This paper compares ongoing research results on hydrologic performance to common design and crediting criteria, and recommends a change in direction from a static to a dynamic perspective to fully credit the performance of green infrastructure. Examples used in this article are primarily stormwater control measures built for research on the campus of Villanova University [1,2]. Evidence is presented demonstrating that the common practice of crediting water volume based on soil and surface storage underestimates the performance potential, and suggests that the profession move to a more dynamic approach that incorporates exfiltration and evapotranspiration. The framework for a dynamic approach is discussed, with a view to broaden our design focus by including climate, configuration and the soil surroundings. The substance of this work was presented as a keynote speech at the 2016 international Low Impact Development Conference in Beijing China [3].
