The majestic River Ganga is a sacred environment which nurtures more than 650 million people in her large watershed. The Ganga has proved resilient despite the multiple, enormous, environmental stressors placed on her. The Laurentian Great Lakes have also faced severe environmental degradation and the lessons learned there over the past 50 years can provide guidance for the remediation and restoration of the Ganga. One of the more important lessons is defining Beneficial Use Impairments to focus remediation efforts in degraded Areas of Concern. This paper provides a case study of one such impairment, Eutrophication or Undesirable Algae, and shows how it can be applied as part of a broader Ecosystem Approach towards the identification and selection of Ganga Areas of Concern. The 10 proposed Ganga Areas of Concern are intended to provide guidance to all stakeholders on how and where to focus remediation efforts on the Ganga, and similar ecosystems throughout the world.