A dam was built at the aqueduct's head to create a reservoir fountain. A major flood in early 1841 destroyed the original dam, filling Croton Bay with earth and gravel. The dam was rebuilt at greater altitude, creating a lake nearly six miles long holding approximately 500,000,000 gallons.

The reservoir sat 166 feet above mean tide-water at New York and supplied 40,000,000 to 50,000,000 gallons daily through the aqueduct. The aqueduct ran parallel to the Hudson, approximately half a mile away throughout its length. White stone ventilator towers, about fifteen feet tall, marked its course at mile intervals.

Some ventilators featured ornamental designs (like the one at Sing Sing), while others were simple round towers. Every third tower had a square base with a door permitting entry into the aqueduct. Iron screens topped each tower to prevent debris from entering.

The completed aqueduct cost approximately $12,000,000 and opened to New York City residents in autumn 1842. Van Cortlandt Manor: Colonel Pierre Van Cortlandt invited Lossing to lodge at the manor house.