Originally, the Bronx Kill was a sizeable waterway, approximately 600 feet (180 m) in width. There were also plans[when?] by the War Department to dredge a 24-foot (7.3 m) deep channel, 480 feet (150 m) in width, to improve navigation and reduce tidal currents. For this reason, in the early 20th century the New York Connecting Railroad built a movable bridge across the Bronx Kill on the approach to the Hell Gate Bridge. Similarly, the truss bridge of the Triborough Bridge across the Bronx Kill was designed to be convertible to a lift bridge. However, much of the Bronx Kill was later filled in to expand the parkland on Randalls Island.
The Bronx Kill offers a venue for kayakers and other human-powered boaters without the worry of larger vessel traffic. Canoe and kayak expeditions through the waterway begin on the Harlem River, near the Third Avenue Bridge. Crossings must be well timed for the tides, to ensure both the correct current direction and sufficient water height: at low water, parts of the Bronx Kill entirely bottom out, revealing muddy stretches, abandoned cars and other assorted junk. There is also low clearance above the electrical conduits that supply power to Randalls Island. Consequently, no commercial vessels navigate the kill, with local businesses mostly opting instead for road and rail transport, including the Oak Point Link along its north bank.
In 2001, the New York Power Authority offered to construct a pedestrian bridge linking the Bronx with Randalls Island—part of the agency's remuneration to the community for building two new power plants in the South Bronx. That plan, however, fell by the wayside when local officials argued that an improved Triborough Bridge path would be sufficient. The state authority instead committed millions of dollars to energy efficiency measures in the borough as a whole, including a recently unveiled green roof on the Bronx County Courthouse. A Randalls Island Connector is planned to cross the Kill to connect the island to the South Bronx Greenway.
A 2006 plan for a water park—the first in the nation for a large city—on the northwest corner of Randalls Island was controversial. Announced by the Giuliani administration as a $48 million, 15-acre (61,000 m2) project, the proposal expanded to encompass 26 acres (110,000 m2) at a projected cost of $168 million before being cancelled in 2007.
- Ammann, O.H. (August 1917). "The Hell Gate Arch Bridge and Approaches of the New York Connecting Railroad over the East River in New York City". Proceedings of the American Society of Civil Engineers 43: 1763–1767.
- Harlem, NY-NJ Quadrangle (Map). 1:62,500. 15 Minute Series (Topographic). United States Geological Survey. 1900. § SW. Retrieved 2010-02-21.
- Rastorfer, Darl (2000). Six Bridges: The Legacy of Othmar H. Ammann. New Haven: Yale University Press. p. 166. ISBN 0-300-08047-6.
- Bindley, Katherine (September 6, 2008). "On the Water, a Tight Fit and Nervous Boaters". The New York Times. Retrieved 2009-09-18.
- Koh, Eun Lee (March 4, 2001). "Not Merely a Footbridge, but a Path to a Rare Oasis". The New York Times. Retrieved 2010-02-21.
- "South Bronx Greenway". New York City Economic Development Corporation. Retrieved 2010-10-14.
- Danis, Kirsten (September 22, 2007). "City Cancels Plans for Randalls Island Water Park". Daily News (New York). Retrieved 2011-02-24.