Big Branch is a long tributary of Crabtree Creek in Wake County, North Carolina, and is classed as a 2nd order stream on the EPA waters geoviewer site.
Big Branch rises in northern Raleigh, North Carolina, then flows south to meet Crabtree Creek across from Kiwanis Park. It is a developed watershed with only 7% of the watershed considered to be forested.
Big Branch drains of area. The upper part of the watershed is underlaid by Falls Leucogneiss. The middle and lower watershed is underlaid by Raleigh Gneiss geology. The watershed receives an average of 46.5 in/year of precipitation and has a wetness index of 415.15.