Waim?nalo is a census-designated place (CDP) in the City & County of Honolulu, in the District of Ko?olaupoko on the island of O?ahu, Hawaii, United States. This small windward community is located near the eastern end of the island. In the Hawaiian language Waim?nalo means "potable water"; it is so named for the many brackish ponds in the area that were used for irrigation. As of the 2010 Census, the CDP had a population of 5,451. According to the United States Census Bureau, the CDP has a total area of 4.4 square miles (11.3 km2), all of it land.