Headgate Rock — United States of America

Headgate Rock is a 19.5 MW hydro power plant in Arizona, United States of America. It is operated by Colorado River Indian Irr Proj. Based on reported annual generation of 72 GWh, it can supply roughly 21k homes. It ranks #4850 of 10,884 United States of America power plants by installed capacity. Commissioned in 1993, it is around 33 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 5.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0007179.

Data provenance

Source of the capacity and fuel values:

capacity: Wikidata P2109; fuel: WRI GPPD

In context: how this plant compares

At 19.5 MW, Headgate Rock is well above the median hydro plant in United States of America (8 MW). Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Key facts

Load factor

42%, from 72 GWh of reported generation, in line with the 42% median for 1342 hydro plants in United States of America

Generation trend

79 GWh in 2013 and 72 GWh in 2019 (−8%)

Highest and lowest year

2014: 80 GWh; 2018: 68 GWh

Share of United States of America hydro capacity

less than 0.1% of 102,513 MW across 1,449 plants in this dataset

Age among peers

1,306 of 1,444 dated hydro plants in United States of America are older

Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).

Reported generation trend

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Colorado River Indian Irr Proj.

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a hot desert climate (Köppen BWh) — Northern Hemisphere, latitude 34.2°N — which shapes how much energy it can produce and how its output varies through the year.

Monthly mean temperature

Heating degree-days here run 77% below the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.

Climate heat-demand index: 21/100 — this site sits in the bottom third of the power plants we cover by heating degree-days.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

Site climate & environmental severity

This site sits in a benign, low-corrosion environment (estimated ISO 9223 class C1 — Very low), with dust abrasion the leading environmental stress.

Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.

How it compares & nearby plants

The #481 largest hydro power plant of 1449 in United States of America by capacity.

United States of America has 1449 hydro power plants in this dataset, together about 102,513 MW of capacity.

Nearby power plants

• Parker Dam · Hydro · 120 MW · Arizona
• Vidal nuclear power plant · Nuclear · 1,540 MW · California
• Palo Verde College · Solar · 1.2 MW · California
• McCoy Solar Energy Project Hybrid · Solar · 270 MW · California
• Blythe Solar II LLC · Solar · 131.2 MW · California
• Venable Solar 1 · Solar · 1.5 MW · California

Location

Coordinates 34.1683, -114.2774 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions