Haridwar: Noted environmentalist G D Agrawal has begun an indefinite fast over the degradation of Ganga river here.

Agrawal, who has undertaking several fasts in the past over the issue, began his fast on Thursday at Matri Sadan ashram.

Construction of dams on river Ganga, shifting its water through canals, draining of effluents into the river are still continuing despite an assurance from the Prime Minister in this regard, he said.

In 2008, the former IIT-Kanpur professor had sat on the fast in Uttarkashi district on the bank of Bhagirathi river, forcing the Uttarakhand government and the Centre to scrap three hydro-power projects.