Green stormwater infrastructure and water resources in the urban built environment: opportunities and barriers in a coupled natural-human system.

Abstract:

Green storm water infrastructure (GSI) is being used to assist in solving various aspects of the three problems of water (too much, not enough, and not the right kind) in cities. The implementation of GSI has been viewed as a way to reduce flooding risk, increase water supply, or improve water quality both directly and indirectly in previous studies. Here we discuss the implementation of GSI in a specific natural and social context Tucson, AZ. This city has a semi-arid climate with two precipitation seasons, winter and summer monsoon. As a semi-arid city, it is restricted in local water resources creating the need to supplement local groundwater utilization with Colorado River water to supply municipal needs. Recently GSI has been looked to as a solution for the water resources challenges of the city along with flood risk. These motivations differ from more humid regions where flooding and water quality problems are generally the primary motivations for GSI implementation. These differences stem from several natural and social system factors. In Tucson, increases in runoff at the lot scale can be over 100% compared to surrounding rangelands. However, at the neighborhood and larger watershed scale, these increases are generally smaller. This implementation has occurred despite financial, policy and educational barriers to GSI adoption by individuals, municipalities and others. The strategies developed in Tucson also differ from those that have been implemented in other metro areas. We also see in our coupled human-natural system feed backs where previous success at GSI implementation has led to changes in the natural environment that have then induced further changes in human behavior at the individual and group level.