Calderwood Dam | |
Location | Blount / Monroe counties, Tennessee |
---|---|
Nearest city | Maryville, Tennessee |
Area | 30 acres (12 ha) |
Built | 1930 |
Architect | I.V. Karpov |
MPS | Blount County MPS; Pre-TVA Hydroelectric Power Development in Tennessee MPS |
NRHP reference No. | 89001069 (original) 90001016 (increase) |
Significant dates | |
Added to NRHP | August 21, 1989 |
Boundary increase | July 3, 1990 |
Calderwood Dam is a hydroelectric dam located along the Little Tennessee River in Blount and Monroe counties, in the U. S. state of Tennessee. Completed in 1930, the dam is owned and maintained by Tapoco, a subsidiary of the Aluminum Company of America (Alcoa), although the Tennessee Valley Authority (TVA) controls the dam's reservoir levels from Fontana Dam further upstream. [1] Calderwood Dam is named for Alcoa engineer Isaac Glidden Calderwood (1871–1941), who supervised much of the company's early Little Tennessee River operations. [2]
Calderwood Dam was one of four dams—along with Cheoah, Santeetlah, and Chilhowee —built in the Little Tennessee Valley by Alcoa in the 20th century to provide electricity to its aluminum smelting operations in Blount County. The dam was one of the last to be completed in the Tennessee River watershed before TVA took control of the watershed in 1933. Alcoa developed the community of Calderwood, Tennessee, just downstream from the dam to house construction and maintenance crews for its Little Tennessee Valley operations. In 1989, Calderwood Dam was placed on the National Register of Historic Places. The listing was expanded in 1990 and again in 2004 to include most of the dam's substructures. [3]
Calderwood Dam is located approximately 44 miles (71 km) upstream from the mouth of the Little Tennessee River, which flows westward from North Carolina and empties into the Tennessee River. The area is surrounded by mountains on all sides, with the Great Smoky Mountains rising to the north and the Unicoi Mountains rising to the south. U.S. Route 129 runs roughly parallel to the Blount County side of the river, providing the only major road access to the Calderwood area.
The Calderwood complex graces a horseshoe bend in the river known as "The Narrows." The dam is located along the upstream end of this bend, and the powerhouse, service building, and old Calderwood community (now a recreation area) are located along the downstream end of this bend. The service building, recreation area, and historical community structures are accessible via Housley Road (gated at night), which connects US-129 to Growdon Road at the service building. Growdon Road continues past the service building to the powerhouse, although this section of the road is only publicly open to foot traffic. The Calderwood Overlook, located along US-129 just south of the road's intersection with Housley Road, provides a sweeping view of the Calderwood Reservoir. A gravel road, also open only to public foot traffic, connects the overlook to Calderwood Dam.
Calderwood Dam is a thin-section concrete structure 232 feet (71 m) high and 916 feet (279 m) wide, [4] and has a 24-gate arched-crest spillway. A 40-foot (12 m) lower-gravity "cushion" dam is located 370 feet (110 m) downstream from the main dam, creating a pool of water that protects the riverbed. The pool's effectiveness is enhanced by a deflection unit at the base of the main dam. [5]
Calderwood's powerhouse is located 1.2 miles (1.9 km) downstream from the dam, on the opposite side of the horseshoe bend in the river. A submerged intake just upstream from the dam diverts water into a 2,150-foot (660 m) concrete tunnel, which carries the water to the other side of the peninsula where it spills down three penstocks to a valve house. The penstocks measure approximately 18 feet (5.5 m) in diameter, and range in length from 330 feet (100 m) to 388 feet (118 m). The valve house is built of steel-reinforced concrete and is equipped with three Francis turbines. [5] The powerhouse, a larger brick structure adjacent to the valve house, is equipped with three Westinghouse generators with a combined capacity of 140.4 megawatts. [1] The powerhouse complex, located adjacent to a rockslide-prone slope, is protected by a V-shaped reinforced concrete wall. [5]
Calderwood's reservoir covers approximately 570 acres (230 ha) with a drainage area of 1,856 square miles (4,810 km2). The elevation of Calderwood Reservoir is 1087.8 feet (USGS), and the reservoir covers an 8-mile (13 km) stretch of the river. About half of Calderwood Reservoir lies in Tennessee, with the remainder extending into North Carolina. [1]
Alcoa began developing the Little Tennessee Valley in 1909 to provide the enormous amounts of electricity needed to power to its aluminum smelting operations in Blount County. Superintendent I.G. Calderwood oversaw the extension of a railway line from Chilhowee to what is now Calderwood (railroad bridge support columns are still visible in the river just downstream from the dam). Southern Railway engineers had suggested that the construction of this rail line would take six months, but Calderwood and his team accomplished the task in just six weeks. [6] The first of Alcoa's Little Tennessee Valley dams, Cheoah, was completed in 1919, and the second, Santeetlah, was completed in 1928. [5] Preliminary work on Calderwood Dam began in 1918, but test drilling suggested the site might not be satisfactory. Subsequent tests confirmed the site's stability, however, and construction began in 1927. The first two generating units went into operation in 1930, and a third unit was added in 1938. [3]
The "cushion pool" design of Calderwood was influenced by natural cascade waterfall formations. The dam's arched-crest design may have been influenced by the design of Ocoee Dam No. 1, which was completed in 1911 along the Ocoee River a few miles to the south. Calderwood's use of a conduit tunnel to carry water to a powerhouse further downstream resembles the Great Falls Dam complex, completed in 1916 on the Caney Fork in Middle Tennessee. [5]
The community of Calderwood, Tennessee, located downstream from the dam and powerhouse, was developed in 1912 to house construction crews for Alcoa's Little Tennessee projects. This community was initially known as "Alcoa," but its name was changed to "Calderwood" in 1920 when the company reapplied its name to its main company town north of Maryville. [2] The Calderwood community grew to include nearly two dozen houses, two churches, a school, and a theater, but as construction and maintenance crews were no longer needed, the community was largely abandoned in the 1950s. Its houses were all razed, but the school and theater (now used as storage) were added to Calderwood Dam's National Register listing in 2004.
Blount County is a county located in the East Tennessee Grand Division of the U.S. state of Tennessee. As of the 2020 census, its population was 135,280. The county seat is Maryville, which is also the county's largest city. Blount County is included in the Knoxville metropolitan area.
The Little Tennessee River is a 135-mile (217 km) tributary of the Tennessee River that flows through the Blue Ridge Mountains from Georgia, into North Carolina, and then into Tennessee, in the southeastern United States. It drains portions of three national forests— Chattahoochee, Nantahala, and Cherokee— and provides the southwestern boundary of the Great Smoky Mountains National Park.
The Toccoa River and Ocoee River are the names in use for a single 93-mile-long (150 km) 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 County, Tennessee, near the town of Benton. Three power generating dams are operated along it.
Fort Loudoun Dam is a hydroelectric dam on the Tennessee River in Loudon County, Tennessee, in the southeastern United States. The dam is operated by the Tennessee Valley Authority (TVA), which built the dam in the early 1940s as part of a unified plan to provide electricity and flood control in the Tennessee Valley and create a continuous 652-mile (1,049 km) navigable river channel from Knoxville, Tennessee to Paducah, Kentucky. It is the uppermost of nine TVA dams on the Tennessee River.
Fontana Dam is a hydroelectric dam on the Little Tennessee River in Swain and Graham counties, North Carolina, United States. The dam is operated by the Tennessee Valley Authority, which built the dam in the early 1940s to satisfy the skyrocketing electricity demands in the Tennessee Valley to support the aluminum industry at the height of World War II; it also provided electricity to a formerly rural area.
Apalachia Dam is a hydroelectric dam on the Hiwassee River in Cherokee County, in the U.S. state of North Carolina. The dam is the lowermost of three dams on the river owned and operated by the Tennessee Valley Authority, which built the dam in the early 1940s to provide emergency power for aluminum production during World War II. While the dam is in North Carolina, an 8.3-mile (13.4 km) underground conduit carries water from the dam's reservoir to the powerhouse located 12 miles (19 km) downstream across the state line in Polk County, Tennessee. The dam and associated infrastructure were listed on the National Register of Historic Places in 2017.
The Cheoah Dam is a hydroelectric dam located in Graham and Swain counties, North Carolina, on the Little Tennessee River between river miles 51 and 52. The Cheoah Development consists of a dam and powerhouse, the first of several constructed by the Tallassee Power Company, a subsidiary of Aluminum Company of America, in order to generate electricity to smelt aluminum in Alcoa, Tennessee.
Santeetlah Dam is a hydroelectric dam on the Cheoah River in Graham County, North Carolina. It, a pipeline/tunnel facility, and a powerhouse form the Santeetlah Development. The Santeetlah powerhouse is located on the left bank of the Cheoah Reservoir portion of the Little Tennessee River five miles (8 km) upstream of the Cheoah Dam.
Chilhowee Dam is a hydroelectric dam located in Blount and Monroe counties, Tennessee, United States, between river mile 33 and 34 on the Little Tennessee River. Construction by the Tennessee Valley Authority (TVA) began in 1955 and was completed in 1957. The dam's reservoir covers approximately 1,734 acres (702 ha) at normal full pool and has a drainage area of 1,977 square miles (5,120 km2). The elevation of Chilhowee Reservoir is 874 feet (266 m) above mean sea level (USGS). Chilhowee's powerhouse is equipped with three Kaplan turbines that have a combined generating capacity of 48 megawatts.
Chilhowee was a prehistoric and historic Native American site in present-day Blount and Monroe counties in Tennessee, in what were the Southeastern Woodlands. Although now submerged by the Chilhowee Lake impoundment of the Little Tennessee River, the Chilhowee site was home to a substantial 18th-century Overhill Cherokee town. It may have been the site of the older Creek village "Chalahume" visited by Spanish explorer Juan Pardo in 1567. The Cherokee later pushed the Muscogee Creek out of this area.
Tallassee is a prehistoric and historic Native American site in present-day Blount and Monroe counties, Tennessee in the southeastern United States. Tallassee was the southernmost of a string of Overhill Cherokee towns that existed along the lower Little Tennessee River on the west side of the Appalachian Mountains in the 18th century. Although Tallassee receives scant attention in primary historical accounts, it is one of the few Overhill towns to be shown on every major 18th-century map of the Little Tennessee Valley.
Ocoee Dam Number 1 is a hydroelectric dam on the Ocoee River in Polk County in the U.S. state of Tennessee. The dam impounds the 1,930-acre (780 ha) Parksville Reservoir and is the farthest downstream of four dams on the Toccoa/Ocoee River owned and operated by the Tennessee Valley Authority. Completed in 1911, Ocoee No. 1 was one of the first hydroelectric projects in Tennessee.
Ocoee Dam Number 2 is a hydroelectric dam on the Ocoee River in Polk County in the U.S. state of Tennessee. The dam impounds the Ocoee No. 2 Reservoir and is one of three dams on the Toccoa/Ocoee River owned and operated by the Tennessee Valley Authority. It was completed in 1913.
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 3,300-acre (1,300 ha) Blue Ridge Lake on the southwestern fringe of the Blue Ridge Mountains.
Ocoee Dam No. 3 is a hydroelectric dam on the Ocoee River in Polk County, in the U.S. state of Tennessee. It is one of four dams on the Toccoa/Ocoee River owned and operated by the Tennessee Valley Authority, which built the dam in the early 1940s to meet emergency demands for electricity during World War II. The dam impounds the 360-acre (150 ha) Ocoee No. 3 Reservoir, which stretches 11 miles (18 km) upriver to the Tennessee-Georgia state line. Ocoee No. 3's powerhouse is actually located several miles downstream from the dam, and is fed by a 2.5-mile (4.0 km) conduit that carries water to it from the reservoir.
Nottely Dam is a hydroelectric and flood storage dam on the Nottely River in Union County, in the U.S. state of Georgia. The dam is owned and operated by the Tennessee Valley Authority, which built the dam in the early 1940s as a flood control structure and to help regulate flow at nearby Hiwassee Dam. The dam impounds the Lake Nottely of 4,180 acres (16.9 km2). While the dam was built primarily for flood storage, a generator was installed at Nottely in the 1950s, giving it a small hydroelectric output.
Chatuge Dam is a flood control and hydroelectric dam on the Hiwassee River in Clay County, in the U.S. state of North Carolina. The dam is the uppermost of three dams on the river owned and operated by the Tennessee Valley Authority, which built the dam in the early 1940s for flood storage and to provide flow regulation at Hiwassee Dam further downstream. The dam impounds the 7,000-acre (2,800 ha) Chatuge Lake, which straddles the North Carolina-Georgia state line. While originally built solely for flood storage, a generator installed at Chatuge in the 1950s gives the dam a small hydroelectric output. At the time it was built, Chatuge Dam was the highest earthen dam in the world until the Aswan Dam was built in Egypt in 1964. The dam and associated infrastructure was listed on the National Register of Historic Places in 2017.
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 stretch of the Upper Ocoee River was narrowed by two-thirds to create the drops and eddies needed for a slalom course. Today, the course is watered only on summer weekends, 34 days a year, for use by guided rafts and private boaters. When the river has water, 24 commercial rafting companies take more than 750 raft passengers through the course each day.
Calderwood was a community once located along the Little Tennessee River in Blount County, Tennessee, United States. Established in 1912 as a base for the Aluminum Company of America's Little Tennessee Valley hydroelectric development operations, the community continued to house construction personnel and dam maintenance personnel for nearby Calderwood Dam until the 1960s. Although the community's houses were razed after its abandonment, three buildings located in the community— the Calderwood Dam service building, the Calderwood School, and a Quonset hut used as a theater— were included in a supplementary listing for Calderwood Dam on the National Register of Historic Places in 2004.