Cheakamus – Water Use Plan

Citation:

BC Hydro. (2005). Cheakamus Project Water Use Plan. Vancouver: BC Hydro.

PDF Link:

Summary:

The Cheakamus WUP is typical of the early WUPs, with one exception: of the 23 completed, it is the only non-consensus WUP.

The Cheakamus watershed is in the Squamish-Lillooet Regional District, between the communities of Whistler to the north and Brackendale to the south. It is entirely within the traditional territory of the Squamish Nation. The Cheakamus River provides spawning and rearing habitat for several salmon species and also is a large fall and winter congregation area for bald eagles that feed on salmon carcasses. The river also provides rafting, kayaking, and sport fishing opportunities.

From its very beginnings in the early 1950s, the development of the Cheakamus facilities was opposed by local residents and fisheries agencies.

Objections to the project were eventually withdrawn when the comptroller of water rights inserted a clause into the water licence allowing for the order of release of water for fish. Concerns about flows for fish persisted for decades.

The Cheakamus generating system consists of the Daisy Lake dam and reservoir on the Cheakamus River and the Cheakamus powerhouse in the Squamish Valley, 10 km northwest of Brackendale. Water is diverted out of the Cheakamus River at the Daisy Lake dam into a canal under the Sea-to-Sky highway, where it enters an 11-km tunnel through Cloudburst Mountain. Two penstocks carry it down to the twin turbines of the Cheakamus generating station, where it then discharges into the Squamish River. Maximum flow through the generating station is 65 m³/second, with a total maximum head of 340 m. The powerhouse’s installed capacity is 157 megawatts. Approximately 75% of the total flow of the Cheakamus River originates upstream of the Daisy Lake dam.

Public consultation began on the WUP in February 1999 with a 20-member CC, including the Squamish Nation, following the provincial water use planning guidelines. The CC identified objectives for power, First Nations, recreation, flooding, fish, and aquatic ecosystems, and agreed on performance measures for each. The consultation was completed in April 2002 after 25 CC meetings, with a failure to reach consensus.

Consensus was not reached because half of the CC members at the end of the process felt that the performance measures were insufficient, due to the fact that engineered side channels had been built and were not being adequately recognized as fish habitat. This issue emerged late in the process, which led to some frustration in the committee. DFO had constructed the side channels to work in the pre-interim-flow period, and they had been designed to work in a low-flow time. However, eight of the 16 members preferred the higher flows in the main channel, which also resulted in higher flows in the side channels to provide the maximum amount of fish habitat. They wanted to continue to monitor the interim flows for another three to five years to provide additional information to thoroughly assess effects. The other half of the CC, including representatives of BC Hydro, DFO, and the Ministry of Energy and Mines, accepted the performance measures and based their support on the outcomes depicted by the computer modelling. They favoured lower flows as providing the greatest amount of main-channel fish habitat, and they also argued that these flows provided adequate flow in the side channels, which had been designed to function in a lower-flow state. As BC Hydro was not able to obtain a consensus on this issue, they drafted a non-consensus WUP in accordance with the guidelines and submitted it to the comptroller of water rights. This means that BC Hydro chose the majority view and built the final plan based on that view, but the area of non-consensus was documented and presented in the consultation report in full.

By order on February 17, 2006, the comptroller of water rights required BC Hydro to operate its works in accordance with the procedures that would implement the revised WUP. Although BC Hydro would still have to increase base flow in the Cheakamus River over their historical practice, there would be less water required than under the Interim Flow Agreement. This allowed BC Hydro to generate more electricity at their generating station on the Squamish River, resulting in additional power with an estimated value of $7 million annually.

The order required specific minimum releases from Daisy Lake dam into the Cheakamus River for fish habitat, and also specified additional releases as necessary to maintain specified flows for fish and recreational use, as measured at the Brackendale Water Survey of Canada gauge. The comptroller also ordered that 10 monitoring programs be developed in consultation with federal and provincial agencies. Monitoring reports have been received annually since 2008.

To date, the monitoring program shows that changes introduced by the WUP do not appear to have resulted in an increase or stabilization of the rainbow trout population parameters of relative condition, size-at-age, or abundance. A longer-term study is needed, including the collection of further evidence. A complicating factor was the Canadian National Railway derailment in 2005, which dumped 40,000 litres of caustic soda, killing fish and confounding the WUP monitoring and work benefits.

The Cheakamus WUP was originally scheduled for a five-year review, which should have happened in 2011. Instead, in 2011 BC Hydro met with the Cheakamus WUP Monitoring Advisory Committee, and they agreed that the monitoring studies should be continued for another five years.

Even with a non-consensus WUP, the process benefits may be seen. All stakeholders have a better understanding of the operation of the hydroelectric facility and of the interactions among the water releases, the ecosystem (particularly as it affects fish), and the other users of the water, including the rafting community. The monitoring is well designed and focused, and will help resolve areas of disagreement among the stakeholders. Adaptive management is included in the comptroller’s order, and changes in flows may be, and have been, authorized annually depending on the in-stream needs and water availability.

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