LIHI Certificate #53 - Bear River Project, Idaho

March 25, 2020 -COVID-19 Update: Pacificorp has issued this press release  announcing closures of most of their recreation areas.  Information on the status of their recreation facilities are available at https://www.pacificorp.com/community/recreation.html

The Bear River Project is located on the Bear River in Caribou and Franklin Counties, Idaho. The Bear River Basin is located in northeastern Utah, southeastern Idaho, and southwestern Wyoming. The river itself begins in the Uinta Mountains in Utah and extends 500 miles, crossing state boundaries five times before ending in the Great Salt Lake. Completely enclosed by mountains, it is the largest tributary to Great Salt Lake as well as the largest stream in the western hemisphere that does not empty into an ocean. The Bear River project consists of three dams and powerhouses – Soda, Grace, and Oneida developments. The Soda development is located the farthest upstream on the Bear River, five miles west of the city of Soda Springs in Caribou County, Idaho. The Last Chance (also owned by PacifiCorp) development is located on the Last Chance Canal, a diversion from the Bear River that is located four miles downstream of the Soda powerhouse. The Grace development is the next facility downstream, and it is also located in Caribou County, Idaho. The Oneida Project is located in Franklin County, Idaho, approximately 6 miles south of Cleveland, Idaho.

The project includes three developments:

  • Soda: The Soda development consists of a 103-foot-high by 433-foot-long concrete gravity dam with a 109-foot-long integral powerhouse section containing five headgates that supply water to the generating unit penstocks and to a 900 cfs-capacity low-level discharge (Johnson valve). The dam also has a 210-foot-long non-overflow gravity section and a 114-foot-long gated overflow spillway section containing three, 30-foot by 14-foot Tainter gates. A 55-foot-long by 19-foot-high earth fill dam also forms parts of the development. The Soda reservoir (commonly referred to as the Alexander reservoir) has a surface area of 1,100 acres. It extends approximately 4.5 miles upstream to just below the Big Spring Creek confluence with the Bear River. The powerhouse contains two vertical Francis units, each with an installed capacity of 7 MW.
  • Oneida: The Oneida development includes a 111-foot-high by 381-foot-long concrete gravity dam that includes a 118-foot-long uncontrolled auxiliary spillway, a 66-foot-long non-overflow gravity section, a 99-foot-long gated spillway containing five Tainter gates, and an 86-foot-long gravity section with ice sluices. There is also a 40-foot-high, 1,100-foot-long embankment dam. The Oneida reservoir has a surface area of 480 acres. A 50-foot-wide by 50-foot-high intake structure, containing six openings fitted with trashracks, transitions to two, 16-foot-diameter circular outlets. A 16-foot-diameter, 2,240-foot-long steel flowline conveys water from the intake structure to a 40-foot-diameter, 142-foot-high surge tank. Three 12-foot-diameter, 120-foot-long steel penstocks extend from the surge tank to the powerhouse which contains three vertical Francis units, each with an installed capacity of 10 MW. The development has a 64-foot-wide by 118-feet-long rectangular channel tailrace.
Project Name Bear River
LIHI Certificate No. 53
LIHI Certificate Term December 31, 2014 - December 31, 2022
Owner PacifiCorp Energy
State Idaho
Location Located between river mile 143 and 183 on the Bear River in northeastern Utah, southeastern Idaho, and southwestern Wyoming.
Installed Capacity Total: 77 MW Soda Development: 14 MW Grace Development: 33 MW Oneida Development: 30 MW
Average Annual Generation Total: 199,840 MWh (based on past 30 years) Soda Development: 25,070  MWh Grace Development: 122,110 MWh Oneida Development: 52,660  MWh
Facility Type Modified run-of-river
FERC No. P-20 issued 2003, expires 2033
  • Grace: The original Grace dam and the existing power facilities were constructed shortly after 1910. A new dam was constructed in 1951 and the original rock-filled, timber-crib dam is now submerged in the forebay just upstream of the 1951 dam. Grace fam is a rock-filled, timber-crib structure with a concrete core at the base of the structure. The structure stands approximately 51 feet high with 8-foot-high flashboards. The crest length is 180.5 feet. The dam creates a 320 acre-feet impoundment. A 52-foot-wide intake structure containing eighteen 5-foot by 10-foot screen sections is housed within a concrete stucco building, adjacent to the earth embankment section of the dam. A 26,000-foot-long 11-foot-diameter flowline consisting of 15,000 feet of steel and 11,000 feet of wood stave pipeline conveys water from the intake structure to two surge tanks, one 10 feet in diameter and 38 feet high, located approximately 2.6 miles downstream of the diversion, and the other 30 feet in diameter and 132 feet high, located directly above the powerhouse. Three 90-inch-diameter steel penstocks equipped with two butterfly valves carry water from the surge tanks to the powerhouse. The powerhouse has three turbine generators rated at 11 MW each for a total plant capacity of 33 MW. The tailrace includes a short concrete-lined section that transitions to an unlined open channel section approximately 350 feet from its confluence with the Bear River.

The project operates in coordinated modified run-of-river mode to meet irrigation demands in addition to generating power. River flows are generally higher than the natural conditions during the irrigation season (April through October) due to irrigation releases from Bear Lake. The Soda, Grace, and Oneida developments are usually operated in a modified run-of-river mode during this season; water stored in Soda and Oneida reservoirs may be used to satisfy short-term irrigation demand. Each development provides minimum flows:

  • Below the Soda dam - year-round minimum flow of 150 cfs, or inflow into the Alexander reservoir, whichever is less;
  • Grace bypass reach - year-round minimum bypass flow of 63 cfs or inflow, whichever is less, in addition to 2 cfs leakage from the dam;
  • Oneida reach below the powerhouse: year-round minimum flow of 250 cfs or inflow, whichever is less, in addition to 1 cfs leakage from the dam.

Waters within the project reach are used for irrigation and power generation. Water quality monitoring has occurred several times at the developments to determine the project's impacts on temperature, dissolved oxygen, nutrients, and turbidity. The primary concern with water quality at the project is excess sediment which was mitigated via the elimination of peaking events and the establishment of a maximum ramping rate. The Idaho Department of Environmental Quality has noted that the project is not contributing to exceedances of water quality standards.

No anadromous fish species have been noted in the project area. Additionally, there are limited numbers of native fish in Bear River, thus fish entrainment has not been a significant issue at the project. Bear River has been targeted for restoration, enhancement, and protection activities for riverine fisheries with a particular focus on the Bonneville cutthroat trout. A Restoration Study Plan was implemented to establish baseline habitat conditions and fish passage obstruction and diversion information in order to better conserve this species.

The project lands consist of 42 acres. The project operates under a Habitat Restoration Program, contributes to a Land and Water Conservation Fund, funds a broodstock and conservation hatchery program with Idaho Department of Fish and Game, and contributes to creel and macroinvertebrate studies. Project contributions to these programs and funds totaled $648,000 originally with annual funding of up to $567,000 to support watershed protection, as approved under the relicensing Settlement Agreement. These programs have established conservation lands, helped to enhance Bonneville cutthroat trout populations, assessed recreation impacts on the river, and more.

PLUS-Standard: The project owner provides annual funding of over $500,000 to support habitat conservation measures in areas impacted by the project. Dedicated buffer zones have also been established around the project areas. Collectively, approximately 1,637 acres have been designated conservation lands.

Threatened or endangered species potentially present in the project vicinity include the bald eagle, Canada lynx, Ute’s ladies’ tresses, Kelsey’s phlox, and red glasswort. Consultation with the US Fish and Wildlife Service concluded that project operations are not likely to adversely impact any of the listed species.

The three developments each support several historic or archaeological sites. In total, the project has over 60 sites of historic or archaeological significance, thus a Historic Properties Management Plan was developed to protect and manage these properties. Annual reports of activities concerning these sites are filed with the State Historic Preservation Office, the US Bureau of Land Management, and the Shoshone-Bannock Tribes. Project operational staff receive cultural resources training to ensure proper stewardship of the properties.

Recreational resources at the project include two campgrounds managed by the Bureau of Land Management, put-in/take-out access points in the Grace bypass and Oneida downstream reach, and whitewater releases conducted in consultation with American Whitewater. Additionally, the project provides funding to the Bureau of Land Management and Caribou and Franklin County for management of the recreational sites in the project vicinity. Public access is provided free of charge to the reservoirs and downstream reaches of the projects.


Certification History

July 24, 2015: LIHI Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has determined that the Bear River Hydroelectric Project (FERC No. 20) continues to meet the LIHI Certification Criteria. The effective certification date for the Bear River Project is December 31, 2014 for an eight (8) year term, which will expire on December 31, 2022. The additional three years are earned for enhancements to the watershed.

February 3, 2015: The Low Impact Hydropower Institute received a complete and timely application for a new term of Low Impact Certification for the Bear River Hydroelectric project on November 20, 2014.  Please see the application files below.

May 19, 2010: The Bear River Hydroelectric Project has been certified as low impact for a five year term, effective December 31, 2009 and expiring December 31, 2014.

March 3, 2010: The public comment period has been closed.

December 31, 2009: PacifiCorp Energy has submitted an application for certification of the Bear River Hydroelectric Project. A public comment period will remain open for 60 days.