Columbia River Treaty Review Technical Studies

Author: B.C. Hydro, Power Authority

The purpose of this report is to evaluate how environmental and social values in BC may be affected by the potential strategic decision on the future of the Treaty. To accomplish this, the report focuses on exploring how environmental and social interests could be affected, both positively and negatively, in Treaty Terminate versus Treaty Continue scenarios. The technical analysis in this report was limited to Canadian interests that have the potential to be affected by operations at Columbia River Treaty dams (Mica, Arrow, Duncan and Libby). This limited the geographic study area to the reservoirs and downstream river (and lake) segments on the Kootenay and Columbia rivers to the US border. Okanagan salmon that migrate through the lower Columbia River in the US to the confluence with the Okanagan River and up into Canada are also of interest and are being assessed in a separate report. The Ministry of Energy, Mines and Natural Gas Columbia River Treaty Review team has overall responsibility for the Treaty Review process. Working with BC Hydro and a team of independent facilitators and consultants, their tasks include technical modelling and analyses, stakeholder engagement, First Nations consultation, and making the recommendations to provincial Cabinet.

Preliminary key findings for the Columbia system may be summarized as follows:

Operating constraints on Kinbasket reservoir have the highest costs (especially if firm energy is impacted), regardless of Treaty Termination (Improvements to recreation, navigation and potentially vegetation/wildlife and the operating cost and cost of building new sources of firm energy are similar whether the Treaty continues or is terminated.):

Treaty Continue: Due to the large generation capability at Mica and Revelstoke (5700 MW, ~50% of BC Hydros capacity), changes at Mica are the most costly and provide limited gains for interests around the reservoir.

Treaty Terminate: In Treaty Terminates, more radical changes to operations could be developed that could provide greater benefits to interests around the reservoir, but at an even higher cost. This domestic trade-off remains the same.

With Treaty Termination, Arrow Lakes operational choices become less linked to choices made at Kinbasket:

Treaty Continue: Under the Treaty Continue scenario, there will always be a need to balance between Kinbasket/Arrow as the border flow releases from Canadian storage are set by the Treaty operations. If Arrow is low, Kinbasket will be higher and vice versa.

Treaty Terminate: Under a Treaty Terminate scenario, Arrow reservoir levels can change without having the same impact on Kinbasket reservoir, thereby creating more opportunity to operate Arrow for other interests.

Regardless of the Treatys future, value trade-offs at Arrow will remain:

Treaty Continue: Alternative 3 demonstrates the trade-off at Arrow reservoir under a Treaty Continue scenario where significant benefits to vegetation, bird and wildlife values in the Mid-Columbia River can be gained by a lower reservoir elevation, however these result in the loss of power revenues and declines in kokanee tributary access and recreation days in Arrow Lakes Reservoir

Treaty Terminate: The de-linking of Kinbasket and Arrow reservoirs enables different operations at Arrow reservoir that could provide a different (and potentially better) balance between the high and low Arrow reservoir interests. However, as Figure 9 illustrates, several of the key interests in Arrow Lakes reservoir are mutually exclusive, and so tough trade-off choices will remain.

Treaty Terminate opens up new trade-off opportunities / constraints between Arrow and the Lower Columbia River:

Treaty Continue: Under the Treaty Continue scenario, BC Hydro is able to meet Lower Columbia River spawning flows in the January through June period, although this does result in high Arrow reservoir levels in the spring which impacts the Mid-Columbia interests that prefer lower levels in the spring but benefits reservoir based recreation.

Treaty Terminate: The potential for different operations creates quite different trade-offs between Arrow reservoir and the downstream river section that were not investigated in the water use plan.

Like the Columbia River system there are a number of trade-offs that are inherent in operations on the Kootenay system. Preliminary key findings may be summarized as follows:

Deeper Libby drafts provides benefits in Canada over the current regime for some interests while other interests perform better under the current regime.
The Libby Power and Standard Flood Control operating regime that existed prior to 1993 drafts Libby deeper than the current regime
Called Upon operations are expected to cause Koocanusa to draft deeper more often, possibly resulting in an operation somewhere between the current regime (Alt1) and the Standard Flood Control regime (Alt 2)

Benefits: Less flooding on Kootenay Lake, more power benefit, less spill, improvements for aquatic health in Kootenay River below Nelson, potential benefit to vegetation and wildlife on Koocanusa Reservoir.

Impacts: May have negative impacts on aquatic productivity and recreation on Koocanusa reservoir

There is potential that current operations could be altered to benefit a wider range of interests in Canada through an operation such as that illustrated in Alternative 3b.
Alternatives that do not meet the U.S. fisheries requirements that are court ordered under the Biological Opinion are unlikely to be implemented

Benefits:May benefit Koocanusa resident fish and recreation, flood reduction at Kootenay Lake, reduced spill in the Kootenay River which produces environmental benefits and power benefits

Impacts: May increase the risk of surcharging Koocanusa Reservoir
Does not meet the current U.S. fisheries requirements