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Churchill Falls

 
Dictionary: Churchill Falls


A waterfall, 74.7 m (245 ft) high, of the upper Churchill River in southwest Labrador, Canada. There is a hydroelectric power plant at the falls.

 

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Britannica Concise Encyclopedia: Churchill Falls
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Part of a series of cataracts and rapids on the Churchill River, Newfoundland, Canada. The falls drop 245 ft (75 m) and are 200 ft (60 m) wide. They power one of Canada's largest hydroelectric stations. Visited in 1839 by John McLean of the Hudson's Bay Company, the cataracts were called Grand Falls until 1965, when both falls and river were renamed for Winston Churchill, who died that year.

For more information on Churchill Falls, visit Britannica.com.

 
Columbia Encyclopedia: Churchill Falls
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Churchill Falls, spectacular waterfalls of the upper Churchill River, 245 ft (75 m) high, SW Labrador, N.L., Canada; known as Grand Falls until renamed (1965) in honor of Sir Winston Churchill. The falls were first explored (1839) by John McLean, a trader of the Hudson Bay Company. Four miles (6.4 km) above the falls, the Churchill River narrows to 200 ft (61 m) and negotiates a series of rapids before dropping into McLean Canyon, from which sheer cliffs rise several hundred feet on either side. The river flows 12 mi (19 km) through the canyon over a series of rapids. The total drop from the rapids above the main falls to the end of McLean Canyon is 1,038 ft (316 m). Because of their isolated location and harsh surroundings, the falls never became a tourist attraction. Churchill Falls has one of the largest hydroelectricity-generating capacities (5,225,000 kW) in the world. It was completed in 1974 and most of the power is sent to the Montreal vicinity.


Wikipedia: Churchill Falls
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Churchill Falls
Churchillfallslabrador2.jpg
Location Labrador
Coordinates 53°36′00″N 64°18′57″W / 53.6°N 64.31583°W / 53.6; -64.31583[1]
Type Segmented Block
Total height 245 ft (75 m)
Watercourse Churchill River

Churchill Falls are waterfalls named after former British Prime Minister, Winston Churchill. They are 245 ft (75 m) high, located on the Churchill River in Newfoundland and Labrador, Canada.

4 mi (6.4 km) above the falls, the Churchill River narrowed to 200 ft (61 m) and negotiated a series of rapids before dropping into MacLean Canyon, from which sheer cliffs rise several hundred feet on either side. The river flowed 12 mi (19 km) through the canyon over a series of rapids. The total drop from the rapids above the main falls to the end of MacLean Canyon is 1,038 ft (316 m).

Since 1970, the waters of the Churchill River have been diverted into the nearby Churchill Falls hydroelectric power station. Today water flows down the falls less than once a decade, during spring thaw or periods of exceptional rains. The Churchill Falls power station has the second largest hydroelectric-generating capacity in North America (5,428 MW (7,279,000 hp) installed, expandable to about 6,300 MW (8,400,000 hp)) and is also the second largest underground power station in the world, after the Robert-Bourassa generating station in northern Quebec.

Contents

Discovery and study

Churchill Falls were first explored by Europeans in 1839 by John McLean, a trader of the Hudson's Bay Company. MacLean named the river the Hamilton River, after Newfoundland Governor, Sir Charles Hamilton. The falls were known as Grand Falls until 1965 when both names were changed to the Churchill River and Churchill Falls to honour the former British Prime Minister, Sir Winston Churchill.

In 1894, Albert Peter Low of the Geological Survey of Canada reached the Grand Falls during his study of the large number of iron ore deposits in western Labrador and northeastern Quebec.

Hydroelectric power project

Churchill Falls as it appeared in 2008, four decades after the water was redirected.

In 1915, Wilfred Thibaudeau surveyed the Labrador Plateau and engineered a channel scheme which could be used to divert the water from the river before it arrived at the falls. The scheme would use the natural capacity of the basin, thereby eliminating the need for the construction of massive dams.

In 1947, Commander G.H. Desbarats, under the direction of the Newfoundland Government, completed a preliminary survey that confirmed Thibaudeau's findings. However development did not proceed due to several reasons:

  1. the inhospitable terrain
  2. severe climatic conditions
  3. geographic remoteness
  4. long distance transmission requirement
  5. the lack of markets for such a large block of power

In August, 1949, Joey Smallwood, Premier of Newfoundland, had the opportunity to see Churchill Falls for the first time and it became his obsession to develop the hydroelectric potential of the falls. In 1953 British Newfoundland Development Corporation (Brinco) was formed to do extensive exploration of the untapped water and mineral resources. With the development of the iron ore mines in western Labrador and the construction of the Quebec North Shore and Labrador Railway (1954), development of Churchill Falls as a power source became feasible.

After years of planning, the project was officially started on July 17, 1967. The machine hall of the power facility at Churchill Falls was hollowed out of solid rock, close to 1,000 ft (300 m) underground. Its final proportions are huge: in height it equals a 15-storey building, its length is three times that of a Canadian football field. When completed, it housed 11 generating units, with a combined capacity of 5,428 MW (7,279,000 hp). Water is contained by a reservoir created not by a single large dam, but by a series of 88 dikes that total 64 km (40 mi) in length.

Once all the dikes were in place, it provided a vast storage area which later became known as Smallwood Reservoir. This reservoir covers 2,200 sq mi (5,700 km2) and provides storage area for more than 1,000,000,000,000 cubic feet (2.8×1010 m3) of water.

The drainage area for the Churchill River includes much of western and central Labrador. Ossokmanuan Reservoir which was originally developed as part of the Twin Falls Power System also drains into this system. Churchill River's natural drainage area covers over 23,300 sq mi (60,000 km2). Once Orma and Sail lakes' outlets were diked, it added another 4,400 sq mi (11,000 km2) of drainage for a total of 27,700 sq mi (72,000 km2). This makes the drainage area larger than the Republic of Ireland. Studies showed this drainage area collected 410 mm (16 in) of rainfall plus 391 cm (154 in) of snowfall annually equalling 12.5 cu mi (52 km3) of water per year; more than enough to meet the project's needs. Construction came to fruition on December 6, 1971, when Churchill Falls went into full-time production.

The generating station is owned by the Churchill Falls (Labrador) Corporation Ltd. — whose shareholders are Nalcor (65.8%) and Hydro-Québec (34.2%) —[2] and operated by the Newfoundland and Labrador Hydro company.

The division of profits from the sale of electricity generated at the plant have proven to be a very sensitive political issue in Newfoundland and Labrador, with many considering the share accorded to Hydro-Québec "an immense and unconscionable windfall."[3]

The people of Quebec considered the inland watershed of Labrador to be part of their province, and fought a long but losing legal battle to prevent granting the territory to Newfoundland. [4]

Aboriginal rights

The Churchill Falls hydroelectric plant development was undertaken in the absence of any agreement with the aboriginal Innu people of Labrador. Despite the flooding of over 5,000 km2 (1,900 sq mi) of traditional hunting and trapping lands, no compensation was ever offered.

Project facts

  • Churchill Falls power plant is the second largest hydroelectric plant in North America, with an installed capacity of 5,428 MW (7,279,000 hp).
  • Churchill Falls was, at the time of its construction, the largest underground power station in the world. (The Robert-Bourassa power station in Quebec currently holds the record, both for installed capacity and volume of the main underground hall).
  • The powerhouse is 972 ft (296 m) long, up to 81 ft (25 m) wide and 154 ft (47 m) high from the bottom to the top. The height would be equivalent to a 15-storey building or almost as long as three Canadian football fields (990 ft (300 m) and is hollowed from solid granite. To strengthen walls and ceiling, more than 11,000 rock bolts (steel rods 15 to 25 ft (5 to 8 m) long) were used in the three major chambers.
  • To move the 2,300,000 cu yd (1,760,000 m3) of rock that was excavated from the underground caverns, it required 5,000,000 lb (2,300,000 kg). This material was used in roads, building the town site, and as dike material.
  • The turbine wheels are cast of stainless steel and weigh 80 short tons (73 t) which is a world record for the largest stainless steel casting ever made.
  • During construction, 730,000 short tons (660,000 t) of material, equipment and fuel were moved to the site.
  • The natural catchment area for the Churchill River covers over 23,300 sq mi (60,000 km2).
  • By diverting the water from the Ossokmanuan Reservoir the total catchment area became 27,700 sq mi (72,000 km2).
  • Total natural drop of the water starting at Ashuanipi Lake and ending at Lake Melville is 1,735 ft (529 m). As a comparison, the water starting 30 km (19 mi) upriver until it enters the power plant drops over 1,000 ft (300 m).
  • There is no big dam associated with this hydropower plant. There are 88 dikes to contain the reservoir, the longest is 6.1 km (3.8 mi) and the highest is 36 m (120 ft). The total length of all dikes is 64 km (40 mi) and contains 26,000,000 cu yd (20,000,000 m3) of embankment material.
  • After five years of non-stop field work by approximately 6,300 workers and costing $950,000,000 (1970) construction culminated on December 6, 1971 when the first two generating units began delivering power, five months and three weeks ahead of schedule.
  • Currently Churchill Falls makes almost 1% of the world's hydroelectric power.
  • Newfoundland and Labrador recently announced a call to develop the Lower Churchill Project. This is, in fact, a number of small projects which includes a 2,000 MW (2,700,000 hp) dam at Gull Island, an 824 MW (1,105,000 hp) dam at Muskrat Falls, 1,000 MW (1,300,000 hp) upgrade to the existing facility at the Churchill Falls power plant. This would increase the present power production capability by an extra 4,000 MW (5,400,000 hp) for a total of 9,252 MW (12,407,000 hp) for the entire Churchill River hydroelectric complex.

Specifications and statistics

Power station

Churchill Falls generating station
Year commissioned: 1971
Installed capacity: 5,428 MW (7,279,000 hp)
Annual energy output: 35,000 GWh (130,000 TJ)
Number of turbines: 11
Turbine capacity: 493.5 MW (661,800 hp)
Type of turbine: vertical Francis type, 200 rpm
Generators: 15 kV, 526,315 kV·A
Transformers: 14.75 kV/240 kV, rated at 5,500 MV·A
Net rated head: 312.4 m (1,025 ft)
Maximum tailrace discharge: 49,000 ft³/s (1,390 m³/s)
Powerhouse: 296 m (970 ft) length, 25 m (82 ft) width, 47 m (150 ft) height, 310 m (1,000 ft) below ground
Tailrace tunnels: 2 × 1,691 m (5,550 ft), 14 m (46 ft) width, 19 m (62 ft) height
Penstocks: 11 × 427 m (1,400 ft) length, 20 ft (6.1 m) diameter
Cable shafts: 11 × 7 ft (2.13 m) diameter, 263 m (860 ft) deep
Dikes: 88; 64.4 km (40.0 mi) total length, 9 m (30 ft) average height, 36 m (120 ft) maximum height
Size of reservoir: 6,988 km2 (2,698 sq mi)
Total catchment area: 71,700 km2 (27,700 sq mi)

Sport fishing

14 pound lake trout caught in the Churchill Falls reservoir lakes.

The community of Churchill Falls has been a popular destination for hobby and sport fisherman for many years. The construction of the hydroelectric infrastructure has created large, enclosed freshwater environments which are populated by several species of fish, including lake trout, brook trout (speckled trout) and northern pike. The ideal growing environment leads to lake trout some weighing in at 50 pounds 50 lb (23 kg), speckled trout larger than 6 lb (2.7 kg), and northern pike of above average weights.

References

  1. ^ "GeoNames Query - Churchill Falls: Query Record Details". Natural Resources Canada. Government of Canada. 2008-11-09. http://geonames2.nrcan.gc.ca/cgi-bin/v9/sima_unique_v9?english?ABGAE?C. Retrieved 2008-11-09. 
  2. ^ Supreme Court of Canada (1984-05-03). "Reference re Upper Churchill Water Rights Reversion Act, (1984) 1 S.C.R. 297". CanLII. http://csc.lexum.umontreal.ca/en/1984/1984rcs1-297/1984rcs1-297.html. Retrieved 2009-04-09. 
  3. ^ Why the Churchill Falls Agreement Must be Re-Negotiated
  4. ^ Labrador Boundary Dispute

See also

External links

Coordinates: 53°31′30″N 63°58′40″W / 53.525°N 63.97778°W / 53.525; -63.97778


 
 

 

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Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
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Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Churchill Falls" Read more