Old Harbor is a city in Kodiak Island Borough, Alaska, United States. At the 2010 census the population was 218, down from 237 in 2000. Ac…Old Harbor is a city in Kodiak Island Borough, Alaska, United States. At the 2010 census the population was 218, down from 237 in 2000. According to the United States Census Bureau, the city has a total area of 26.5 square miles, of which 20.5 square miles is land and 6.0 square miles, or 22.59%, is water.