Federal Energy Regulatory Commission Approves Updated Whitewater Flow Plan

The Federal Energy Regulatory Commission (FERC) has issued a delegated order, approving the updated whitewater flow plan submitted by Northwestern Corporation for the Mystic Lake Hydroelectric Project. The updated plan aims to simplify and standardize the process for whitewater flow enhancements, provide more opportunities for recreationists to plan for release days, and simplify powerhouse operations for the licensee's staff.

Key Takeaways:

• The updated flow plan would introduce a fixed-date flow release schedule, with three to four whitewater flow enhancements per year, and provide sufficient notice for recreationalists to plan a visit to West Rosebud Creek.
• The licensee proposes to release 500 cubic feet per second (cfs) for 5 hours from West Rosebud Lake Dam, measured at the USGS Streamflow Gage No. 06204070 West Rosebud Creek (USGS Gage) at Emerald Lake Campground.
• The updated flow plan would continue to facilitate an annual coordination meeting with the Resource Group to discuss previous year's whitewater program results, snowpack, West Rosebud Creek runoff forecast, and Mystic Lake refill rate.
• The licensee consulted with the Resource Group, received concurrence from necessary stakeholders, and approval from the Forest Service, confirming the acceptability of the updated flow plan.
• The updated whitewater flow plan would be implemented for the next 10 years, through the 2034 recreation season, after which the licensee proposes to evaluate the effectiveness of the plan and provide a report to the Resource Group and the Commission by January 31, 2035.

Statistics:

• The updated flow plan proposes to release 500 cfs for 5 hours from West Rosebud Lake Dam.
• The fixed-date flow release schedule would provide three to four whitewater flow enhancements per year.
• The licensee proposes to evaluate the effectiveness of the updated flow plan, and file a report with the Commission at the conclusion of the 2025-2034 implementation period.
• The updated whitewater flow plan would be filed with the Commission every 10 years, starting from January 31, 2035.

Sources:

• United States of America, Federal Energy Regulatory Commission, Northwestern Corporation Project No. 2301-049, ORDER MODIFYING AND APPROVING WHITEWATER FLOW PLAN UPDATE (Issued May 14, 2025)