Evaluating the Risk-Based Performance of Bioinfiltration Facilities under Climate Change Scenarios

Many communities throughout the world are utilizing green infrastructure practices to mitigate the projected impacts of climate change. While some areas of the world are anticipating droughts, other areas are preparing for an increased flood risk, due to changes in precipitation volume and intensity. Cities rely on practices such as bioinfiltration to sustainably capture stormwater runoff and provide resilience against climate change. As cities aim to increase resilience and decrease climate-change-associated risks, a greater understanding of these risks is needed. A risk-based approach was used to evaluate bioinfiltration design and performance. Climate projections from the Couple Model Intercomparison Project Phase 5 were used to create near-term (2020-2049) and long-term (2050-2079) climate datasets for Philadelphia, Pennsylvania, using two representative concentration pathways (RCPs 2.6 and 8.5). Both near-term and long-term climate models demonstrated increased precipitation and daily temperatures, similar to other areas in the U.S. Northeast, Midwest, Great Plains, and Alaska. Climate data were used to model bioinfiltration practices using continuous simulation hydrologic models. Overflow events and cumulative risk increased from bioinfiltration sites when compared to the baseline scenario (1970-1999). This study demonstrates how to apply a risk-based approach to bioinfiltration design using climate projections and provides recommendations to increase resilience in bioinfiltration design.