131.3 MW Conventional Hydroelectric (32 MW) + Hydroelectric Pumped Storage (100 MW) operating in Maricopa, AZ — Salt River Project
131.3 MW
Nameplate Capacity
4
Generators
units
Hybrid (2)
Technology
Conventional Hydroelectric + Hydroelectric Pumped Storage
1927
Operating Since
Coordinates
33.5907, -111.3440
County
Maricopa, AZ
Nearby Plants
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Salt River Project | US Bureau of Reclamation [100%] | — |
| Owner(s) | Salt River Project | Salt River Project | — |
| Status | Operating | operating | — |
The Horse Mesa Dam is a concrete thin arch dam located in the Superstition Mountains, northeast of Phoenix in Maricopa County, Arizona.
Read more on WikipediaHorse Mesa is a 131.3 MW hydroelectric power plant located in Maricopa County, Arizona. The plant, which began operating in 1927, is owned and operated by Salt River Project. It utilizes conventional hydroelectric and pumped storage technologies, and is considered a hybrid plant. The facility has four generators and its primary fuel source is water (WAT).
In the most recent year of reported data, Horse Mesa generated 87,872 MWh of electricity, achieving a capacity factor of 7.6%. The plant operates within the Salt River Project balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. Horse Mesa is ranked as the 4th largest hydroelectric plant out of 4 in Arizona, and 147th out of 194 nationally.
Generated from EIA, GEM, and public data sources
NERC Region
WECC
Balancing Authority
Salt River Project
Grid Voltage
115 kV
Regulatory Status
RE
Entity Type
Political Subdivision
Sector
Electric Utility
242 MWh
Net Discharge
87.9K MWh
Annual Net Energy
7.6%
Capacity Factor
Positive values indicate net discharge (generation exceeds station load). Negative values indicate net charging. Pure battery storage plants are typically net negative due to round-trip efficiency losses.
No financial data available for this plant.
This plant is outside organized wholesale electricity markets (ISOs/RTOs). Nodal pricing data is not available.
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Last updated 2026-03-14
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