Green Infrastructure Hierarchy Excerpts from Washington: City in the Woods by Glenn Eugster

Green Infrastructure Hierarchy

Excerpts from Washington: City in the Woods by Glenn Eugster 

A foundation of a green infrastructure approach is a vision that all parks, open space and recreation area spaces are, or can be, part of a green space system. Greening the Toronto Port Lands, prepared by Beth Benson and Michael Hough, and others, for the Toronto, Canada Waterfront Regeneration Trust, describes a “Hierarchy of Green Space”.  It suggests an overall long-term vision for green infrastructure that recognizes a variety of values, scale, and design approaches.  A variation of Toronto’s hierarchy, developed for the metropolitan Washington, DC region includes:

Personal space 

• Window boxes
• Private gardens 
• Residential plantings
• Green roofs
• Rainwater gardens

Residential spaces 

• Private land holdings (Stewardship areas-

   private landowner master planning)

• Woodlots
• Residential Commons (“Shared parks in 

   urban blocks”, alley-ways, right-of-ways, community      

   gardens, dedicated green space)

Development spaces 

• Plantings, greenroofs, rainwater gardens, water’s edge 

   promenades, etc.

Community spaces

• Community gardens
• Street trees
• Local government land use efforts
• Arboretums, semi-public and public gardens
• Neighborhood parks
• Public Commons (Squares, major commons  such as the            

   National Mall)

City-Metropolitan Region spaces

• Chicago Wilderness/Chicago Metropolitan Area

• Minneapolis-St. Paul, MN
• NY-CT-NJ Regional Greensward Plan

Regional spaces

• Linear green corridors: Greenways, trail corridors,    

   parkways 

• Linear Corridors (Right-of-ways, Lands under restricted      

   easement)

• Protected stream corridors and riparian areas
• Major parks and recreation areas
• Working land reserves (farm and forest reserves)
• Managed watershed-lands (Charles River, MA; 

      Catskill-NYC Water Supply Lands, Cheney Lake Water Quality    

      Project, South Central Kansas)

• Airsheds (Stuttgart, Germany; Dayton, OH)
• Regional corridors (Appalachian Trail)
• Private working lands (Farms, grazing lands, nurseries,   

   orchards, public and private forests)

Statewide spaces

• Statewide park, recreation, greenway and habitat systems  

   (Florida, Wisconsin, Minnesota, Texas, Maryland)

Multi-state spaces/ mega-region

• Multi-state systems (Chesapeake Bay 

      riparian and submerged aquatic vegetation corridors)

Multi-national spaces/ global regions

• Multi-country systems (Paseo Pantera, 

      “The Path of the Panther”, Central America; Atlantic Flyway      

      Migratory Bird Corridor; Y-2-Y Yellowstone to the Yukon,     

      US-Canada) 

Source:  Washington: City in the Woods; Prepared for the Joint Ventures Conference: Partners in Stewardship, Los Angeles, CA; November 18, 2003; J. Glenn Eugster, Assistant Regional Director, Partnerships Office, National Park Service, National Capital Region, Washington