Prior to regulations passed in 2003, flood control was the sole management objective of stormwater basins in Ohio. As a result, many older stormwater basins in urban developments provide little to no water quality benefits; further, they potentially exacerbate the duration of critical discharges in receiving streams, leading to impacts typical of the urban stream syndrome. Simple retrofits to these basins (e.g., adding orifices, weirs, and other flow mitigation features to existing outflow structures) could improve their water quality benefits while concurrently reducing the occurrence of downstream erosion and maintaining flood control capacity. Developed areas in the Cleveland region have many pre-2003 stormwater basins that could be retrofitted to reduce stream impairments, providing a potentially cost-effective management strategy relative to e.g., stream restoration. This presentation will highlight the results of extensive pilot-scale modeling to evaluate the benefits of retrofits to flood control basins in watersheds in Aurora and Mayfield Heights, Ohio. The benefits and challenges of two modeling approaches (i.e., PCSWMM and HydroCAD) will be compared to develop retrofit strategies designed to meet current regulations (i.e., slowly release runoff from a 0.9-in storm event over a 48hr period) while reducing opportunities for downstream erosion in smaller storm events (i.e., reducing the frequency of exceedance of the critical discharge). Findings from this research can inform similar retrofit efforts targeting flood control basins to bolster their water quality benefits and mitigate downstream erosion in a cost-effective manner.