The impervious surfaces of built landscapes create stormwater runoff that causes water quantity and quality problems downstream, upsetting natural hydrology and harming aquatic ecosystems. Green stormwater infrastructure (GSI) includes practices that reduce the amount of stormwater runoff and the pollutants it carries utilizing plants, soils, and other materials to capture, store, reuse, infiltrate, evapotranspire, and filter stormwater. GSI helps to restore developed landscapes, mimicking natural hydrologic processes and providing important water treatment functions as well as beneficial green spaces in urban areas. However, there are many challenges associated with the implementation and maintenance of GSI in our communities and cultures. This research explores the human side of implementing GSI, investigating current maintenance capacities in rural and urban settings, and exploring multifunctional benefits of GSI to provide both biophysical and cultural ecosystem services (CES). Research goals include characterizing the current state of GSI implementation and maintenance in municipalities in the State of Vermont (USA) and eliciting lessons that can inform GSI design practices and policies. Multifunctional GSI design objectives that provide and enhance CES are described, revealing opportunities to instill values and a sense of stewardship for the health wellbeing of people and ecosystems. The first chapter provides relevant topical background to set the stage for the latter two chapters. The second chapter analyzes results from a survey of municipal officials in Vermont that occurred as part of NSF-EPSCoR-funded Basin Resilience to Extreme Events project research on stormwater management. The survey included questions about GSI and maintenance practices in place and perceptions of visual appeal and ability to maintain bioretention systems shown in landscape visualizations. Results show that visual appeal and perceived maintainability of vegetated bioretention practices do not appear to be significant barriers to adoption and operation, but stormwater policy and funding are shown to be both significant barriers and solutions to implementing and maintaining GSI in Vermont municipalities. Additionally, urban and rural towns provide very different contexts for implementing and maintaining GSI in Vermont and characteristics of development patterns and maintenance capacity should be considered in policy, regulations, outreach, and education. The third chapter offers a literature review, guided by a CES framework, of design elements that can be included in GSI to create multifunctional urban green spaces. CES categories of aesthetic, recreation, education, sense of place, social capital, and stewardship benefits framed a set of design elements, principles, practices, and documented benefits to guide multifunctional design of GSI. Findings include the importance of participatory processes to elicit diverse landscape values, visible water pathways, biodiversity, spaces for creative use, accessibility, interaction with water, interpretive signage, and artful and biophilic design features to enhance feelings of preference, pleasure, relaxation, learning, connection, and inclusion. The health and wellbeing of water and people must be integrated into the design of GSI for cities to be ecologically functional and culturally meaningful to their populations.

No description available.

Urban stormwater runoff is both an environmental threat and a valuable water resource. This dissertation explores the use of two stormwater management strategies, namely green stormwater infrastructure and stormwater real-time control (RTC), for capturing and treating urban stormwater runoff. Chapter 2 focuses on clean bed filtration theory and its application to fecal indicator bacteria removal in experimental laboratory-scale biofilters. This analysis is a significant step forward in our understanding of how physicochemical theories can be melded with hydrology, engineering design, and ecology to improve the water quality benefits of green infrastructure. Chapter 3 focuses on the novel application of unsteady transit time distribution (TTD) theory to solute transport in a field-scale biofilter. TTD theory closely reproduces experimental bromide breakthrough concentrations, provided that lateral exchange with the surrounding soil is accounted for. TTD theory also provides insight into how changing distributions of water age in biofilter storage and outflow affect key stormwater management endpoints, such as biofilter pollutant treatment credit. Chapter 4 focuses on stormwater RTC and its potential for improving runoff capture and water supply in areas with Mediterranean climates. We find that the addition of RTC increases the percent of runoff captured, but does not increase the percent of water demand satisfied. Our results suggest that stormwater RTC systems need to be implemented in conjunction with context-specific solutions (such as spreading basins for groundwater recharge) to reliably augment urban water supply in areas with uneven precipitation. Through a combination of modeling and experimental studies at a range of scales, this dissertation lays the foundation for future integration of TTD theory with RTC to improve regional stormwater management. / Doctor of Philosophy / Urban stormwater runoff contains a variety of pollutants. Conventional storm drain systems are designed to move stormwater as quickly as possible away from cities, delivering polluted runoff to local streams, rivers, and the coastal ocean – and discarding a valuable freshwater resource. By contrast, green stormwater infrastructure captures and retains stormwater as close as possible to where the rain falls. Green stormwater infrastructure can also help remove pollutants from stormwater through physical, chemical, and biological treatment processes. This dissertation describes two modeling approaches for understanding and predicting pollutant removal processes in green stormwater infrastructure (Chapters 2 and 3). Chapter 4 explores the implementation of smart stormwater systems, which use automated controllers and sensors to adaptively address stormwater management challenges. Through a combination of modeling and experimental studies at a range of scales, this dissertation lays the foundation for future improvements to regional stormwater management.

No description available.