Site of Old Croton Dam

Site of Old Croton Dam is a historic dam site located at Yorktown, Westchester County, New York. The dam was built between 1837 and 1842 and was the first substantial masonry dam in the United States. Construction of the dam was delayed by a January 1841 storm that washed away most of the dam.A gravity dam constructed with a rubble core and granite ashlar foundation, it was 57ft high and 670ft long. The dam formed a reservoir several miles long, extending northeast along the path of the Croton River. Water flowed to New York City through the Old Croton Aqueduct, which starts just upstream of the dam and carries water down the Croton River valley toward the Hudson, and roughly follows the Hudson south. The dam and aqueduct constitute a major part of the original New York City water supply system. When the New Croton Dam was completed in 1906, the old dam was submerged, but the aqueduct continued to operate until 1955. When the reservoir created by the New Croton Dam is full, the old dam is submerged to 34ft.It was added to the National Register of Historic Places in 1973.