The
Federal Dam is a manmade
damA dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
built across the
Hudson RiverThe Hudson is a river that flows from north to south through eastern New York. The highest official source is at Lake Tear of the Clouds, on the slopes of Mount Marcy in the Adirondack Mountains. The river itself officially begins in Henderson Lake in Newcomb, New York...
in the US state of
New YorkNew York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
from
TroyTroy is a city in the US State of New York and the seat of Rensselaer County. Troy is located on the western edge of Rensselaer County and on the eastern bank of the Hudson River. Troy has close ties to the nearby cities of Albany and Schenectady, forming a region popularly called the Capital...
on the east bank to
Green IslandGreen Island is a coterminous town and village in Albany County, New York, USA some 8 miles north of Albany, New York. Green Island is one of only five such town-village amalgams in New York. The population was 2,620 at the 2010 census...
on the west bank. The major function of the dam is to improve navigability. It is located at mile 153 of the Hudson River, measuring from the beginning of the Hudson as a Federally Navigable Waterway near the Battery in
ManhattanManhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...
. The location of the dam marks the northern end of the Hudson River
estuaryAn estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
.
The Federal Lock
In order to allow ships to move freely, the eastern end of the dam contains a
lockA lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...
, commonly called the
Federal Lock or (on some charts and publications) the "
Troy-US Lock." The lock, which was opened in 1916, has a single chamber and is 520 feet (158.5 m) long, 45 feet (13.7 m) wide, 17 feet (5.2 m) deep, and has a lift of approximately 14 feet (4.3 m). Although it is the first lock encountered by vessels passing from the Hudson River into the
Great LakesThe Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
by way of the
New York State Canal SystemThe New York State Canal System is a successor to the Erie Canal and other canals within New York...
, and it is sometimes referred to as lock "E-1," it is not part of the
Erie CanalThe Erie Canal is a waterway in New York that runs about from Albany, New York, on the Hudson River to Buffalo, New York, at Lake Erie, completing a navigable water route from the Atlantic Ocean to the Great Lakes. The canal contains 36 locks and encompasses a total elevation differential of...
(which officially has no "Lock 1"), nor maintained by the
New York State Canal CorporationThe New York State Canal Corporation is a subsidiary of the New York State Thruway Authority. It is responsible for the oversight, administration and maintenance of the New York State Canal System, which consists of the Erie Canal, Cayuga–Seneca Canal, Oswego Canal and Champlain Canal...
. Both the lock and the dam were built and are currently operated by the
U.S. Army Corps of EngineersThe United States Army Corps of Engineers is a federal agency and a major Army command made up of some 38,000 civilian and military personnel, making it the world's largest public engineering, design and construction management agency...
; as of September 2006, it was listed as being in "Operational" condition.