The Croton Dam and its associated aqueduct were constructed to address the pollution of local freshwater sources in Manhattan and the rise in disease, particularly epidemics of yellow fever and cholera. Completed in 1842, the original Croton Dam was the first significant masonry dam in the United States. To enhance the yield of the Croton watershed, a larger dam was constructed three miles downstream of the original dam between 1892 and 1906. The New Croton Dam, which created a 19-mile reservoir, was the tallest dam in the world at the time of its completion.
In addition to the dam itself, the construction project included a steel arch structure over the spillway and another over the Croton River. The spillway bridge was initially constructed by the Baltimore Bridge Company but was replaced in 1975 with a simpler arch design built of Corten steel due to deterioration resulting from exposure to roadway salt and spillway spray. Seismic capacity, deck-bearing details, and anchorage at the arch bases were among the design and structural issues that compounded the bridge’s deterioration, leading to its emergency closure in 2003.
To address the bridge’s condition, an accelerated replacement project was initiated in August, with the new Croton Dam Spillway Bridge completed in 2005 at a cost of $4.6 million. While the new design mimics the original 1905 bridge, it incorporates modern materials and design standards. The Croton River is spanned by a simple steel arch bridge below the dam, which was constructed by John Kenny Jr. to facilitate entry for a private road and now serves as the entrance to the Croton Gorge Park.
The construction of the Croton Dam and the associated aqueduct was a crucial undertaking that helped address pollution and disease in Manhattan. The subsequent construction of the New Croton Dam in the early 20th century expanded the reservoir’s capacity and incorporated innovative design and structural techniques. The replacement of the Croton Dam Spillway Bridge was necessitated by the original bridge’s deterioration, and the use of modern materials and design standards enabled a successful replacement that maintains the appearance of the original bridge.