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San Dimas Wash Generating Station

Hydro power plant in California, United States of America. Approximate location 34.1242, -117.8051.

HydroCaliforniaUnited States of America

San Dimas Wash Generating Station is a 1 MW hydro power plant in California, United States of America. It is operated by San Gabriel Valley Mun Wtr Dt. Based on reported annual generation of 3 GWh, it can supply roughly 857 homes. It ranks #10789 of 10,938 United States of America power plants by installed capacity. Commissioned in 1986, it is around 40 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).

1Source-backed capacity
3GWh reported / yr
857homes powered
1986commissioned (~40 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0050233.

Data status

Known data

FacilitySan Dimas Wash Generating Station WRI
CountryUnited States of America · California WRI
Coordinates34.1242, -117.8051 WRI
FuelHydro WRI
MW installed capacity1 MW WRI source record; scope not independently normalised
OwnerSan Gabriel Valley Mun Wtr Dt WRI
Commissioned1986 WRI
GWh reported / yr3 GWh/yr WRI

Calculated from dataset

Capacity rank in country#10789 of 10938 calculated
Fuel-specific rank in country#1436 of 1449 calculated
Capacity vs country/fuel peers0.12× · 8 MW median · 1449 peers calculated
Homes-powered equivalent857 calculated from reported generation
Climate17.6°C · HDD 806 derived from coordinates
Environmental severityC5 · 47/100 derived from coordinates

Not available

TechnologyNot available not in dataset
GWh reported / yrNot available not in dataset
CO₂ emissionsnot applicable not applicable

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Data provenance

The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.

capacity: Wikidata P2109 nameplate capacity; fuel: WRI source-record fuel

In context: how this plant compares

At 1 MW, San Dimas Wash Generating Station is below 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.

Reported generation trend

2013: 0 GWh20132014: 0 GWh20142015: 0 GWh20152016: 2 GWh20162017: 0 GWh20172018: 1 GWh20182019: 3 GWh20193 GWh

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

Owner

Operated by San Gabriel Valley Mun Wtr Dt.

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a warm-summer Mediterranean climate (Köppen Csb) — Northern Hemisphere, latitude 34.1°N — which shapes how much energy it can produce and how its output varies through the year.

17.6°Cannual mean temp
806heating degree-days (base 18°C)
662cooling degree-days (base 18°C)
363 melevation

Monthly mean temperature

J: 12 °CJF: 13 °CFM: 14 °CMA: 16 °CAM: 18 °CMJ: 21 °CJJ: 24 °CJA: 24 °CAS: 23 °CSO: 19 °CON: 15 °CND: 12 °CD24 °C

Heating degree-days here run 67% 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: 24/100 — 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

For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in an aggressive, high-corrosion environment (estimated ISO 9223 class C5 — Very high), with marine salt corrosion the leading environmental stress.

C5ISO 9223 corrosivity (indicative)
47/100environmental-severity index
12.5°Cseasonal temperature swing
5 kmdistance to coast

Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.

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 #1436 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

Location

Coordinates 34.1242, -117.8051 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is San Dimas Wash Generating Station?

San Dimas Wash Generating Station is a 1 MW source-record hydro power plant in California, United States of America, commissioned in 1986.

How much electricity does San Dimas Wash Generating Station generate?

San Dimas Wash Generating Station generates about 3 GWh of electricity per year.

How many homes can San Dimas Wash Generating Station power?

Its output is enough to supply roughly 857 homes.

Who operates San Dimas Wash Generating Station?

San Dimas Wash Generating Station is operated by San Gabriel Valley Mun Wtr Dt.

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