A bioretention basin in Melbourne, Australia was studied to see how well it could improve water quality and flow in streams affected by urban development. The basin reduced polluted water entering the stream by 55-65%, lowering peak flows and concentrations of pollutants like sediment and nutrients. While the basin didn't mimic natural flow patterns perfectly, it did help restore some balance to the urban water system. More work at a larger scale is needed for complete restoration of natural flow patterns.