Natural Resource Stewardship
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The Kenney Dam, which impounds the waters of the Nechako Reservoir. |
Overview
Hydroelectricity generation extends the impacts of Rio Tinto Alcan operations over a much broader geographic area than that potentially impacted by aluminum production itself.
Hydroelectric generation typically relies on dams and water storage, and entails the careful management of water releases and diversions, and of downstream impacts on biodiversity and other natural values. Stewardship expectations are therefore particularly high.
Strategies and Initiatives
Reservoir Management: Rio Tinto Alcan Primary Metal BC’s single largest natural-resource stewardship responsibility relates to managing the approximately 90,000-hectare chain of lakes that makes up the Nechako Reservoir in north-central British Columbia.
The reservoir is a significant ecological feature, and releases from its Skins Lake spillway flow through the Cheslatta system, into the Nechako River and then into the Fraser River. Changes in reservoir releases are managed to minimize impacts to downstream fish habitat and other fisheries, wildlife, commercial, residential and recreational values.
Releases are managed in accordance with the 1987 agreement with the federal and provincial governments. It establishes a hierarchy of objectives, minimum flows, and targets relating to fish and habitat conditions, and is administered through the Nechako Fisheries Conservation Program (NFCP).
One such target relates to Chinook salmon returning to spawn in the Nechako River. 2007 was one of four years in the last nineteen when estimates fell below the targeted range.
Numbers in the relevant brood year (five years earlier) were strong, and monitoring has not indicated in-river habitat changes since. The NFCP therefore believes this decline relates to ocean-survival factors, rather than to conditions in the Nechako River.
Another target relates to water temperatures during the July 20 to August 20 period when adult Sockeye salmon migrate through the Nechako River en route to their spawning grounds. Because of high precipitation during 2007, and resulting high water releases from the Nechako Reservoir (see "Power Ops and Reservoir Management"), water temperatures in 2007 were kept below the upper limit specified by the NFCP.
White Sturgeon: Rio Tinto Alcan Primary Metal BC participates in and is a major sponsor of the Nechako White Sturgeon Recovery Initiative. Nechako white sturgeon are believed to be the most endangered of four genetically distinct populations in British Columbia that were recently protected under federal species-at-risk legislation.
Rio Tinto Alcan Primary Metal BC provided $220,000 and in-kind support in 2007 for research and the operation of a pilot white sturgeon hatchery at Vanderhoof. Some 4,500 juvenile white sturgeon were released from the hatchery in the fall.
Coastal Waters: Water diverted from the Nechako Reservoir for power generation is released into the Kemano River, and accounts for 45-95 per cent of its flow. The operation of a flow control program is designed to avoid impacts on eulachon habitat during the springtime period when they typically spawn and rear in the Kemano River.
While the numbers of returning eulachon have fluctuated widely in the past, 2007 marked the third consecutive year of extremely low returns, and this is outside the historic norm. This phenomenon has also occurred in other coastal rivers within the same timeframe, suggesting causes that do not relate to in-river conditions.
While Rio Tinto Alcan Primary Metal BC operations are not believed to be a contributing factor to the eulachon’s decline, there is ongoing collaboration on monitoring and management with the Haisla First Nation, for whose members the fish is an important part of their traditional diet and of great cultural significance.
Land-Based Stewardship: In addition to water-related stewardship responsibilities, Rio Tinto Alcan Primary Metal BC has significant landholdings in the vicinity of the Nechako Reservoir. This area is at the epicentre of the mountain pine beetle epidemic that has killed large swathes of pine forest in British Columbia.
During 2007, a final beetle-control harvest was carried out on some company lands, as part of the Three Nations Forest Stewardship Initiative. Initiated in 2004, this is a project through which Rio Tinto Alcan Primary Metal BC supported forestry-related capacity building and revenue generation for three First Nations, and contracted them to conduct harvesting and silviculture.
| Water Use By Source, 2007 | |
| Surface Water – Diverted from Kitimat River and Anderson Creek to Kitimat Smelter |
12,000,000 m3 (estimated) |
| Ground Water – Well Water for Non-Generating Use at Kemano |
2,870 m3 (estimated) |
| Total | 12,002,870 m3 |
49.7 m3 per Tonne of Aluminum Production (2006=54.1 m3)
Rio Tinto Alcan Primary Metal BC also diverts saltwater into its effluent treatment lagoons as a toxicity-control measure. Amounts vary in proportion to precipitation and lagoon outflows and are returned to the marine environment. These volumes are not directly measured, and are not included in the above totals. The figures above also exclude water diverted from the Nechako Reservoir for power generation, which is released into the Kemano River.
