Ocoee Dam No. 3 is a
hydroelectric dam
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...
on the
Ocoee River
The Toccoa River and Ocoee River are the names in use for a single river that flows northwestward through the southern Appalachian Mountains of the southeastern United States. It is a tributary of the Hiwassee River, which it joins in Polk Coun ...
in
Polk County Polk County is the name of twelve counties in the United States, all except two named after president of the United States James Knox Polk:
* Polk County, Arkansas
* Polk County, Florida
* Polk County, Georgia
* Polk County, Iowa
* Polk Count ...
, in the U.S. state of
Tennessee
Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
. It is one of four dams on the Toccoa/Ocoee River owned and operated by the
Tennessee Valley Authority
The Tennessee Valley Authority (TVA) is a federally owned electric utility corporation in the United States. TVA's service area covers all of Tennessee, portions of Alabama, Mississippi, and Kentucky, and small areas of Georgia, North Carolin ...
, which built the dam in the early 1940s to meet emergency demands for electricity during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
. The dam impounds the Ocoee No. 3 Reservoir, which stretches upriver to the Tennessee-
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
state line.
[Tennessee Valley Authority]
Ocoee Reservoir No. 3
Retrieved: 23 January 2009. Ocoee No. 3's powerhouse is actually located several miles downstream from the dam, and is fed by a conduit that carries water to it from the reservoir.
[Tennessee Valley Authority, ''The Hiwassee Valley Projects Volume 2: The Apalachia, Ocoee No. 3, Nottely, and Chatuge Projects'', Technical Report No. 5 (Washington, D.C.: U.S. Government Printing Office, 1948), pp. 1-13, 40, 47, 63, 295, 494.]
Location
Ocoee Dam No. 3 is located above the mouth of the Ocoee River, where the river slices a deep gap between Little Frog Mountain to the north and
Big Frog Mountain to the south. Both of these mountains are protected by federal wilderness areas which are adjacent to TVA's Ocoee No. 3 reservation boundary.
Ocoee Dam No. 2 is just downstream, and
Blue Ridge Dam
Blue Ridge Dam is a hydroelectric dam on the Toccoa River in Fannin County, in the U.S. state of Georgia. It is the uppermost of four dams on the Toccoa/Ocoee River owned and operated by the Tennessee Valley Authority. The dam impounds the Bl ...
is upstream. The Toccoa River, which flows down from its source in the
Blue Ridge Mountains
The Blue Ridge Mountains are a Physiographic regions of the world, physiographic province of the larger Appalachian Mountains range. The mountain range is located in the Eastern United States, and extends 550 miles southwest from southern Pennsy ...
of northern Georgia, enters Tennessee (where it becomes the Ocoee River) approximately upstream from Ocoee Dam No. 3, near the
Copperhill area. The
Ocoee Scenic Byway
The Ocoee Scenic Byway is a National Forest Scenic Byway and Tennessee Scenic Byway that traverses through the Cherokee National Forest, in East Tennessee. It is part of both U.S. Route 64 and U.S. Route 74, and features the Ocoee Whitewater C ...
— which is part of
U.S. Route 64
U.S. Route 64 (US 64) is an east–west United States highway that runs for 2,326 miles (3,743 km) from Nags Head in eastern North Carolina to just southwest of the Four Corners in northeast Arizona. The western terminus is at U.S. Route 1 ...
— passes just north of the dam.
Capacity
Ocoee Dam No. 3 is a concrete gravity diversion-type dam high and long, and has a generating capacity of 28,800 kilowatts. The dam's concrete overfall spillway has a discharge capacity of , of which is via the dam's two by sluice gates located near the bottom of the dam. Ocoee Reservoir No. 3 has of water surface and of shoreline.
Major recreational releases are typically scheduled for weekends during the summer months.
[Tennessee Valley Authority]
Ocoee No. 3 Recreational Release Schedule
Retrieved: 23 January 2009.
The powerhouse of Ocoee No. 3 was built downstream from the dam in order to obtain maximum utilization of the elevation loss along this stretch of the river. A high pressure conduit— most of which flows through a by tunnel carved into the mountainside— carries the water from the reservoir at a relatively steady elevation. The water emerges from the tunnel at a point from the reservoir intake and drops through a steel
penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is inherited from the earlier technology of mill ponds and watermills.
H ...
to the powerhouse's lone turbine.
Background and construction
The rapid-flowing Ocoee River's hydroelectric potential has been exploited by private interests, namely the Eastern Tennessee Power Company and its successor, the Tennessee Electric Power Company (TEPCO), since the completion of
Ocoee Dam No. 1 in late 1911. While only a stretch of river remained between Ocoee Dam No. 2 (completed in 1913) and Blue Ridge Dam (completed in 1931), this stretch's average elevation loss of per mile made a third dam possible. The
U.S. Army Corps of Engineers
, colors =
, anniversaries = 16 June (Organization Day)
, battles =
, battles_label = Wars
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had surveyed the Ocoee No. 3 dam site in the late 1920s, and TEPCO had already purchased the necessary land and water rights for the dam by the 1930s.
![Ocoee-dam-3-tva1](https://upload.wikimedia.org/wikipedia/commons/8/84/Ocoee-dam-3-tva1.jpg)
The TVA Act of 1933 created the Tennessee Valley Authority and gave the Authority oversight of the entire
Tennessee River
The Tennessee River is the largest tributary of the Ohio River. It is approximately long and is located in the southeastern United States in the Tennessee Valley. The river was once popularly known as the Cherokee River, among other name ...
watershed, which includes the Ocoee. In 1939, a
U.S. Supreme Court
The Supreme Court of the United States (SCOTUS) is the highest court in the federal judiciary of the United States. It has ultimate appellate jurisdiction over all U.S. federal court cases, and over state court cases that involve a point o ...
ruling forced TEPCO to sell TVA its assets, which included the tract for Ocoee No. 3. While TVA identified the Ocoee No. 3 site as part of its Hiwassee Valley surveys in 1934, the idea for the dam received little attention until the outbreak of World War II in Europe sparked a need for increased
aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...
production at the
ALCOA plant in
Alcoa, Tennessee
Alcoa is a city in Blount County, Tennessee, United States, south of Knoxville. Its population was 10,978 at the 2020 census. It is part of the Knoxville, Tennessee Metropolitan Statistical Area.
As its name suggests, Alcoa was the site of a lar ...
, which required large amounts of electricity. The Ocoee No. 3 project, along with several other dam projects in the Hiwassee watershed, was authorized on July 16, 1941. Construction began the following day.
Most of the land necessary for the construction of Ocoee Dam No. 3 and its reservoir had been obtained from TEPCO, and thus no residential or cemetery relocations were necessary. Work progressed at a steady pace, and the dam was completed on August 15, 1942. The diversion tunnel was completed in November of the same year, but budget delays prevented the dam's generator from becoming operational until April 30, 1943.
January 2009 sludge release
On January 4, 2009, TVA released a substantial amount of contaminated sludge-like material from the Ocoee No. 3 Reservoir into the Upper Ocoee immediately downstream, killing an undetermined number of fish and covering the river with a layer of "foul-smelling" sludge as far downstream as the Ocoee No. 2 Reservoir. The sludge was filled with contaminants— including copper, iron, and zinc— left over from the
mining operations that once denuded the Ducktown Basin, which is adjacent to the Ocoee No. 3 reservoir. The release polluted the
Ocoee Whitewater Center
The Ocoee Whitewater Center, near Ducktown, Tennessee, United States, was the canoe slalom venue for the 1996 Summer Olympics in Atlanta, and is the only in-river course to be used for Olympic slalom competition. A 1,640 foot (500 m) stretch of t ...
, which is two miles (3 km) downstream from Ocoee Dam No. 3.
[Scott Barker,]
TVA Probed in Ocoee Release
." ''Knoxnews.com'', 14 January 2009. Retrieved: 28 January 2009.
TVA stated that the release was part of routine maintenance in anticipation of rain showers. The material was released via the dam's sluice gates, which are located at the bottom of the dam and are typically used for low-level and recreational releases. On January 12, 2009, in response to the incident, the
Tennessee Department of Environment and Conservation
The Tennessee Department of Environment and Conservation (TDEC) is a Cabinet-level agency within the government of the U.S. state of Tennessee, headed by the Tennessee Commissioner of Environment and Conservation.
The Department of Conservation ...
issued a notice of violation that ordered TVA to get state approval before using the dam's sluice gates, restore the affected areas, and submit a management plan for sluicing operations at the dam.
References
External links
Ocoee Reservoir No. 3— official TVA site
{{Tennessee Valley Authority Facilities
Dams on the Hiwassee River
Tennessee Valley Authority dams
Buildings and structures in Polk County, Tennessee
Dams in Tennessee
Hydroelectric power plants in Tennessee
Dams completed in 1943
Energy infrastructure completed in 1943
1943 establishments in Tennessee