Waterman Rajendra Singh has called for a Central legislation to ensure conservation of the national river Ganga. Only a Central Act giving the river a national status and the importance due to a national symbol would help restore its ecology and ensure its purity and uninterrupted flow, said Mr. Singh, presently spearheading a campaign for protection of the river. The Magsaysay Award winner, also a member of the National Ganga River Basin Authority (NGRBA), talking to The Hindu here on Saturday said efforts to make the political authorities realise the need to stop construction of dams and power projects on the river system, stood frustrated.