What is the amount of impervious surface I am allowed?
There are impervious surface limits on parcels that are within the watershed protection overlay districts of Durham. To find out if your property is in the watershed protection overlay district, you can use the Development Tracker: http://gisweb2.durhamnc.gov/durhammaps/developmenttracker/index.html. Please take a look at the related articles to find out about how to use the Development Tracker and the Planning Identify tool.
If your property is in a watershed protection overlay district, the Watershed Protection box in the Planning Identify tool will list the name and the abbreviation of the watershed protection overlay district. Information about the watershed protection overlay districts and the allowed percentage of impervious surface can be found in Article 8.7 of the Unified Development Ordinance: http://www.codepublishing.com/NC/Durham/#!/8.7.html#8.7.