Haddam is a town in Middlesex County, Connecticut, United States. The population was 7,157 at the 2000 census. The town was also home to the now decommissioned Connecticut Yankeenuclear reactor. According to the United States Census Bureau, the town has a total area of 46.3 square miles (120km2), of which, 44.0 square miles (114km2) of it is land and 2.3 square miles (6.0km2) of it (5.01%) is water. It is located in the Connecticut River Valley with a majority of the town's eastern border along the Connecticut River. However, part of the border is the Salmon River on the east side, which causes the Connecticut river to divide the community of Haddam Neck from the rest of the town. Haddam is the only town in Connecticut with residents on both sides of the river, however there is no modern bridge or ferry within the town limits.