New Croton Dam

The New Croton Dam is a dam forming the New Croton Reservoir along the Croton River in Westchester County, New York.

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The original Croton Dam and the associated aqueduct were constructed in response to pollution of local freshwater sources in Manhattan and an increase in disease, including epidemics of yellow fever and cholera. The dam was built on the Croton River between 1837-1842 and was the first substantial masonry dam in the United States. However, its construction was delayed by a storm that occurred in January 1841, which caused significant downstream damage and loss of life. ^{1 2}

Constructed from square blocks of granite and cement, the 57-foot-high and 670-foot-long gravity dam impounded the Croton River watershed, creating a reservoir with a capacity of 500 million gallons. ² Water from the reservoir was transported to New York City through the Croton Aqueduct, which was completed on October 14, 1842. A larger aqueduct was built between 1885 and July 1890 to accommodate the growing population of New York City, which tripled between 1840 and 1870.

To increase the yield of the Croton watershed, a larger dam was constructed on the Croton River three miles downstream of the original dam on the property of A.B. Cornell. ² The New Croton Dam, designed by Alphonse Fteley with 480 feet of compacted earth topped with granite blocks, began construction in September 1892. ^{2 4} However, cracks in the core wall led to a change in the dam’s design, and the final structure was a complete masonry dam constructed of granite blocks.

The New Croton Dam, completed in January 1906, was the tallest dam in the world at the time of its completion, standing at 297 feet high and 2,188 feet long. ^{2 3} It further impounded the Croton River watershed, creating a reservoir 19 miles long with a capacity of 19 billion gallons of water. The old Croton Dam was entirely submerged by the new structure. The construction of the new dam also included a steel arch structure over the spillway and another over the Croton River.

The Croton Water Supply System, which included the original and new dams and the aqueduct, was designated a National Historic Civil Engineering Landmark by the American Society of Civil Engineers on October 16, 1975. The Croton Aqueduct was added to the National Register of Historic Places in 1974 and designated a National Historic Landmark in 1992. The New Croton Dam remains the largest structure of pure masonry in the world. ⁴

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Details

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Sources

1. Fyfe, Joan J. “Preserve the Past – Enlighten the Future.” Yorktown Historical Society, Fall 2004.
2. “Croton Water Supply System.” ASCE Metropolitan Section.
3. Jackson, Donald C. Great American Bridges and Dams. John Wiley & Sons, 1988, p. 128.
4. Stott, Peter. “New Croton Dam (Cornell Dam).” New York State Historic Trust, 14 Dec. 1972.