In a natural watershed (with 0% impervious surface), ground water infiltration is 50%, but as development increases, impervious surface penetration decreases ranging from 42% infiltration—in low density development to areas—down to 15% infiltration in urban watersheds.
A great refresher video, provided here by The Watershed Institute, as how human activity and development impacts stormwater run-off: https://youtu.be/qmbw5qO9v74
Also, did you know that similar helpful environmental resources and planning tools are nicely organized and provided by ANJEC, the Association of New Jersey Environmental Commissions available at: http://www.anjec.org/ToolsResources.htm
Weather events, major and minor, are cause for concern urging needed action now. Further focusing and re-thinking the high value and need to integrate non-structural best management practices to new and existing impervious land surfaces is key. From PSU: The Role of Trees and Forests in Healthy Watersheds