Large-scale watershed models are becoming increasingly available as federal and state agencies have realized their benefits in analyzing flood mitigation related projects. Consequently, the large-scale models, despite their potential utility, remain underutilized. This redundancy can waste valuable resources and overlooks the data and insights already embedded in the HUC8-sized models. To address this, Michael Baker International, in collaboration with St. Tammany Parish, leveraged previously developed HUC8 models produced under the Louisiana Watershed Initiative currently being executed by LA DOTD. Models were utilized in two separate Parish sponsored projects of varying scale. The first is a parish wide Comprehensive Drainage Plan aiming to create easy to use breakout hydraulic models, detailed design plans and a flood mitigation capital improvement plan. The second project consists of reducing the size of a HUC8 model to design and determine flood mitigation benefits of a regional detention project. This initiative highlights the importance of adaptability and innovation in watershed management, ensuring valuable resources are fully utilized while also meeting local engineering needs.