The county lies within the Cape Fear River drainage basin. The Cape Fear River begins in the county near the community of Moncure, at the confluence of the Haw River and the Deep River below Jordan Lake. B. Everett Jordan Lake, a major reservoir and flood-control lake, is located within the New Hope River basin and lies mainly in eastern Chatham County. The lake is owned by the US Army Corps of Engineers and is partially leased by the state of North Carolina as Jordan Lake State Recreation Area.