Lock and Dam No. 7 is 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 whose water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the...
and
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...
located near
Onalaska, WisconsinOnalaska is a city in La Crosse County, Wisconsin, and the largest suburb of the city of La Crosse. The population was 14,839 at the 2000 census. Its estimated 2008 population was 16,778. The city borders La Crosse directly to the north and three unincorporated rural towns: Onalaska, Medary, and...
on the
UpperThe 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 RiverThe Mississippi River is the second longest river in the United States, with a length of from its source in Lake Itasca in Minnesota to its mouth in the Gulf of Mexico....
. It forms pool 7 and
Lake OnalaskaLake Onalaska is a reservoir located on the Mississippi River between Wisconsin, and Minnesota. It is approximately 4 miles across, and is the widest point on the Mississippi River. Located in La Crosse County in the state of Wisconsin, its latitude and longitude are . The lake is 7,688 acres and...
.
The facility is located on Mississippi
River mileA 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...
702.5 near
La Crescent, MinnesotaLa Crescent is a city in Houston and Winona counties in the U.S. state of Minnesota. It is located in the La Crosse Metropolitan Area, located directly across the Mississippi River...
. It was constructed and placed in operation in April, 1937 and underwent major rehabilitation from 1989 through 2002.
The dam consists of concrete structure long, five
roller gatesA Roller dam is a type of hydro control device which is specially designed to mitigate erosion. They are most often used to divert water for irrigation but the largest and most outstanding examples are employed to ease river navigation.- Use :...
and 11
tainter gateThe 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. Two segments of earth embankment long from dam to French Island.
Lock and Dam No. 7 is 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 whose water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the...
and
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...
located near
Onalaska, WisconsinOnalaska is a city in La Crosse County, Wisconsin, and the largest suburb of the city of La Crosse. The population was 14,839 at the 2000 census. Its estimated 2008 population was 16,778. The city borders La Crosse directly to the north and three unincorporated rural towns: Onalaska, Medary, and...
on the
UpperThe 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 RiverThe Mississippi River is the second longest river in the United States, with a length of from its source in Lake Itasca in Minnesota to its mouth in the Gulf of Mexico....
. It forms pool 7 and
Lake OnalaskaLake Onalaska is a reservoir located on the Mississippi River between Wisconsin, and Minnesota. It is approximately 4 miles across, and is the widest point on the Mississippi River. Located in La Crosse County in the state of Wisconsin, its latitude and longitude are . The lake is 7,688 acres and...
.
The facility is located on Mississippi
River mileA 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...
702.5 near
La Crescent, MinnesotaLa Crescent is a city in Houston and Winona counties in the U.S. state of Minnesota. It is located in the La Crosse Metropolitan Area, located directly across the Mississippi River...
. It was constructed and placed in operation in April, 1937 and underwent major rehabilitation from 1989 through 2002.
The dam consists of concrete structure long, five
roller gatesA Roller dam is a type of hydro control device which is specially designed to mitigate erosion. They are most often used to divert water for irrigation but the largest and most outstanding examples are employed to ease river navigation.- Use :...
and 11
tainter gateThe 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. Two segments of earth embankment long from dam to French Island. One concrete
spillwayA spillway is a structure used to provide for the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. Spillways release floods so that the water does not overtop and damage or even destroy the dam. Except during flood periods, water...
long. And long from
French Island, WisconsinFrench Island is a census-designated place in La Crosse County, Wisconsin, United States. The population was 4,410 at the 2000 census. It lies on an island of a similar name, with which it is not coextensive; most of the island is part of the city of La Crosse, but all are part of the La Crosse...
to
Onalaska, WisconsinOnalaska is a city in La Crosse County, Wisconsin, and the largest suburb of the city of La Crosse. The population was 14,839 at the 2000 census. Its estimated 2008 population was 16,778. The city borders La Crosse directly to the north and three unincorporated rural towns: Onalaska, Medary, and...
. The concrete spillway is long and the lock is wide by long.
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