What do planners and planning have to contribute to the process of implementing green infrastructure (GI) projects? More importantly, what exactly constitutes green infrastructure? And where has it been implemented successfully? The Planners Advisory Service (PAS) Report Green infrastructure: A Landscape Approach (2013; APA Planning Advisory Service; 160 pp.; $60) takes a closer look at the ways in which large-scale GI efforts have been implemented nationwide.
First things first "green" infrastructure is green in relationship to "gray" infrastructure such as stormwater sewers and impervious sidewalks. At least that's one definition. Another is a set of coordinated greenspaces that provide ecosystem services across a large area. And in effect, some things (e.g., park systems) may be both, depending on how it's developed. Its real world forms vary significantly, from regional greenways and tree planting efforts to smaller, site specific green roofs and rain gardens.
Second, while some types of green infrastructure may be developed without using GI as a concept (urban parks, for example), the systemwide benefits that GI can produce do not generally happen without large-scale collaborations across disciplines. As a result, while planners may have a relatively independent role to play in terms of GI-friendly (or required) policy, they will need to play nice with other professionals (landscape architects, engineers) along with community leaders and the public at-large in order to be successful.
Green Infrastructure isn't a technical manual in the sense of construction; it contains a conceptual approach that mentions specifics but doesn't go so far as to lose sight of the crux of the book, which is to make plans and not necessarily blueprints for GI. The bulk of the report (nearly 100 out of 157) consists of case studies from across the country. The studies range in scale from big to small cities (Philadelphia and Lancaster, Penn., respectively) and onto regional-scale efforts (Cleveland, North Texas).
Perhaps the most impressive of the case studies is Lenexa, Kansas, a suburb of Kansas City, where the city is creating a series of parks with regional stormwater lakes (two have been built so far) and regulations specify a 25' minimum "outer zone" beyond the floodplain of certain critical streams. The case studies are authored by local authors knowledgable about their given topics.
As is usual for PAS Reports, Green Infrastructure: A Landscape Approach provides a solid overview of the topic, and bridges theory with practice by providing a series of illustrative case studies. An appendix also includes a model regulatory framework for GI. Overall, the text could use some more web links to more information, which might make up for the lack of technical detail. However, doing so would also date the text, and the lack of web links that doesn't necessarily diminish its value overall.