Wake County is considered to be in a transitional zone between the Piedmont uplands and the coastal plain and, therefore, within the fall zone. The Neuse River and its tributaries drain about 80% of the County, and the southwestern part is drained by tributaries of the Cape Fear River. The stream network generally flows in a southeasterly direction. A 2007 real estate survey has estimated the population of Wake County, North Carolina at 832,970.