Old Croton Dam

Built between 1837 and 1842, the Old Croton Dam was the first substantial masonry dam in the United States and a core element of New York City's original Croton water-supply system. It was designed under engineer **John B. Jervis**. After the New Croton Dam was completed in 1906, the older dam was submerged beneath the reservoir; the structure still exists in place, though usually underwater. ([en.wikipedia.org](https://en.wikipedia.org/wiki/Old_Croton_Dam)) - **Construction detail:** granite ashlar foundation with a rubble core. ([en.wikipedia.org](https://en.wikipedia.org/wiki/Old_Croton_Dam)) - **Why it remains:** it survives as a nationally recognized historic engineering site rather than an active water-supply work. ([en.wikipedia.org](https://en.wikipedia.org/wiki/Old_Croton_Dam)) - **Further information:** - https://www.parks.ny.gov/parks/oldcrotonaqueduct/details.aspx - https://aqueduct.org/empire-city/croton-dam

South of Yorktown Heights on NY 129, Yorktown, New York, USA