The sewer and stormwater system in the Pittsburgh region is inadequately sized to capture and treat most "wet weather" events (rain and snowfall), which occur frequently throughout the year. As a result, nearly every time it rains, a sewer overflow occurs, draining a mix of untreated wastewater and stormwater into the county's streams and rivers. This project seeks to inform the multi-billion dollar investment decisions currently facing the region. We will perform a scenario analysis to explore how the system performs under many possible future conditions, and how well certain system improvements hold up across these uncertain futures. The analysis will include hundreds of scenarios using the computer-intensive Stormwater Management Models (SWMM).