A study in Philadelphia estimated that 196 premature, heat-related fatalities could be avoided over a 40-year period if a 50% Low Impact Development approach (runoff from 50% of impervious surface in the city is managed through green infrastructure) were implemented instead of a more traditional alternative (e.g. 30-ft storage tunnel).
Stratus Consulting. (2009). A Triple Bottom Line Assessment of Traditional and Green Infrastructure Options for Controlling CSO Events in Philadelphia’s Watersheds. Office of Watersheds, City of Philadelphia Water Department, Philadelphia, PA.