Colchester Township is located in McDonough County, Illinois. As of the 2010 census, its population was 1,837 and it contained 896 housing units.[2]
Geography
According to the 2010 census, the township has a total area of 18.19 square miles (47.1 km2), of which 18.07 square miles (46.8 km2) (or 99.34%) is land and 0.13 square miles (0.34 km2) (or 0.71%) is water.[2]