Increasing salinity and decreased width of the Narmada are among the adverse effects of Sardar Sarovar Dam, Congress lawmaker Ahmed Patel told the Rajya Sabha on Wednesday.

Patel, a Member of Parliament (MP) from Gujarat, talked about the increasing salinity of the river water as sea water is making its way upstream, negatively impacting agriculture. He also said that the width of the river has come down from 1.5 kilometres to 400 metres after the construction of the dam. He also drew the attention of the House to the scarcity of water in the 45-kilometre stretch between the dam and the estuary of the river.

As a solution, Patel asked for regular release of water from the dam. The Congress MP also urged the House to see to it that a protection wall is built on the banks of the river to prevent soil erosion, and asked the government to form an expert committee to look into the issue.

According to Himanshu Thakkar of South Asia Dams, Rivers and People, a non-governmental organisation that studies the impact of hydropower projects, the increased salinity of the Narmada will have a major impact on not only the surface water but also ground water. “Once polluted, ground water cannot be restored,” said Thakkar, adding that around 10,000 families dependent on fishing in the area are also affected by the dam.