This study evaluates the performance of green infrastructure (GI) techniques like bioswales and infiltration basins in improving stormwater quality, compared to traditional detention basins. Two adjacent sub-watersheds using these different approaches in a master-planned community are monitored. Preliminary results show the bioswale watershed significantly outperforming the detention basin watershed in removing pollutants like suspended solids, nitrogen, phosphorus, heavy metals, and copper in particular. If implemented more widely, GI could greatly increase stormwater quality while being less expensive and requiring less maintenance than traditional grey infrastructure systems.