The NYC Watershed Art Project thanks our sponsor Hart Howerton for supporting our efforts to create a lasting portrait of this beautiful watershed!
Continuing with the story of Westchester County’s New Croton Dam, here is more from the Town of Croton’s history page:
“The Quarry:
James Coleman organized the Croton Quarry Company after he bought the Millstone Hill Quarry near Hunterbrook, which provided the dark gabbro stone for the inside portions of the walls and excavations. A railroad was built on leased land, 17 miles of track to Peekskill and Quarry Acres. All along the hills of the dam and on the site, a miniature railroad was constructed that carried on it open cars with materials removed from the banks or stone and brick for construction.
The Work:
After the machinery, plant and quarters for their men had been set up by the contractors, they began the work of excavating for the great dam. Work began September 16, 1892 . The riverbed had to be bared and a pit had to be excavated to 130 feet deep. To do this a canal 1000 feet long and 200 feet wide was cut into the rocky hillside across the north end of the dam. This was a crescent – shaped diversion, which had been blasted out of the solid rock of the hillside north of the valley. Its upper and lower ends joined the old riverbed. The river was confined by means of a masonry wall 600 feet along the south bank. This was then continued at each end by the dam extending across the old channel. One of these dams was 30 feet high and 110 feet wide built of rolled earth, with a vertical center wall of heavy timber piles driven 20 feet into the ground.
A similar dam is built across the old riverbed at the lower end of the canal. The space enclosed between them was pumped dry by powerful steam engines. This diversion alone cost many thousands of dollars. To be safe, for eight years during which the great dam would be under construction, the trench was made as strong and as heavy as any permanent structures. Cofferdam and cableways are erected and construction continued. At the downstream side, the masonry was built solid against the rock face and then stepped back to lines in steps 24 inches to 30 inches high, to the level above the back-filling where the cut stone-facing of the dam was begun. In 1896 the central masonry dam was extended 110 feet. Then when cracks appeared in 1901, the masonry dam was extended to the south side of the valley.
Two-ton rocks were hauled down by cables and placed on the main dam. Derricks on the main wall passed rock and mortar to the locations, 36 masons laid an average of 3240 cu. yards of masonry a month. Work continued day and night, summer and winter, except when it was 20 degrees below zero. In winter, the rocks were steamed and salt was added to the mortar to prevent freezing.”