Green Infrastructure Decsion Making and Prioritization in Three Diverse US Cities

Communities throughout the U.S. are increasingly making green infrastructure a priority through investments to address growing climate risks and provide other social and environmental benefits. Although vegetated green infrastructure – networks of vegetated areas such as bioswales, rain gardens, and street trees – is widely acknowledged as essential and versatile infrastructure, its implementation often lacks strategic planning to advance equity and promote multifunctionality. Expanding green infrastructure is a key focus for many US cities, as well as the most commonly identified strategy for addressing heat in cities across the US. While many studies have highlighted the need to proactively mitigate and manage climate impacts or examined the potential for green infrastructure to support these efforts, limited research examines the governance structures, processes, and knowledge institutions that influence green infrastructure planning decisions and implementation. The literature that does exist points to weak approaches for achieving or evaluating multifunctionality and equity, but it is still unclear why these challenges persist and how data and tools can improve green infrastructure planning.

This research helps to fill a gap in current knowledge of heat and green infrastructure governance structures by combining modeling techniques and interviews with key local decision-makers to conduct an in-depth study of green infrastructure governance institutions and processes in three US cities that represent contrasting social, environmental, and green infrastructure contexts: Phoenix, Arizona, Boulder, Colorado, and Detroit, Michigan. Our analysis focuses on the actors, information, and formal and informal processes for deciding where to develop green infrastructure in the city, what type of green infrastructure to use, and what benefits to prioritize and monitor, and how implementation is prioritized. The results provide more insight on what governance processes are influencing green infrastructure planning and how these decisions are made. For example, in Phoenix green infrastructure decisions-making spans many departments, even though there are designated practitioners who work solely on green infrastructure investments. This research can inform how decision-support tools for stakeholders may help in targeting green infrastructure investments where multiple functions, such as mitigation of stormwater and heat, are most needed and where they have the greatest potential to improve human health and well-being.