Water Mill is a census-designated place (CDP) in Suffolk County, New York, USA.
A census-designated place (CDP) is a type of place (a concentration of population) identified by the United States Census Bureau for statistical purposes. Places are delineated for each decennial census as the statistical counterparts of incorporated places such as cities, towns and villages. CDPs are populated areas that lack separate municipal government, but which otherwise physically resemble incorporated places.
The population of Water Mill in New York state was 1,724 at the 2000 census. Water Mill is the correct name as per local government and the United States Postal Service. Its US ZIP Code is 11976.
Water Mill is considering incorporating as a village following the unsuccessful attempt by Dunehampton, New York to incorporate. Dunehampton’s incorporation would have cut Water Mill off from the Atlantic Ocean beaches. Sagaponack, New York incorporated for a similar reason.
As of 2009, Water Mill was listed as the sixth most expensive Small Town in the United States by Business Week. The median home price was $2,238,676.
Water Mill derives its name from a historical claim that the first water mill in the State of New York was built there in year 1644.