Council staff to analyze power system impacts of different hydrosystem operations

Over the next two months, Council Power Division staff will be analyzing a set of hydro operations for the upcoming processes of amending the Columbia Basin Fish and Wildlife Program and preparing to develop the cost-effective resource strategy for the Ninth Power Plan.

These operations primarily focus on federal projects in the lower Columbia River, from Bonneville to McNary dams, and the four lower Snake River projects. At the Council’s August meeting in Portland, Power Planning Director Jennifer Light, General Counsel John Shurts, Power System Analyst Dor Hirsh Bar Gai, and Fish and Wildlife Program Scientist Kate Self led a presentation about a proposed scope for this analysis (read presentation | watch video).

Council members agreed to proceed with this scope, and staff will be working in August and September to produce this analysis. Their goal is to present results to the Council at its October meeting.

Light emphasized that this analysis will be helpful in information-gathering as the Council evaluates recommendations in its ongoing process of amending the Fish and Wildlife Program, and eventually in recommending new resources in the Ninth Power Plan. The Council aims to adopt a new Fish and Wildlife Program and the Ninth Plan in 2026.

The upcoming analysis will not lock the Council into including any specific recommendations in the Fish and Wildlife Program. Power system implications are one factor of many that the Council will consider in amending the Program. Nor does it provide all the information needed to make decisions in the Ninth Plan.

Staff’s analysis will focus on four key areas:

• Assumed operations for 2026 based on the 2020 BiOp
• Another sensitivity with a steady spill approach
• Hydrosystem flexibility
• Minimum operating pool and spill

2026 operations

Approximating operations for 2026 is useful to provide information on power system needs based on today’s operations, as well as a point from which to understand the implications of changes contained in the flexibility and minimum operating pool sensitivities.

For 2024 and 2025, hydrosystem operations include fish mitigation operations defined in Biological Opinions, as well as the 2023 Resilient Columbia Basin Agreement (RCBA) between the U.S. government, four basin tribes, and the states of Washington and Oregon. Operators are also accounting for the current Columbia River Treaty operations based on the Agreement in Principle, and requirements for flood control, recreation, and transportation, among other uses.

In June, President Donald Trump announced he was withdrawing the federal government from the RCBA agreement. That has created subsequent uncertainty on what hydrosystem operations will revert to in 2026 and beyond. This uncertainty is likely to linger into upcoming months.

Light said staff has been discussing the issue with the Bonneville Power Administration and other federal partners in the Northwest. Given the uncertainty, staff has proposed to model operations based on the 2020 CRSO EIS preferred alternative to represent a “current operations” sensitivity in the power plan. Legally, until another agreement is in place, the system should revert to these operations defined in the Biological Opinions.

In addition, staff propose a sensitivity which will model the 2023 RCBA. While these operations have been revoked, they provide a concrete set of operations that represent a more “steady spill” approach. Adding this sensitivity will provide sufficient information to inform power system needs recognizing the uncertainty of 2026 operations.

Hydro flexibility

Staff plan to analyze the power system implications of limiting the hydrosystem’s ability to change daily elevations and outflows. The Council’s 2014 Fish and Wildlife Program contained measures recommended by the state and tribal fish and wildlife managers calling on system operations to minimize or reduce daily flow fluctuations.

The Council’s redeveloped GENESYS model show the ability for the system to increase daily fluctuations, while still meeting seasonal operational constraints. With this insight, the 2021 Power Plan noted that these fluctuations may be one route for ensuring system adequacy, because the flexibility in hydropower increases the electricity system’s ability to respond to economic and power considerations, including reserves, and support the integration of renewables as loads increase. The 2021 Power Plan called on the Council and the region to investigate the implications of these changing river flows, exploring the possible benefits and consequences of different hydropower system operations to identify a path forward that provides greater benefit to both power and fish.

This year, the Council has received recommendations to amend the Fish and Wildlife Program to minimize within-day flow fluctuation, eliminate zero-flow operations, and develop minimum flow requirements. Increased daily flow fluctuations can negatively affect prey availability, fish migration times, egg desiccation, stranding juveniles, and predation susceptibility, among other impacts. Staff developed an approach to analyze a reduction in daily flexibility throughout the year.

Minimum operating pool

The analysis for minimum operating pool and spill come from recommendations the Council received in 2025. Multiple entities submitted recommendations to the Council on this issue, including some states and tribes. Staff will analyze the specific recommended operations around minimum operating pool (MOP) elevations and related limits, as well as the recommended spill operations. This will provide insight on the power system implications of these potential operations.