Arrowrock Hydroelectric Project
Elmore County, Idaho · EIA plant ID 56997 · Operator: Boise-Kuna Irrigation District
Nameplate15MWSummer 16 MW
Generators2in service
Net generation63GWh12 mo to Dec 2025
Capacity factor45%hydro units, summer MW
Heat rate—thermal plants only
First online2010
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
Capacity factor by year
Net MWh ÷ (summer MW × hours), hydro units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Heat rate applies to fuel-burning (thermal) units only.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2010 | 77.6 | 73.5% | — |
| 2011 | 84.9 | 60.6% | — |
| 2012 | 75.9 | 54.0% | — |
| 2013 | 48.9 | 34.9% | — |
| 2014 | 72.7 | 51.8% | — |
| 2015 | 65.4 | 46.7% | — |
| 2016 | 66.8 | 47.5% | — |
| 2017 | 80.9 | 57.7% | — |
| 2018 | 77.3 | 55.1% | — |
| 2019 | 59.7 | 42.6% | — |
| 2020 | 67.3 | 47.9% | — |
| 2021 | 38.2 | 27.3% | — |
| 2022 | 53.4 | 38.1% | — |
| 2023 | 55.9 | 39.9% | — |
| 2024 | 73 | 52.0% | — |
| 2025 | 63.2 | 45.1% | — |
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | HY | 7.5 | 8 | Apr 2010 | Operating | — | coming soon |
| 2 | Conventional Hydroelectric | HY | 7.5 | 8 | Apr 2010 | Operating | — | coming soon |
Owner / operator
Operator: Boise-Kuna Irrigation District. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Boise-Kuna Irrigation District | 100.0% | 15 MW |
Nearby plants
Within 80 km.
| Lucky Peak Power Plant Project | 101 MW | 13.2 km |
| Boise R Diversion | 3 MW | 15.1 km |
| Barber Dam | 4 MW | 16.4 km |
| Boise Bench BESS | 150 MW | 19.1 km |
| Blacks Creek Solar | — | 24.1 km |
| Pleasant Valley Solar 2 Project | 125 MW | 30.2 km |