NHPC's clarification | 25 Jun, 2020

It has been observed that Subansin Lower Hydroelectric Project is in the news for last few days. Local media have been highlighting some recent happenings – landslides in the project site, washing away of coffer dam and overflow of river over the main dam and mentioned that the downstream people are in panic for any adverse effects like high flood, erosions etc.

As per planning, the diversion tunnels are designed to divert river water up to 4550 cum/sec which is I in 25 years non-monsoon flood of 7 months from October to April, During monsoon period, whenever flow of water is more than 4550 cum/sec, excess water flows over the dam during the construction period.

NHPC wishes to clarify that washing away of downstream coffer dam and river flowing above the dam is a normal event during the monsoon seasons.

Photographs of river in June 2018, June 2019 and June 2020 show similarly. We assure the people living in the downstream areas that this dam is absolutely safe and there is no need to panic.

Slope failure in diversion channel along the left bank road is due to prolonged flow of water in diversion structures and is in no way related to the safety of the dam. The slopes shall be repaired after monsoons during the balance construction period after which the diversion tunnels shall be plugged.

Lucas Guria,

General Manager (HR-PR)