Managing stormwater is tricky business in urban areas, where paved roads, rooftops, and parking lots keep water above ground rather than letting it soak naturally into soils, grasses, and other vegetation. Rain and snow runoff must be caught, channeled, and eventually discarded in “gray” infrastructure, such as curbs, gutters, storm drains, and sewers. All this effort and expense seems so unnecessary, when there are green ways to capture and use the water rather than funnel it away.
But gray infrastructure has been the standard for so long that policy and engineering practice have created tremendous inertia to maintain the status quo. How can it be overcome? Sarah Madden (MCP ’10) took a hard look at the development of Philadelphia’s “Green City, Clean Water” plan to answer this question. She found that a combination of changes in federal policies and the efforts of a determined policy entrepreneur who worked steadily over nearly two decades came together to create the right conditions for the plan to take shape. The lessons Sarah draws from the case study are worth considering for other large cities or even smaller municipalities struggling to find ways to make green infrastructure more palatable in their context. See Sarah’s full thesis,“Choosing Green Over Gray: Philadelphia’s Innovative Stormwater Infrastructure Plan” .