Stewart Mountain — Plant Summary
- EIA Plant ID
- 150
- Capacity
- 13 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- Maricopa, AZ
- Operating Since
- 1930
- Generators
- 1
- Operator
- Salt River Project
- Parent Company
- Salt River Project
- Annual Generation
- 45,765 MWh
- Capacity Factor
- 40.0%
- Balancing Authority
- Salt River Project
- ISO/RTO
- —
- NERC Region
- WECC
Stewart Mountain
OperatingHydro
Ranked #9 of 11 Hydro plants in AZ#575 of 1454 nationally
13 MW Hydro operating in Maricopa, AZ — Salt River Project
EIAWD
13 MW
Nameplate Capacity
1
Generators
unit
Conventional Hydroelectric
Technology
1930
Operating Since
Location
Coordinates
33.5661, -111.5360
County
Maricopa, AZ
Nearby Plants
- Mormon FlatHydro63.5 MW · 8.7 km
- Horse MesaHydro131.3 MW · 18.0 km
- Pediment BESS IBESS250 MW · 24.2 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Salt River Project | Salt River Project | — |
| Owner(s) | Salt River Project | Salt River Project | — |
| Status | Operating | — | — |
Ownership Chain
About
The Stewart Mountain Dam is a concrete thin arch dam located 41 miles northeast of Phoenix, Arizona. The dam is 1,260 feet (380 m) long, 207 feet (63 m) high, and was built between 1928 and 1930. The dam includes a 13,000 kilowatt (kW) hydroelectric generating unit that is operated by SRP, an Arizona public utility. It is primarily operated during the summer months. The dam forms Saguaro Lake as it slows the passage of the Salt River in Maricopa County, Arizona. It was named after a ranch that used to be located nearby known as the Old Stewart Ranch.
Read more on WikipediaStewart Mountain is a 13 MW hydroelectric power plant located in Maricopa County, Arizona. The plant, which began operating in 1930, utilizes conventional hydroelectric technology and is owned and operated by the Salt River Project (SRP). It has one generator and uses water (WAT) as its primary fuel source. The plant's balancing authority is also the Salt River Project.
In the most recent year with available data, Stewart Mountain generated 45,765 MWh of electricity, achieving a capacity factor of 40.0%. Within Arizona, the plant ranks 9th out of 11 hydroelectric facilities. Nationally, it is ranked 591 out of 1464 similar plants. The plant operates within the Western Electricity Coordinating Council (WECC) NERC region.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
Salt River Project
Grid Voltage
115 kV
Regulatory Status
RE
Entity Type
Political Subdivision
Sector
Electric Utility
Generation
0 MWh
Latest Month
45.8K MWh
Annual Generation
40.0%
Capacity Factor
Jan 2022 – Dec 2024
Financial Data
No financial data available for this plant.
Pricing & Market Data
This plant is outside organized wholesale electricity markets (ISOs/RTOs). Nodal pricing data is not available.
News & Articles (10)Beta
Industry·technology
Salt River Project completes hydropower modernisation, improves efficiency and reliability
Salt River Project (SRP) has completed a multi-year upgrade of its hydroelectric facilities along the Salt River in Arizona.
Salt River Project (operator)
International Water Power·5 months ago
Industry·technology
Salt River Project completes hydropower modernisation project
Emerson, an industrial technology leader delivering advanced automation solutions, has completed a multi-year modernisation project at four...
Emerson (other)Salt River Project (other)
Energy Global·5 months ago
Industry·technology
Salt River Project, Emerson Complete Hydropower Modernization Project
Industrial technology group Emerson said the company has completed a multi-year modernization project at four hydroelectric dams along the...
Salt River Project (operator)Emerson (other)
POWER Magazine·5 months ago
Industry·technology
Salt River Project completes modernization project for three hydroelectric dams
Emerson completed the modernization of excitation systems at four hydroelectric dams operated by Salt River Project in Arizona.
Salt River Project (operator)Emerson (other)
Power Engineering·5 months ago
Last updated 2026-03-14
View all 10 articles