of the road,” a KWA engineer said. KWA Managing Director Suresh Babu said the current thinking was to go in for a ductile iron parallel main. These pipes last longer and can withstand greater water pressure.