Woodhaven is a city in Wayne County, Michigan, United States. As of the 2010 census, the city had a population of 12,875. It is part of a collect…Woodhaven is a city in Wayne County, Michigan, United States. As of the 2010 census, the city had a population of 12,875. It is part of a collection of communities known as Downriver. According to the United States Census Bureau, the city has a total area of 6.45 square miles, of which 6.39 square miles is land and 0.06 square miles is water.