Princeton University
IN-15: Stormwater Modeling

A campus-wide hydrologic stormwater model was prepared for Princeton’s main campus in 2006. The model was prepared to evaluate the baseline stormwater conditions (2006) and to model development scenarios (and mitigation strategies) anticipated by the 2016 Campus Plan. The hydrologic model was prepared using HydroCAD (a software that utilizes the TR-20 methodology). As the University implemented the 2016 Campus Plan projects between 2006 and 2016, the model was updated by the University’s stormwater consultant to document the stormwater improvements projects. In 2016, the University embarked on a new Campus Plan (the 2026 Campus Plan). The main campus hydrologic model was expanded to include the West Windsor (Lake) campus as well. A spreadsheet-based water quality model was also prepared for the main campus and West Windsor (Lake) campus. The model continues to be used to review planning scenarios and mitigation strategies, as well as document actual progress through completed projects.

In 2006, the University established project-specific stormwater performance standards to supplement the local/state stormwater regulations with a greater focus on water quality and water balance. The project-specific stormwater standards promoted the use of LID and green infrastructure practices for all projects. The performance standards require the retainage of the 90th percentile rainfall depth (1.25”) using landscape-based approaches wherever possible. Over the past decade, the University has redeveloped approximately 100-acres of land, aligning with the stormwater performance goal to retain the 90th percentile rainfall depth.