[a] and was formed by impounding the middle of the West Branch of the Croton River, submerging the village of Boyds Corner.

The construction of the Boyd's Corner Reservoir was overseen by William M. Tweed, known as “Boss” Tweed, Commissioner of the NYC Department of Public Works, who ordered the construction of an earthen embankment to strengthen the structure.

[3][4] In 1874, according to the Putnam County Courier, Theodore Cole of Coles Mills sued New York City for $10,000 in damages due to the Boyds Corner Reservoir dam causing the stoppage of water from the Croton River to his four mills.

After settling at Kensico, the water flows through two aqueducts to the Hillview Reservoir in Yonkers, where it enters the City's distribution system.

Any water in excess of New York City's needs at the West Branch Reservoir is diverted over a spillway back into the West Branch of the Croton River, whence it becomes part of the City's Croton Watershed.