Arrowrock Hydroelectric Project
Hydro power plant · Elmore County, Idaho
Nameplate capacity
15 MW
Rank in Idaho
#75
of 155 plants
In service since
2010
April 2010
Details
- Primary fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Operator
- Boise-Kuna Irrigation District
- County
- Elmore County
- Generating units
- 2
- Share of state capacity
- 0.23%
- Rank among hydro plants in Idaho
- #22 of 76
- EIA plant code
- 56997
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | 7.5 MW | 8.0 MW | 2010 | Operating |
| 2 | Conventional Hydroelectric | 7.5 MW | 8.0 MW | 2010 | Operating |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in Idaho
| Raft River Geothermal Power Plant | Other | 16 MW |
| Simplot Leasing Don Plant | Other | 16 MW |
| Shoshone Falls | Hydro | 15 MW |
| Soda | Hydro | 15 MW |
About this data
From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 15 MW solar plant and a 15 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Idaho power plants · What Idaho actually generates