Pryor, Mikela Renee (2021-12). EVALUATING THE EFFECTIVENESS OF GREEN STORMWATER INFRASTRUCTURE IN DALLAS, TEXAS: A MODELING AND PUBLIC PERCEPTION STUDY. Master's Thesis.
Thesis
Impervious surfaces such as paved roads, buildings, and parking lots, are a staple feature of urban development, but they prevent infiltration, leading to increased runoff volumes and pollutant loads. Green stormwater infrastructure (GSI) takes a more centralized and connected approach to stormwater management, using engineered soil and vegetation to capture pollutants and decrease runoff velocities. The increased popularity of GSI calls for the need for more research on public perception and watershed-scale impacts of GSI. This study focuses on the City of Dallas, modeling the Five-Mile Creek Watershed surrounding South Oak Cliff High School (SOC) and surveying Oak Cliff residents for perceptions of GSI. A SWMM model was developed to test the effects of rain gardens, bioretention, and rainwater harvesting at the SOC campus on a 291-acre portion of Five Mile Creek on peak runoff, total runoff, and runoff delay for an optimized scenario for runoff reduction. Both single practice and combined practice scenarios were developed for varying rates of adoption. Bioretention was the single most effective GSI practice at the site, considering the suitability criteria. The addition of rainwater harvesting did not greatly aid in runoff volume reduction. The recommended GSI system, based on the success of the scenarios, is a combination of bioretention and rain gardens, with bioretention covering 50% of suitable space and rain gardens covering 20% of suitable space. Furthermore, the results of the online public perception study revealed that respondents care more about water quality and rainwater retention benefits of GSI more than visual attractiveness and recreation. GSI is highly valued among respondents, rainwater harvesting and bioretention cells more so than others. There were positive relationships between flood experience, frequent park usage, and the belief that climate change is problematic for flooding with GSI valuation.
