Leakage in Parbati project tunnel has Sainj valley villagers worried

Significant water leakage has once again been observed from the head race tunnel (HRT) of the 520 MW Parbati Hydroelectric Project Stage-III of National Hydroelectric Power Corporation (NHPC) Ltd near Bihali in the Sainj valley of Kullu district. Local residents are concerned over increase in leakage. The tunnel was leaking even before the project was commissioned in February 2014.

Villagers had raised concerns over water ingress at various points in a 500 metre area between Spangni and Bihali in the 7.98 km tunnel. Even the commissioning of the project was delayed for about seven months for this reason. While water ingress has continued, the authorities concerned had previously assured the residents that leakage posed no threat to nearby habitations and crops.

Local residents, however, contend that the continuous leakage has weakened the hills of Bihali and Spangani, posing a threat to commuters. The seepage in Spangani is a particular concern, with villagers fearing that it can destabilise the hills, endangering many villages in the Sainj valley.

The villagers and the NHPC had come face to face on this matter many times earlier as well and the project management had already spent about Rs 10 crore to stop the leakage but had not been able to do so. While NHPC officials say that the leakage does not endanger the villagers, the latter are not convinced and feel unsafe.

Talada panchayat president Mohar Singh claims that several families are at risk. He alleges, “Construction standards were ignored in the project, leading to rapid water spring emergence from head race tunnel’s seepage.” Villagers Mahendra Singh, Narender Kumar, Roshan Lal and Gambhir Singh criticise the NHPC management for underestimating the gravity of the situation as a major disaster may happen.

Sources say that the tunnel leakage has affected power generation, with the PHEP-III project falling short of its 2024-25 generation target. While the NHPC attributes the reduced production to broader hydropower issues in the state, the 100 MW Sainj Hydro Power Project of Himachal Pradesh Power Corporation Limited on the same river had reported record power generation last year, casting doubts on the NHPC’s claims.

Prakash Chand, general manager, PHEP-III, says that water leakage in tunnels in hilly terrains is a common occurrence. He insists that leakage in the tunnel has neither impacted power generation nor it poses danger to the villagers.