Toward the Implementation of Green Infrastructure in Japan through the Examination of City of Portland’s Green Infrastructure Projects

The purpose of this case study research is to examine City of Portland's green infrastructure projects towards the implementation of green infrastructure in Japan.Interviews with Portland's Bureau of Environmental Services followed by discussion and site visits were conducted in May, 2014.In this paper, firstly, green infrastructure's current situation, the Bureau's organizational structure to implement green infrastructure, and the characteristics, typologies, and chronological histories of green infrastructure projects in Portland are summarized.Secondly, 10 selected City of Portland's green infrastructure projects are examined in detail and categorized based on project types, project information, managed stormwater areas, implemented stormwater tools as well as environmental benefits from the projects.Based on the discussion on the challenges of green infrastructure in Japan and the findings from the case studies, the paper concludes with suggestions to overcome the obstacle s of green infrastructure implementation in Japan, given existing stormwater storage and infiltration technologies.