Churchill Falls
Encyclopedia : C : CH : CHU : Churchill Falls
-->Churchill Falls are waterfalls, 245 ft (75 m) high, on the Churchill River in Labrador, Canada. Since 1970, the waters of the Churchill River have been diverted into the nearby Churchill Falls hydroelectric power station. Water flows down the falls less than once a decade, during spring thaw or periods of exceptional rains.
Churchill Falls were first explored 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.
The Churchill Falls power station has the second largest hydroelectric-generating capacity in North America (5,248 MW installed, expandable to about 6,300 MW) and is also the second largest underground power station in the world, after the Robert-Bourassa generating station in northern Quebec.
Four miles (6 km) above the falls, the Churchill River narrowed to 200 ft (60 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 miles (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).
Hydroelectic power project
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. 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 severals reasons:
- the inhospitable terrain
- severe climatic conditions
- geographic remoteness
- long distance transmission requirement
- the lack of markets for such a large block of power
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 feet (300 m) underground. Its final proportions are huge: in height it equals a 15-storey building, its length is three times that of a football field. When completed, it housed 11 generating units, with a combined capacity of 5,428 MW (more than 7,000,000 horsepower). 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 miles) 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 mi² (5,700 km²) and provides storage area for more than 1,000 million ft³ (28 million 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 mi² (60,300 km²). Once Orma and Sail lakes' outlets were diked, it added another 4,400 mi² (11,400 km²) of drainage for a total of 26,700 mi² (69,200 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 equaling 12.5 mi³ (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 and operated by the Newfoundland and Labrador Hydro company.
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 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 5,248 MW.
- 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 long, up to 81 ft wide and 154 ft high from the bottom to the top (296 m by 25 m by 47 m). The height would be equivalent to a 15 storey building, as long as 3 football fields and is hollowed from solid granite. To strengthen walls and ceiling, more then 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 2.3 million yd³ (1.9 million m³) of rock that was excavated from the underground caverns, it required 5 million pounds (2,300 tonnes) of explosives. 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 (70 tonnes) which is a world record for the largest stainless steel casting ever made.
- During construction, 730,000 short tons (660,000 tonnes) of material, equipment and fuel were moved to the site.
- The natural catchment area for the Churchill River covers over 23,300 mi² (60,300 km²).
- By diverting the water from the Ossokmanuan Reservoir the total catchment area became (26,700 mi² (69,200 m²).
- 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 (20 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 miles) and the highest is 36 m (117 ft). The total length of all dikes is 64 km (40 miles) and contains 26 million yd³ (22,000,000 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 2,100 MW dam at Gull Island, an 824 MW dam at Muskrat Falls, 1,000 MW 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 for a total of 9,252 MW for the entire Churchill River hydroelectric complex.
Specifications and statistics
Power station
Civil engineering
Churchill Falls Sport Fishing
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 and northern pike. The ideal growing environment leads to trout weighing in excess of 20 pounds, when caught, and northern pike of comparibly above average weights.
The community of Churchill Falls can be reached via the Trans-Labrador Highway from the community of Happy Valley/Goose Bay, a nearly 4 hour drive, barring road washouts and other mishaps. The long travel time means that most fishers will plan to stay at one of the local fishing and hunting lodges, or will make camping arrangements. To reduce the amount of food needed, campers will often eat the northern pike caught, and save the more desirable trout catch to take home.
Black bears are a concern in this area, as many visiting fishermen will clean and discard their fish entrails near the camping or boat launch areas.
The 240 km between Labrador City & Churchill Falls was driveable in 4 hours in July 2006, in an ordinary vehicle. The 290 km drive between Churchill Falls & Happy Valley-Goose Bay took 5 hours the same day, same vehicle. The Trans-Labrador Highway is drveable in an ordinary vehicle, but a truck/SUV is best.
See also
External links
- [Churchill Falls Hydroelectric project]
- [Satellite Photo of Churchill Falls]
- [Profile of the Innu people of Labrador]
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.