Sustainability assessment of green infrastructure practices for stormwater management: A comparative emergy analysis

Stormwater management is a great challenge for cities. Cities are looking to green infrastructure stormwater management practices (GISWMPs) to find cost-effective, and sustainable solutions. Much has been said in relation to stormwater runoff quantity and quality treatment through GISWMPs, however many questions remain unresolved in relation to their resource consumption over time. The main goal of this thesis is to determine the relative sustainability of common GISWMPs by accounting for the environmental and economic inputs during their life spans. Secondary goals are to indicate how emergy indicators might inform policy makers; and to explore the impacts that emergy analysis might have on Rust Belt Cities. Emergy analysis is an environmental accounting method for all the energy that was used previously in the work of making a maintaining a product or service and is expressed in units of solar energy. Raingardens, bioswales, new tree planting, extensive green roofs, constructed wetlands and permeable pavement were analyzed considering the valuation of three ecosystem services; education incomes, biodiversity protection and stormwater treatment. The results indicate that GI practices are more sustainable than gray infrastructure, that the construction stage represents high environmental impacts for all practices and also that during the operation stage raingarden, bioswale and green roofs are less resource intensive than tree planting and standard constructed subsurface wetlands. Porous pavement is the least sustainable strategy achieving emergy indexes closer to gray infrastructure.;Key words: stormwater management, green infrastructure, ecosystem services, emergy...