Green Alleys in Chicago, USA

Storm water management has paved the way for innovative street design.

Rockwell Avenue after the green alley treatment with modular block-pavers. Photo by City of Chicago

Adapting to one aspect of climate change, such as extreme weather, can encourage new ways of thinking that bring widespread and unexpected benefits.

Reducing flooding

The Green Alleys programme in Chicago aimed to reduce flooding in the city’s 1,900 mile network of alleyways. The Department of Transportation experimented with five new surface designs for the alleys to:

• make them more permeable
• reduce local flooding
• divert rainwater into the ground
• prevent rainwater from overloading the sewer system
• recharge groundwater.

The surface designs use porous asphalt, concrete or permeable pavers laid over a gravel sub-base. The designs use recycled materials and, by completely rethinking the way that the design of the alleys, their appearance has been greatly improved. 

The Green Alleys approach has been adopted throughout the city and is being modified for use in streets and market squares.

Read our case study of Chicago’s green alleys.

Tags: water, cities and towns, neighbourhoods