Capitol Region Watershed District, in partnership with Barr Engineering and several local agencies, developed detailed, calibrated modeling of the Trout Brook Storm Sewer Interceptor watershed, an 8,000-acre urban watershed in St. Paul. The project significantly increased the spatial resolution of existing hydraulic/hydrologic and water quality models, enabling analysis at the scale of individual intersections and storm sewer inlets. A flood mitigation and water quality prioritization analysis used the modeling to identify and rank 20 priority areas. The methodology incorporated flood risk metrics, social vulnerability and water quality improvement opportunities to equitably target investments where they would deliver the greatest combined benefit. CRWD has since completed feasibility studies for eight of the 20 highest-ranked priority areas, including community outreach, stakeholder engagement, development of flood mitigation opportunities and cost-benefit analyses. The presentation emphasizes challenges and lessons learned from working within fully developed urban watersheds where mitigation options are constrained by existing development.