Nechako Reservoir
Nechako Reservoir is located in British Columbia
Nechako Reservoir
Nechako Reservoir
LocationBritish Columbia
Coordinates53°45′N 126°0′W / 53.750°N 126.000°W / 53.750; -126.000
Typehydroelectric reservoir
Primary inflowsNechako River
Primary outflowspenstock
Basin countriesCanada
Max. length140 mi (230 km)
Surface area890 km2 (340 sq mi)
Max. depth305 m (1,001 ft)
Surface elevation2,790 ft (850 m)
Sections/sub-basinsNorthern arm (Ootsa Lake, Whitesail Lake, Whitesail Reach) and south arm (Eutsuk Lake, Natalkuz Lake, Chedakuz Arm, Knewstubb Lake, Tetachuck Lake)

The Nechako Reservoir, sometimes called the Ootsa Lake Reservoir, is a hydroelectric reservoir in British Columbia, Canada that was formed by the Kenney Dam making a diversion of the Nechako River through a 16-km intake tunnel in the Kitimat Ranges of the Coast Mountains to the 890 MW Kemano Generating Station at sea level at Kemano to service the then-new Alcan aluminum smelter[1] at Kitimat. When it was constructed on the Nechako River in 1952, it resulted in the relocation of over 75 families.[1] It was one of the biggest reservoirs built in Canada until the completion of the Columbia Treaty Dams and the W.A.C. Bennett Dam that created Lake Williston. The water level may swing 10 feet between 2790 and 2800 feet.

The damming "linked the rivers and lakes of Ootsa, Intata, Whitesail, Chelaslie, Tetachuck, Tahtsa and Natalkuz into the reservoir with a surface area of over 90,000 hectares."[1] "The water of these lakes and rivers was diverted westward to the Pacific Ocean, instead of eastward to the Fraser River."[1]

The creation of the reservoir flooded the series of lakes which typified the upper Nechako basin and in the process rendered the Quanchus Range, which lies between the north and south arms of the reservoir, a virtual island. The names of lakes amalgamated into the reservoir are perpetuated as names for the various stretches of water. The north arm includes Ootsa Lake, Whitesail Lake, and Whitesail Reach, the south arm Eutsuk Lake, Natalkuz Lake, Chedakuz Arm, Knewstubb Lake, Tetachuck Lake and others. Because Ootsa Lake is the largest of the original lakes its name is sometimes used for the whole reservoir, though the official name remains Nechako Reservoir.

Tweedsmuir North Provincial Park and Protected Area and Entiako Provincial Park both border the reservoir.

Impact

Cheslatta Dakelh (Carrier)

For many generations, the shores of Ootsa Lake were home to the Cheslatta Carrier Nation. The flooding of Nechako Canyon destroyed their traditional hunting and fishing grounds and their homes.[1]

Salvage archaeology

In the late 1940s, University of British Columbia professor Charles Edward Borden shifted his attention toward urgent salvage archaeology in the Nechako Canyon after learning that ALCAN planned on flooding the Nechako Canyon to supply power for their smelter in Kitimat (known as Kemano I Project).[2] In 1951 Borden and his protégé, anthropology student, Wilson Duff located over 130 sites of importance to Cheslatta T'en history. They conducted more intensive investigations prior to the flooding of the area.[2] The damming triggered "devastating changes for First Nations communities whose traditional territories lay in their path, including the destruction of Aboriginal gravesites, territories, livelihoods, and archaeological sites."[2] In 1957, Alcan opened the gate of the spillway to Skin's Lake desecrating Cheslatta graves, which came to public attention during the Royal Commission on Aboriginal Peoples.[3]

Kemano Completion Project

In the 1970s, Alcan proposed expanding the generating capacity at their Kemano Powerhouse by diverting more water from the Nechako Reservoir. At that time, it was envisioned that no additional dams would be required, and there would be no additional flooding. However, the project faced challenges and was ultimately canceled by the Provincial Government in 1995 due to significant environmental concerns related to the Nechako River.

Recent developments indicate that efforts were made to address the energy needs while considering environmental impacts. A second power tunnel between the reservoir and the powerhouse was planned for this purpose. It was intended to serve as a backup to the original tunnel, enhancing the sustainability of the project. In December 2017, there was a significant development when the US-$473 million Kemano second tunnel project received the go-ahead, as reported by the Kitimat Northern Sentinel. This project likely aimed to improve the efficiency and reliability of power generation while mitigating environmental impacts, in line with contemporary environmental standards and regulations.

However, it is essential to note that the completion date for this project was scheduled for 2020, according to available information. Therefore, the status and outcomes of this project beyond that date might require further investigation to provide the most up-to-date information.

Please note that the "out-of-date" template remains in place to indicate the need for further updates and verification of the project's status beyond May 2023.[4]

Climate

Tahtsa Lake is at the far western end of Nechako Reservoir and has a subarctic climate (Köppen Dfc), with high levels of precipitation and snowfall.

Climate data for Tahtsa Lake West, BC (1981-2010):863m
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 10.5
(50.9)
13.9
(57.0)
14.0
(57.2)
21.1
(70.0)
30.0
(86.0)
28.3
(82.9)
31.7
(89.1)
33.0
(91.4)
27.8
(82.0)
22.0
(71.6)
12.8
(55.0)
10.6
(51.1)
33.0
(91.4)
Mean daily maximum °C (°F) −2.3
(27.9)
−0.7
(30.7)
3.4
(38.1)
7.0
(44.6)
11.1
(52.0)
14.6
(58.3)
17.6
(63.7)
17.8
(64.0)
13.9
(57.0)
6.8
(44.2)
0.7
(33.3)
−1.9
(28.6)
7.3
(45.2)
Daily mean °C (°F) −5.5
(22.1)
−4.7
(23.5)
−1.5
(29.3)
1.7
(35.1)
5.2
(41.4)
8.6
(47.5)
11.8
(53.2)
11.8
(53.2)
8.4
(47.1)
3.2
(37.8)
−2.2
(28.0)
−4.8
(23.4)
2.7
(36.8)
Mean daily minimum °C (°F) −8.7
(16.3)
−8.8
(16.2)
−6.4
(20.5)
−3.5
(25.7)
−0.8
(30.6)
2.6
(36.7)
5.9
(42.6)
5.8
(42.4)
2.8
(37.0)
−0.5
(31.1)
−5.0
(23.0)
−7.7
(18.1)
−2.0
(28.4)
Record low °C (°F) −35.6
(−32.1)
−35.0
(−31.0)
−31.7
(−25.1)
−19.4
(−2.9)
−6.7
(19.9)
−2.0
(28.4)
−6.1
(21.0)
−6.1
(21.0)
−20.0
(−4.0)
−26.0
(−14.8)
−30.0
(−22.0)
−32.2
(−26.0)
−35.6
(−32.1)
Average precipitation mm (inches) 267.3
(10.52)
202.4
(7.97)
134.6
(5.30)
94.1
(3.70)
75.1
(2.96)
64.9
(2.56)
51.4
(2.02)
74.4
(2.93)
155.2
(6.11)
281.9
(11.10)
295.1
(11.62)
288.3
(11.35)
1,984.7
(78.14)
Average snowfall cm (inches) 200.9
(79.1)
165.5
(65.2)
101.8
(40.1)
45.4
(17.9)
9.0
(3.5)
0.2
(0.1)
0.0
(0.0)
0.0
(0.0)
0.6
(0.2)
40.0
(15.7)
186.5
(73.4)
225.8
(88.9)
975.7
(384.1)
Source: Environment Canada[5]

Wistaria is on the northern shore of Nechako Reservoir, about 85km east of Tahtsa Lake. Wistaria also has a subarctic climate (Köppen Dfc), but it receives far less precipitation and snowfall.

Climate data for Wistaria, BC (1981-2010): 863m
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 11.1
(52.0)
12.8
(55.0)
18.3
(64.9)
26.7
(80.1)
35.6
(96.1)
32.8
(91.0)
36.1
(97.0)
35.6
(96.1)
33.9
(93.0)
24.4
(75.9)
18.0
(64.4)
11.5
(52.7)
36.1
(97.0)
Mean daily maximum °C (°F) −4.1
(24.6)
−1.4
(29.5)
3.3
(37.9)
8.5
(47.3)
13.2
(55.8)
17.2
(63.0)
19.6
(67.3)
19.8
(67.6)
15.6
(60.1)
8.3
(46.9)
1.0
(33.8)
−3.0
(26.6)
8.2
(46.7)
Daily mean °C (°F) −7.9
(17.8)
−6.2
(20.8)
−2.1
(28.2)
2.7
(36.9)
7.2
(45.0)
11.2
(52.2)
13.5
(56.3)
13.4
(56.1)
9.5
(49.1)
4.0
(39.2)
−2.1
(28.2)
−6.3
(20.7)
3.1
(37.5)
Mean daily minimum °C (°F) −11.6
(11.1)
−11.1
(12.0)
−7.6
(18.3)
−3.1
(26.4)
1.1
(34.0)
5.2
(41.4)
7.4
(45.3)
6.9
(44.4)
3.5
(38.3)
−0.4
(31.3)
−5.2
(22.6)
−9.5
(14.9)
−2.0
(28.3)
Record low °C (°F) −43.9
(−47.0)
−40.6
(−41.1)
−36.1
(−33.0)
−25.6
(−14.1)
−9.4
(15.1)
−4.4
(24.1)
−2.8
(27.0)
−3.3
(26.1)
−10.0
(14.0)
−23.5
(−10.3)
−35.5
(−31.9)
−41.7
(−43.1)
−43.9
(−47.0)
Average precipitation mm (inches) 38.5
(1.52)
25.5
(1.00)
20.5
(0.81)
16.7
(0.66)
32.3
(1.27)
54.0
(2.13)
42.3
(1.67)
38.0
(1.50)
41.4
(1.63)
40.3
(1.59)
43.7
(1.72)
39.5
(1.56)
432.7
(17.06)
Average snowfall cm (inches) 32.5
(12.8)
23.0
(9.1)
18.8
(7.4)
6.1
(2.4)
2.5
(1.0)
0.0
(0.0)
0.0
(0.0)
0.0
(0.0)
0.1
(0.0)
9.4
(3.7)
30.2
(11.9)
34.8
(13.7)
157.4
(62)
Source: Environment Canada[6]

See also

Citations

  1. 1 2 3 4 5 Heritage British Columbia 2009.
  2. 1 2 3 Roy 2010, p. 127.
  3. Roy 2010, p. 128.
  4. "US-$473 million Kemano second tunnel project gets the go-ahead - Kitimat Northern Sentinel". northernsentinel.com. 13 December 2017. Retrieved 13 April 2018.
  5. "Tahtsa Lake West, BC". Canadian Climate Normals 1981–2010 (in English and French). Environment Canada. 25 September 2013. Retrieved August 31, 2023.
  6. "Wistaria, BC". Canadian Climate Normals 1981–2010 (in English and French). Environment Canada. 31 October 2011. Retrieved August 31, 2023.

References

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