All hydroelectric projects on the Ganga could be asked to reduce their power generation — possibly up to 50 per cent of capacity — in an effort to provide a clean and continuous flow of the river's water, if a proposal by Environment Minister Jayanthi Natarajan is found to be legally viable.

“We cannot shut down existing projects, but we are exploring the legality of reducing the capacity of operational hydroelectric plants,” she told The Hindu on Tuesday. “A clean Ganga is my top priority at present… we need to get extremely proactive.”

If the proposal, which Ms. Natarajan plans to take to the Prime Minister, is implemented, the power generation of 17 operational projects could be affected. Apart from these, 14 projects are currently under construction, while 39 more are in the pipeline.

State governments and industry players, already facing power shortages, are likely to vociferously protest any such move, but the Union Environment Ministry is scanning the Environment Protection Act (EPA), to find a way to overrule states in the interests of a free-flowing river. “We are seeing if a way can be found under the EPA to impose conditions post-facto [on these projects], given that the Ganga is national river, and free flow is an environmental issue,” said Ms. Natarajan.

She has already put an effective moratorium on fresh environment clearances for any new hydroelectric projects on the river, in the wake of an increasingly strident campaign for “nirmal dhara” and “aviral dhara” (clean and free flow) by environmental activists and Hindu religious leaders. Last month, activists stepped up their demands through indefinite fasts and resignation threats of three members of the National Ganga River Basin Authority (NGRBA).

With complaints that the NGRBA is helpless, despite being headed by the Prime Minister, Ms. Natarajan also gave a proposal to set up a new Ganga Commission, which could effectively monitor activities on the ground. “It would be like a beefed-up CPCB [Central Pollution Control Board] exclusively for the 40-odd Ganga districts,” she said.

Meanwhile, CPCB has been told to provide zero-discharge of industrial effluents into the river by October this year. However, the Environment Minister was quick to point out that massive hydro projects and polluting industries aren't the only culprits.

“Vast amounts of water get diverted for agriculture through irrigation canals, but no one talks of that when they talk of the free flow of the river,” she pointed out. “In terms of pollution, 75 per cent of the effluents are domestic, rather than industrial. We have funded sewerage treatment plants, but unless local governments use them and set up sewerage networks, that will be of little use.”