Douglas Dam
Encyclopedia
Douglas Dam is a hydroelectric dam on the French Broad River
French Broad River
The French Broad River flows from near the village of Rosman in Transylvania County, North Carolina, into the state of Tennessee. Its confluence with the Holston River at Knoxville is the beginning of the Tennessee River....

 in Sevier County, Tennessee
Sevier County, Tennessee
Sevier County is a county of the state of Tennessee, United States. Its population was 71,170 at the 2000 United States Census. It is included in the Sevierville, Tennessee, Micropolitan Statistical Area, which is included in the Knoxville-Sevierville-La Follette, TN Combined Statistical Area. The...

, in the southeastern United States. The dam is operated by the Tennessee Valley Authority (TVA)
Tennessee Valley Authority
The Tennessee Valley Authority is a federally owned corporation in the United States created by congressional charter in May 1933 to provide navigation, flood control, electricity generation, fertilizer manufacturing, and economic development in the Tennessee Valley, a region particularly affected...

, which built the dam in record time in the early 1940s to meet emergency energy demands at the height of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Douglas Dam is a straight reinforced concrete
Reinforced concrete
Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...

 gravity-type dam 1705 feet (520 m) long and 202 feet (62 m) high, impounding the 28420 acres (11,501.2 ha) Douglas Lake
Douglas Lake
Douglas Lake, also called Douglas Reservoir, is a reservoir created by an impoundment of the French Broad River in Eastern Tennessee. This lake is located only a few miles from the Pigeon Forge/Gatlinburg area, and also the Great Smoky Mountains National Park...

. The dam was named for Douglas Bluff, a cliff overlooking the dam site prior to construction.

Location and access

The French Broad River winds its way westward from the Appalachian Mountains
Appalachian Mountains
The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...

, gaining considerable strength after absorbing the Pigeon River
Pigeon River (Tennessee - North Carolina)
The Pigeon River of western North Carolina and east Tennessee rises above Canton, North Carolina. Below this, it flows roughly parallel to Interstate 40 for many miles and is impounded by a dam -- Walters Dam -- belonging to Progress Energy before entering Tennessee, where it flows into the French...

 and Nolichucky River
Nolichucky River
The Nolichucky River is a major stream draining the Blue Ridge Mountains of western North Carolina and east Tennessee. The river is long.-Hydrography:...

 near Newport
Newport, Tennessee
Newport is a city in Cocke County, Tennessee, United States. The population was 7,242 at the 2000 census. It is the county seat of Cocke County.-Geography:...

 before eventually joining with the Holston River
Holston River
The Holston River is a major river system of southwestern Virginia and east Tennessee. The three major forks of the Holston rise in southwestern Virginia and have their confluence near Kingsport, Tennessee. The North Fork flows southwest from Sharon Springs in Bland County, Virginia...

 at Knoxville
Knoxville, Tennessee
Founded in 1786, Knoxville is the third-largest city in the U.S. state of Tennessee, U.S.A., behind Memphis and Nashville, and is the county seat of Knox County. It is the largest city in East Tennessee, and the second-largest city in the Appalachia region...

 to form the Tennessee River
Tennessee River
The Tennessee River is the largest tributary of the Ohio River. It is approximately 652 miles 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 names...

. Douglas Dam is located 32 miles (51.5 km) above the mouth of the French Broad. The area is a geological border between the Foothills of the Great Smoky Mountains
Great Smoky Mountains
The Great Smoky Mountains are a mountain range rising along the Tennessee–North Carolina border in the southeastern United States. They are a subrange of the Appalachian Mountains, and form part of the Blue Ridge Physiographic Province. The range is sometimes called the Smoky Mountains or the...

 (which rise to the south) and the Appalachian Ridge-and-Valley range
Ridge-and-valley Appalachians
The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are also a belt within the Appalachian Mountains extending from southeastern New York through northwestern New...

. The reservoir includes parts of Sevier, Jefferson
Jefferson County, Tennessee
*...

, Hamblen, and Cocke counties.

Road access is available by Tennessee State Hwy 338 which crosses just downstream of the dam. Interstate 40
Interstate 40
Interstate 40 is the third-longest major east–west Interstate Highway in the United States, after I-90 and I-80. Its western end is at Interstate 15 in Barstow, California; its eastern end is at a concurrency of U.S. Route 117 and North Carolina Highway 132 in Wilmington, North Carolina...

 (Exit 407) passes a few miles to the north.

The dam does not have any navigational locks
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...

.

Background and construction

During 1941, President Franklin D. Roosevelt
Franklin D. Roosevelt
Franklin Delano Roosevelt , also known by his initials, FDR, was the 32nd President of the United States and a central figure in world events during the mid-20th century, leading the United States during a time of worldwide economic crisis and world war...

 requested Congress to allocate funding for a dam on the French Broad River in East Tennessee
East Tennessee
East Tennessee is a name given to approximately the eastern third of the U.S. state of Tennessee, one of the three Grand Divisions of Tennessee defined in state law. East Tennessee consists of 33 counties, 30 located within the Eastern Time Zone and three counties in the Central Time Zone, namely...

. After the Attack on Pearl Harbor
Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...

 brought the United States into World War II, construction of this dam became a high priority in order to generate hydroelectric power for national defense purposes, particularly in the production of aluminum and magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

 - vital metals for wartime warplane-manufacturing. When TVA first asked Congress for the funds to construct Douglas Dam in late 1941, U.S. Senator Kenneth McKellar
Kenneth McKellar
Kenneth Douglas McKellar was an American politician from Tennessee who served as a United States Representative from 1911 until 1917 and as a United States Senator from 1917 until 1953...

 of Tennessee opposed the project because it would flood some 40 square miles (103.6 km²) of fertile farmland important to the local food canning
Canning
Canning is a method of preserving food in which the food contents are processed and sealed in an airtight container. Canning provides a typical shelf life ranging from one to five years, although under specific circumstances a freeze-dried canned product, such as canned, dried lentils, can last as...

 industry. McKellar succeeded in blocking this project for two months, but then his opposition to it was overridden due to needs of national defense. The Office of Production Management
War Production Board
The War Production Board was established as a government agency on January 16, 1942 by executive order of Franklin D. Roosevelt.The purpose of the board was to regulate the production and allocation of materials and fuel during World War II in the United States...

 predicted that wartime industrial production
Industry
Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...

 would peak in 1943, and that the generating capacity of existing and planned TVA projects would be short by 230,000 kilowatts of electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

. Congress approved the project in January 1942 and President Roosevelt signed the bill into law on January 30, 1942. Construction began immediately on February 2 as a rush project, and it utilized blueprint
Blueprint
A blueprint is a type of paper-based reproduction usually of a technical drawing, documenting an architecture or an engineering design. More generally, the term "blueprint" has come to be used to refer to any detailed plan....

s, civil engineer
Civil engineer
A civil engineer is a person who practices civil engineering; the application of planning, designing, constructing, maintaining, and operating infrastructures while protecting the public and environmental health, as well as improving existing infrastructures that have been neglected.Originally, a...

s, construction worker
Construction worker
A construction worker or builder is a professional, tradesman, or labourer who directly participates in the physical construction of infrastructure.-Construction trades:...

s, and construction machinery from the nearby Cherokee Dam
Cherokee Dam
Cherokee Dam is a hydroelectric dam located on the Holston River in Grainger County and Jefferson County, Tennessee, in the southeastern United States. The dam is operated and maintained by the Tennessee Valley Authority, which built the dam in the early 1940s to help meet urgent demands for...

, which had just been completed a few weeks earlier in late 1941.

The construction of the Douglas Dam and its accompanying reservoir required the purchase of 33160 acres (13,419.4 ha) of land, 5182 acres (2,097.1 ha) of which were forested and had to be cleared. This project also required the relocation of 525 families and 32 cemeteries, and the rerouting of several miles of roads. Supplies for the construction of the dam were hauled to the site by the Smoky Mountain Railroad
Smoky Mountain Railroad
The Smoky Mountain Railroad was a short standard gauge rail line that ran from Knoxville, Tennessee to Sevierville, Tennessee from 1910 until 1962....

, which had constructed a spur line to the site from nearby Sevierville. Profits from supporting the dam construction saved this railroad from bankruptcy.

The Douglas Project required the construction of ten smaller earthen saddle dams to fill in gaps along the adjacent ridgeline and permit a higher water elevation than would otherwise be possible. Most of these saddle dams are located in the hills southeast of the main dam, although one protects downtown Dandridge, which along with the communities of Shady Grove, Oak Grove, and Rankin, was scheduled to be flooded. However, the citizens of Dandridge appealed to the First Lady
First Lady of the United States
First Lady of the United States is the title of the hostess of the White House. Because this position is traditionally filled by the wife of the president of the United States, the title is most often applied to the wife of a sitting president. The current first lady is Michelle Obama.-Current:The...

, Eleanor Roosevelt
Eleanor Roosevelt
Anna Eleanor Roosevelt was the First Lady of the United States from 1933 to 1945. She supported the New Deal policies of her husband, distant cousin Franklin Delano Roosevelt, and became an advocate for civil rights. After her husband's death in 1945, Roosevelt continued to be an international...

, pointing out that this town was the only place in the United States named for Martha Washington
Martha Washington
Martha Dandridge Custis Washington was the wife of George Washington, the first president of the United States. Although the title was not coined until after her death, Martha Washington is considered to be the first First Lady of the United States...

, the wife of the first president George Washington
George Washington
George Washington was the dominant military and political leader of the new United States of America from 1775 to 1799. He led the American victory over Great Britain in the American Revolutionary War as commander-in-chief of the Continental Army from 1775 to 1783, and presided over the writing of...

. Mrs. Roosevelt made certain that a saddle dam was built to protect the town of Dandridge from flooding. The saddle dam was built of earthen fill, and reinforced on its lakeside by gravel and riprap
Riprap
Riprap — also known as rip rap, rubble, shot rock or rock armour or "Rip-rap" — is rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour, water or ice erosion.It is made from a variety of rock types, commonly granite or...

.

In spite of a four-week work delay caused by flooding, the Douglas Dam was completed and its floodgates were closed on February 19, 1943, just 382 days after the construction began, setting a world record
World record
A world record is usually the best global performance ever recorded and verified in a specific skill or sport. The book Guinness World Records collates and publishes notable records of all types, from first and best to worst human achievements, to extremes in the natural world and beyond...

 for a project of its size. Its first electric generator went on-line on March 21, 1943, and its second one went on-line on January 1, 1944. Its powerhouse operated at maximum capacity for most of its first year of operation. After its completion, the Douglas Dam powerhouse furnished electric power for two critical war industries, aluminum production and the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...

's uranium enrichment operations at nearby Oak Ridge.

Power generation, flood control, and other purposes

The Douglas Dam powerhouse is a hydroelectric power producer with four large water turbine
Water turbine
A water turbine is a rotary engine that takes energy from moving water.Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy...

s that drive four large electric generators. Their combined peak electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

-production capacity is 165,600 kilowatts.

In addition to hydroelectric generation, there are several secondary purposes of the Douglas dam and reservoir. One of these is flood control
Flood control
In communications, flood control is a feature of many communication protocols designed to prevent overwhelming of a destination receiver. Such controls can be implemented either in software or in hardware, and will often request that the message be resent after the receiver has finished...

 for the French Broad River and also for the Tennessee River downstream. Douglas Lake's flood-storage capacity is about 1081880 acre.ft of water.

In addition to flood-control purposes, the water stored in Douglas Lake
Douglas Lake
Douglas Lake, also called Douglas Reservoir, is a reservoir created by an impoundment of the French Broad River in Eastern Tennessee. This lake is located only a few miles from the Pigeon Forge/Gatlinburg area, and also the Great Smoky Mountains National Park...

 serves an important purpose during extended dry periods and drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...

s in East Tennessee
East Tennessee
East Tennessee is a name given to approximately the eastern third of the U.S. state of Tennessee, one of the three Grand Divisions of Tennessee defined in state law. East Tennessee consists of 33 counties, 30 located within the Eastern Time Zone and three counties in the Central Time Zone, namely...

 and western North Carolina. Then, water is released from this and other dams on the upper tributaries of the Tennessee River in order to maintain an eight-foot-deep navigation channel for barges on the inland waterway of the river from Knoxville down to its mouth at the Ohio River
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...

. If it were not for these releases of water, parts of the Tennessee River would become unnavigable. Furthermore, the water that is released is then available for all the drinking-water supplies of cities and towns downstream, and in addition, it is available for watering farms during the droughts.

Another secondary purpose of the Douglas Dam and Douglas Lake is for recreational boating
Boating
Boating is the leisurely activity of travelling by boat, or the recreational use of a boat whether powerboats, sailboats, or man-powered vessels , focused on the travel itself, as well as sports activities, such as fishing or water skiing...

, swimming, and fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....

. Significant amounts of freshwater fish
Freshwater fish
Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity...

 are caught in Douglas Lake as part of the food supply for human beings. Douglas Lake has an average of 500 miles (800 km) of shoreline, and it has an average surface area of nearly 30,000 acre
Acre
The acre is a unit of area in a number of different systems, including the imperial and U.S. customary systems. The most commonly used acres today are the international acre and, in the United States, the survey acre. The most common use of the acre is to measure tracts of land.The acre is related...

s (120 square kilometers), with both measurements varying according to the seasonally-changing water level of Douglas Lake.

Douglas Lake is the recreational destination for up to two million visitors per year. Primary uses of the lake and its shores are fishing, boating, water skiing, swimming, camping, hiking, and wildlife observing. In addition to a number of private campgrounds in this area, TVA provides the Douglas Dam Headwater Campground and the Douglas Dam Tailwater Campground for public use. The Tennessee Wildlife Resources Agency
Tennessee Wildlife Resources Agency
The Tennessee Wildlife Resources Agency is an independent state agency of the state of Tennessee with the mission of managing the state's fish and wildlife and their habitats, as well as responsibility for all wildlife-related law enforcement activities...

 stocks Douglas Lake tens of thousands of sauger
Sauger
The sauger is a freshwater perciform fish of the family Percidae which resembles its close relative the walleye. They are members of the largest vertebrate order, Perciforms. They are the most migratory percid species in North America. Saugers obtain two dorsal fins, the first is spiny and the...

 and crappie
Crappie
Crappie is a genus of freshwater fish in the sunfish family of order Perciformes. The type species is P. annularis, the white crappie...

 fish each year to thrive and then provide recreational and food fishing.

Ecological effects

One of the problems of hydroelectric dams is the periodic reduction of dissolved oxygen in the tailwaters downstream of the dam. Three systems are used at Douglas Dam to improve oxygenation.
  • 1. Turbine venting - injection of oxygen at the water turbine
    Water turbine
    A water turbine is a rotary engine that takes energy from moving water.Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy...

    s.
  • 2. Surface water pumps - pumps that push surface water downward to the turbines.
  • 3. Water pulsing - periodic release of water through the power turbines to maintain some water flow downstream at all times.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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