Lock and Dam No. 8
Encyclopedia
Lock (water transport)
A 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...
and dam
Dam
A 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...
located near Genoa, Wisconsin
Genoa, Wisconsin
Genoa is a village in Vernon County, Wisconsin, United States. The population was 263 at the 2000 census. The village is within the Town of Genoa. There is also a village named Genoa City, Wisconsin.-Economy:...
on the Upper
Upper Mississippi River
The Upper Mississippi River is the portion of the Mississippi River upstream of Cairo, Illinois, United States. From the headwaters at Lake Itasca, Minnesota, the river flows approximately 2000 kilometers to Cairo, where it is joined by the Ohio River to form the Lower Mississippi...
Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
River near river mile
River mile
In the United States, a River mile is a measure of distance in miles along a river from its mouth. River mile numbers begin at zero and increase further upstream. The corresponding metric unit using kilometers is the River kilometer...
679.2. It was constructed and put into operation by April 1937. The site underwent major rehabilitation from 1989 through 2003.
The dam consists of a concrete structure 934 feet (284.7 m) long with five roller gates
Roller dam
A Roller dam is a type of hydro-control device specially designed to mitigate erosion. They are most often used to divert water for irrigation but the largest and most notable examples are used to ease river navigation.- Use :...
and 10 tainter gate
Tainter gate
The Tainter gate is a type of radial arm floodgate used in dams and canal locks to control water flow. It is named for Wisconsin structural engineer Jeremiah Burnham Tainter....
s. The earth embankment is 17500 feet (5,334 m) long with two submersible spillway
Spillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
s, 938 feet (285.9 m) long and 1338 feet (407.8 m) long. The lock is 110 feet (33.5 m) wide by 600 feet (182.9 m) long.