In India of the 233 Class I Cities Situated In 14 Major River Basins, Only 24% Are Having Proper Sewerage Systems and Class Ii Cities Don’T Have any Sewerage System For Collection of Domestic Wastewater. Just Collection of the Sewage Is Not Enough; Further Treatment Facility to Purify the Sewage Is Also a Necessity. So, All These City Wastewaters Are Naturally Taken to the Nearby Rivers and Lakes By Nallas and Odhas (Streams - Natural Drains). These Natural Drains In the Cities Are Serving As Sewerage Lines. the Studies Published By Cpcb In 2013 Reveal the Pathetic Condition and Inadequacy of Pollution Treatment Infrastructure In India. Then Planning Commission Has Suggested Developing “Treatment Zones” In City Drains. It’S a Very Innovative Approach Acknowledged By Government of India Which Needs to Be Strengthened Further By Very Scientific Implementations By Scientists Who Have Mastered the Art of Eco-Treatment of Polluted Waters. from the Case Studies of Udaipur’S Ecological Restoration of Ahar River and Allahabad’S Ecological Treatment Rasoolabad Stream Complex, It Can Be Said That Such Types of Eco Technological In-Situ Treatment –Green Bridge– System Deliver More Than Expectations In the Form of Extended Social and Ecological Capitals. the Capital and Operational Costs of Ecological Treatment Processes Are Comparatively Less Than Conventional Engineering Approaches.