It’s hard to imagine the vast tangle of pipes and infrastructure that run beneath the sidewalks where we walk and the roads we drive. It’s also hard to imagine how water flows into these pipes, where it ends up, and what kinds of effects it has on our streams and rivers. This report seeks to explore these questions in Holyoke, Massachusetts where a combined sewer system and an expanse of paving has serious implications for the Connecticut River and beyond. The proposed designs tackle the effects of polluted stormwater runoff and heavy rainfall events through green street designs for Newton, High, and Center Streets.These designs use green infrastructure to fi lter, slow, and retain water to reduce pollutants in stormwater and avoid sewage overfl ows into the river. This green streets plan is one of many efforts taken on by the City of Holyoke to encourage urban revitalization and aims to move the city towards a more sustainable and prosperous future.