Water supply crisis in Thiruvananthapuram puts spotlight back on delayed Neyyar water supply project

As water supply to Thiruvananthapuram city inches back to normalcy after an unprecedented four-day disruption, the spotlight is back on a major project designed to equip the State capital with a vital, second drinking water source.

The 120 mld (million litres a day) Neyyar water supply project is yet to materialise despite overshooting the original 2021 deadline, even as the Kerala Water Authority (KWA) maintains that the project is still live.

This project envisions a daily supply of 100 mld from the Neyyar reservoir to the Thiruvananthapuram Corporation limits. The remaining 20 mld would be shared among Maranalloor, Malayinkeezhu, Vilavoorkkal and Vilappil panchayats. Plans for the project were drawn up after the water level in the Peppara dam on the Karamana river – the city’s lone water source at present – dipped alarmingly in the 2017 summer.

According to KWA officials, the water utility is now planning to implement the two vital components of the project – a 120 mld water treatment plant (WTP) at Neyyar and the laying of a 1,422 mm transmission main over 23.8 km, from the plant to the city – in a single package.

Earlier, the two works were planned in separate contracts. During the previous LDF government’s term, it was also announced that the project would be commissioned in 2021.

But the Neyyar project hit roadblocks after KWA and the Kerala Infrastructure Investment Fund Board (KIIFB), the funding agency, disagreed on the alignment of the pipeline and land-related disputes disrupted plans for the WTP construction at Neyyar.

The agency RITES, tasked by KIIFB, has proposed an alternative alignment for the pipeline which would minimise the inconvenience to the public and also reduce the distance to about 22 km. “The alignment has been rerouted at Kattakkada and Malayinkeezhu. Now the KWA must file a land acquisition plan,” S. Sethukumar, Technical Member, KWA, told The Hindu.

The inordinate delay that has plagued the project also means that the KWA would have to rework the original cost estimates for the plant as well as the pipeline. Earlier, the State government had issued administrative sanction for constructing the WTP at a cost of ₹60 crore. In 2022, an Erode based firm had bagged the contract for the construction of the pipeline for ₹ 137.70 crore, but this contract was later withdrawn.

The technical specifications of the proposed WTP remain unchanged, KWA officials said.  It will be equipped with plate settler technology (lamella clarifier), a floating water-intake structure, a raw-water pumping main, a submerged centrifugal pump set, an electrical substation building and SCADA system.

A detailed engineering report prepared by the KWA in January 2022 had observed that “the water demand of Thiruvananthapuram city is increasing day by day beyond prediction,” especially during the summer months. Given the limitations on increasing the capacity of the Peppara dam, it is high time the city is provided with an additional water source, and the Neyyar reservoir offered the “only possible solution,” the report said.

“At present, the total draw from Karamana River is 353.50 mld. In drought season the inflow in Karamana River is quite insufficient to meet the demand and the storage of Peppara dam is quite insufficient. Increasing the storage capacity of Peppara is not permitted by the Environment and Forest departments, due to environmental impact/deforestation. Hence it is high time to provide an additional source of supply to the city. The only possible solution is tapping from Neyyar Reservoir,” the report said.