Columbia River Treaty 2014/2024 Review

Author: Canadian , United States Entities

This Phase 1 report of the 2014/2024 Columbia River Treaty Review describes the results of the three Phase 1 studies. The purpose of the Phase 1 studies was to provide information about post-2024 conditions both with and without the current Treaty from the perspective of the two purposes of the Treaty, power and flood control.

The Phase 1 technical studies provided a broad range of information and data that required considerable assessment and evaluation. The outcomes were a result of not only the scenarios selected, but also the assumptions and the modeling methodologies employed. As a result, considerable review was required to understand these outcomes and results. This section is meant to summarize and focus on the key outcomes and conclusions from the Phase 1 studies.

4.1.CALLED UPON FLOOD CONTROL
– Regardless of whether the Columbia River Treaty continued after 2024, changes in flood control operations from the FCOP to Called Upon had significant effects on the operations of both U. S. and Canadian storage reservoirs.
– The frequency that Called Upon operations was required was driven by the procedure and maximum flood control objective at the Dalles, Oregon. Based on the assumed procedure and objectives used in these studies, Called Upon storage in Canadian reservoirs was needed 21 years (30%) out of 70 years for every scenario when the maximum flow objective at The Dalles was 600 kcfs, and 52 years (74%) when 450 kcfs was the maximum flow objective. The joint study team believes those results overestimated the frequency of Called Upon years. Refinement of models, assumptions, and evaluation criteria is recommended to better estimate the frequency and duration of Called Upon storage needs (see section 5). Although flow objectives of 600 kcfs and 450 kcfs were used in the studies, there are differences between the Entities with regard to interpretation of Called Upon rights and obligations, including flood control objectives.
– The volume of Canadian storage requested by the U.S. for Called Upon was significantly less under the Treaty Continues studies (approximately 1-1.5 Maf on average) compared to Treaty is Terminated. Under Treaty is Terminated, the (power or flood control) draft at Canadian projects had a major impact on the additional draft needed for U.S. flood control, and there was a wide range (generally 5-11 Maf) in the volume of storage that was required for Called Upon.
– Canadian Treaty storage was very effective in controlling flood events in the United States. In the Phase 1 studies, peak flow at The Dalles was the best measure of flood control effectiveness of the scenarios investigated. Peak flows varied little across all the scenarios in Called Upon years. However, this study outcome was due largely to the modeling methodology used in the studies. When Called Upon operation was triggered, Canadian and U.S. reservoirs were all drafted to the same volume regardless of maximum flow objective, and the regulation in the spring was similar. While this approach was effective in controlling flooding in the U.S., it may not represent the most efficient use of water and storage across multiple operating purposes. Other strategies and procedures for implementing Called Upon operations need to be investigated (see section 5).
– Most of the Called Upon draft was required from Arrow reservoir since it is the most effective Canadian reservoir for managing reductions in flows at The Dalles. Because of the deep power draft at Mica, Called Upon did not usually affect Mica, and similarly, had only a minor impact at Duncan.
– A cursory evaluation of the impacts of Called Upon and Flex operations on each other showed that it was physically possible to transition from a Flex operation to a Called Upon operation. However, having Mica on minimum flow (and therefore low generation amounts) for up to three months in winter in order to transition to a Called Upon operation poses a high risk to BC Hydro power reliability and may impact non-power requirements. The impact of Flex on Called Upon needs to be investigated further (see section 5).

4.2.POWER LOADS AND RESOURCES
– The projected loads used in all the Phase 1 studies showed an increase of 3,477 MW between 2013-14 and 2024-25 and an 8,420 MW increase from 2024-25 to 2044-45.
– To meet this load increase in the Phase 1 studies, resources were added during each forecast period. From 2014-15 to 2024-25, the majority of the load increase was met by renewables, primarily wind generation (2,563 MW). During the period 2025-26 through 2044-45, the majority was met through thermal generation (6,932 MW), with the remainder generally being met by wind (1,050 MW).
– The seasonal shape (month to month) of firm loads, imports/exports, and thermal resources is very important yet highly uncertain. The net result of these loads and resources is the Residual Hydro Load, which has a direct effect on the Canadian storage operation and the Canadian Entitlement.

See full section “Summary and Key Findings” (pp. 75-79).

The Phase 1 technical studies provided a broad range of information and data that required considerable assessment and evaluation. The outcomes were a result of not only the scenarios selected, but also the assumptions and the modeling methodologies employed. As a result, considerable review was required to understand these outcomes and results. This section is meant to summarize and focus on the key outcomes and conclusions from the Phase 1 studies.

4.1.CALLED UPON FLOOD CONTROL
– Regardless of whether the Columbia River Treaty continued after 2024, changes in flood control operations from the FCOP to Called Upon had significant effects on the operations of both U. S. and Canadian storage reservoirs.
– The frequency that Called Upon operations was required was driven by the procedure and maximum flood control objective at the Dalles, Oregon. Based on the assumed procedure and objectives used in these studies, Called Upon storage in Canadian reservoirs was needed 21 years (30%) out of 70 years for every scenario when the maximum flow objective at The Dalles was 600 kcfs, and 52 years (74%) when 450 kcfs was the maximum flow objective. The joint study team believes those results overestimated the frequency of Called Upon years. Refinement of models, assumptions, and evaluation criteria is recommended to better estimate the frequency and duration of Called Upon storage needs (see section 5). Although flow objectives of 600 kcfs and 450 kcfs were used in the studies, there are differences between the Entities with regard to interpretation of Called Upon rights and obligations, including flood control objectives.
– The volume of Canadian storage requested by the U.S. for Called Upon was significantly less under the Treaty Continues studies (approximately 1-1.5 Maf on average) compared to Treaty is Terminated. Under Treaty is Terminated, the (power or flood control) draft at Canadian projects had a major impact on the additional draft needed for U.S. flood control, and there was a wide range (generally 5-11 Maf) in the volume of storage that was required for Called Upon.
– Canadian Treaty storage was very effective in controlling flood events in the United States. In the Phase 1 studies, peak flow at The Dalles was the best measure of flood control effectiveness of the scenarios investigated. Peak flows varied little across all the scenarios in Called Upon years. However, this study outcome was due largely to the modeling methodology used in the studies. When Called Upon operation was triggered, Canadian and U.S. reservoirs were all drafted to the same volume regardless of maximum flow objective, and the regulation in the spring was similar. While this approach was effective in controlling flooding in the U.S., it may not represent the most efficient use of water and storage across multiple operating purposes. Other strategies and procedures for implementing Called Upon operations need to be investigated (see section 5).
– Most of the Called Upon draft was required from Arrow reservoir since it is the most effective Canadian reservoir for managing reductions in flows at The Dalles. Because of the deep power draft at Mica, Called Upon did not usually affect Mica, and similarly, had only a minor impact at Duncan.
– A cursory evaluation of the impacts of Called Upon and Flex operations on each other showed that it was physically possible to transition from a Flex operation to a Called Upon operation. However, having Mica on minimum flow (and therefore low generation amounts) for up to three months in winter in order to transition to a Called Upon operation poses a high risk to BC Hydro power reliability and may impact non-power requirements. The impact of Flex on Called Upon needs to be investigated further (see section 5).

4.2.POWER LOADS AND RESOURCES
– The projected loads used in all the Phase 1 studies showed an increase of 3,477 MW between 2013-14 and 2024-25 and an 8,420 MW increase from 2024-25 to 2044-45.
– To meet this load increase in the Phase 1 studies, resources were added during each forecast period. From 2014-15 to 2024-25, the majority of the load increase was met by renewables, primarily wind generation (2,563 MW). During the period 2025-26 through 2044-45, the majority was met through thermal generation (6,932 MW), with the remainder generally being met by wind (1,050 MW).
– The seasonal shape (month to month) of firm loads, imports/exports, and thermal resources is very important yet highly uncertain. The net result of these loads and resources is the Residual Hydro Load, which has a direct effect on the Canadian storage operation and the Canadian Entitlement.

See full section “Summary and Key Findings” (pp. 75-79).