La Grande River (French: La Grande Rivière; Cree: Chisasibi; both meaning "great river") is a river in northwestern Quebec, Canada, rising in the highlands of the north-central part of the province and flowing roughly 900 km (560 mi) west to its drainage at James Bay. It is the second-longest river in the province, surpassed only by the Saint Lawrence River.

La Grande River
La Grande River near Radisson, Quebec
La Grande River original basin in yellow. Diverted basins in orange.
Location
CountryCanada
ProvinceQuebec
RegionJamésie
Physical characteristics
SourceLac Nichicun
 • locationNitchequon
 • coordinates53°12′30″N 70°56′00″W / 53.20833°N 70.93333°W / 53.20833; -70.93333
MouthJames Bay
 • location
Chisasibi
 • coordinates
53°50′00″N 79°04′00″W / 53.83333°N 79.06667°W / 53.83333; -79.06667
 • elevation
0 m (0 ft)
Length893 km (555 mi)[1]
Basin size97,600 km2 (37,700 sq mi)[1]
Discharge 
 • average3,400 m3/s (120,000 cu ft/s)[2]
 • minimum345 m3/s (12,200 cu ft/s)
 • maximum4,450 m3/s (157,000 cu ft/s)

Originally, the La Grande River drained an area of 97,400 km2 (37,600 sq mi), and had a mean discharge of 1,690 m3/s (60,000 cu ft/s).[1] Since the 1980s, when hydroelectric development diverted the Eastmain and Caniapiscau rivers into the La Grande, its total catchment area has increased to about 175,000 km2 (68,000 sq mi), with its mean discharge being more than 3,400 m3/s (120,000 cu ft/s).[2] In November 2009, the Rupert River was also (partially) diverted, adding another 31,430 km2 (12,140 sq mi) to the basin.

At one time, the La Grande was known as the "Fort George River". The Hudson's Bay Company operated a trading post on the river, at Big River House, between 1803 and 1824. In 1837, a larger trading post was established at Fort George, on an island at the mouth of the river. In the early 20th century, this trading post became a village as the Crees of the James Bay region abandoned their nomadic way of life and settled nearby. The modern Cree village of Chisasibi, which replaced Fort George in 1980, is situated on the southern shore of the La Grande River, several kilometers to the East.

Tributaries edit

Significant tributaries of La Grande River include:

Hydro-electric development edit

The river has been extensively developed as a source of hydroelectric power by Hydro-Québec, starting in 1974. An area of 9,900 km2 (3,800 sq mi) was flooded[citation needed] and almost all of the flow of the Eastmain River[citation needed] and approximately 70% of the flows of the Rupert River[3][4] were diverted into the La Grande watershed. The following generating stations are on the La Grande River and its tributaries in upstream order:

As a result of the development projects, the Cree people of the region lost some parts of their traditional hunting and trapping territories (about 10%[citation needed] of the hunting and trapping territories used by the Cree of Chisasibi). Organic mercury levels increased in the fish, which forms an important part of their diet, as the organic material trapped by the rising waters in the new reservoirs began to filter into the food chain. Careful follow-up by Cree health authorities since the 1980s has been largely successful. The authorities continue to promote the regular consumption of fish, with the notable exception of the predatory species living in the reservoirs, which still show high levels of mercury.[citation needed]

Climate edit

Climate data for La Grande Rivière (La Grande Rivière Airport)
WMO ID: 71827; coordinates 53°38′N 77°42′W / 53.633°N 77.700°W / 53.633; -77.700 (La Grande Rivière Airport); elevation: 195.1 m (640 ft); 1981–2010 normals
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high humidex 1.8 4.8 11.1 21.8 33.9 37.5 44.3 35.5 31.6 28.3 11.7 7.6 44.3
Record high °C (°F) 1.4
(34.5)
5.0
(41.0)
11.3
(52.3)
22.3
(72.1)
32.6
(90.7)
35.0
(95.0)
37.3
(99.1)
31.2
(88.2)
27.1
(80.8)
23.5
(74.3)
12.3
(54.1)
7.4
(45.3)
37.3
(99.1)
Mean daily maximum °C (°F) −18.5
(−1.3)
−15.9
(3.4)
−8.2
(17.2)
0.6
(33.1)
10.3
(50.5)
17.3
(63.1)
20.4
(68.7)
18.6
(65.5)
12.3
(54.1)
4.8
(40.6)
−3.1
(26.4)
−12.0
(10.4)
2.2
(36.0)
Daily mean °C (°F) −23.2
(−9.8)
−21.6
(−6.9)
−14.5
(5.9)
−5.0
(23.0)
4.3
(39.7)
10.8
(51.4)
14.2
(57.6)
13.1
(55.6)
8.1
(46.6)
1.7
(35.1)
−6.1
(21.0)
−16.0
(3.2)
−2.9
(26.8)
Mean daily minimum °C (°F) −28.0
(−18.4)
−27.3
(−17.1)
−20.7
(−5.3)
−10.6
(12.9)
−1.6
(29.1)
4.2
(39.6)
8.0
(46.4)
7.6
(45.7)
3.8
(38.8)
−1.5
(29.3)
−9.1
(15.6)
−19.9
(−3.8)
−7.9
(17.8)
Record low °C (°F) −40.9
(−41.6)
−44.6
(−48.3)
−39.7
(−39.5)
−31.4
(−24.5)
−14.4
(6.1)
−6.6
(20.1)
−0.9
(30.4)
−0.5
(31.1)
−7.0
(19.4)
−16.7
(1.9)
−29.2
(−20.6)
−40.3
(−40.5)
−44.6
(−48.3)
Record low wind chill −56 −57 −51 −40 −24 −12 −3 −6 −10 −20 −40 −53 −57
Average precipitation mm (inches) 30.9
(1.22)
21.9
(0.86)
29.4
(1.16)
32.7
(1.29)
39.0
(1.54)
65.3
(2.57)
78.5
(3.09)
91.1
(3.59)
110.6
(4.35)
87.3
(3.44)
67.9
(2.67)
42.6
(1.68)
697.2
(27.45)
Average rainfall mm (inches) 0.1
(0.00)
1.2
(0.05)
3.4
(0.13)
12.7
(0.50)
27.9
(1.10)
62.6
(2.46)
78.5
(3.09)
91.0
(3.58)
106.9
(4.21)
56.2
(2.21)
11.6
(0.46)
1.7
(0.07)
453.8
(17.87)
Average snowfall cm (inches) 33.1
(13.0)
23.0
(9.1)
28.6
(11.3)
21.0
(8.3)
11.9
(4.7)
2.6
(1.0)
0.0
(0.0)
0.1
(0.0)
4.0
(1.6)
32.4
(12.8)
60.3
(23.7)
44.4
(17.5)
261.3
(102.9)
Average precipitation days (≥ 0.2 mm) 16.3 12.5 11.9 10.8 12.1 12.4 14.1 16.2 20.2 20.6 22.0 19.7 188.9
Average rainy days (≥ 0.2 mm) 0.33 0.67 1.10 4.00 8.00 11.60 14.00 16.30 19.50 12.70 4.10 0.84 92.90
Average snowy days (≥ 0.2 cm) 16.4 12.3 11.5 8.5 5.7 1.6 0.04 0.04 1.9 11.8 20.5 19.6 109.8
Average afternoon relative humidity (%) (at 15:00) 73.1 68.3 60.3 57.9 53.1 50.3 54.7 59.6 68.9 75.8 83.5 80.3 65.5
Source: Environment and Climate Change Canada[5]


See also edit

References edit

  1. ^ a b c Atlas of Canada Archived 2007-04-10 at the Wayback Machine (all values of original river prior to hydro-electric development.)
  2. ^ a b Hydro-Québec and GENIVAR Groupe Conseil inc., Environmental Monitoring of the La Grande-2-A and La Grande-1 Projects. Abridged Summary Report 1987-2000. La Grande Winter plume. July 2005 (Online version Archived 2011-06-05 at the Wayback Machine)
  3. ^ DeSILVA, BRUCE (1989-01-15). "'Caught Between Two Worlds' : Modern Man's Encroachment in Quebec Forever Alters Cree Way of Life : Quebec Dams Evict Tribe From Home". Los Angeles Times. Retrieved 2023-03-13.
  4. ^ Bell, Susan (3 June 2017). "Stories from the trenches: Adapting a Cree way of life in the wake of a mega-project". CBC.
  5. ^ "Canadian Climate Normals 1981-2010 Station Data". Environment and Climate Change Canada. Retrieved March 6, 2022.

External links edit