Waimea is a landlocked census-designated place in Hawaii County, Hawaii, United States. The population was 7,028 at the 2000 census and 9,212 at the 2010 census. Since each U.S. state cannot have more than one post office of the same name, and there is a post office in Waimea, Kauai County, the official U.S. Post Office designation for Waimea is Kamuela, although this name is only used by the post office, not by locals or the local government. The name Waimea means reddish water.