Stormwater Management at Portland State University with the Uncertainty of Climate Change

As climate change persists, precipitation events are expected to become more severe, resulting in increased stormwater runoff. Therefore, the importance of implementing new and upgrading aging stormwater green infrastructure (SGI) is required to reduce its impacts. Stormwater runoff is water typically from rain that is unable to naturally soak into the ground as a result of high amounts of impervious surfaces. When precipitation events occur, stormwater travels across impervious surfaces collecting soils, pet waste, litter, oil, and grease, which can negatively impact water quality in receiving waters. Additionally, stormwater has human health impacts, specifically through flooding and the contamination of drinking water. Portland State University (PSU), located in the middle of downtown Portland, Oregon is a highly urbanized area with stormwater management needs. To reduce runoff, the university has implemented SGI such as bioswales, rainwater reuse systems, and flow-through planters. However, the effectiveness of these systems has not been analyzed. In collaboration with PSU’s Campus Sustainability Office, we are creating a comprehensive inventory of the SGI on campus and determining its effectiveness in reducing stormwater currently and in the future. To do this, we are using the Environmental Protection Agency’s Stormwater Management Model (EPA SWMM) to model PSU’s buildings along with their various facilities. We will use current and future predicted precipitation data to estimate how stormwater runoff at the university will change with increased rainfall. Finally, we will propose recommendations to the university based on these findings for the next 15-20 years