MORMON FLAT
OperatingHydro power plant
- Capacity
- 67 MW
- Primary fuel
- Hydro
- County
- Maricopa County
- Operator
- SALT RIVER PROJECT
- Status
- Operating
- Commissioned
- 1926
- EIA plant ID
- 148
- Generators
- 2
- Technology
- Hydroelectric Pumped Storage
- Net generation (2024)
- 54.3 GWh
- Capacity factor (2024, EIA nameplate)
- 9.7%
- Data vintage
- EIA-860 2024 final; EIA-923 2022-2024 final
- Coordinates
- 33.5536, -111.4431
MORMON FLAT, a 67 MW Hydro power plant in Maricopa County, Arizona. Operated by SALT RIVER PROJECT, commissioned 1926.
How MORMON FLAT compares
With 67 MW of capacity, MORMON FLAT ranks 42nd among the 71 operating power plants Bywatts maps in Arizona and 5th of the 9 operating Hydro plants in the state. It accounts for about 2.3% of Arizona's operating Hydro capacity and 0.2% of all operating capacity in the state. Nationally it is the 240th-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1926, it is older than 98% of the 69 operating Arizona plants with a recorded commissioning year. Its operator, SALT RIVER PROJECT, runs 11 operating plants in Arizona totaling 5,203 MW. It shares Maricopa County with 28 other operating plants, including PALO VERDE and SANTAN.
EIA-860 lists 2 generators at the site with 64 MW of nameplate capacity, mainly hydroelectric pumped storage technology. Net generation was 54.3 GWh in 2024 (a 9.7% capacity factor), up 40% from 2022. Its generators came online between 1926 and 1971.
Grid neighborhood
The nearest named substation is MORMON FLAT DAM (115 kV), about 0.1 miles away; the closest transmission line found within 10 miles is a 115 kV line owned by SALT RIVER PROJECT, about 0.1 miles away. Another 5 operating power plants totaling 1,556 MW sit within 25 miles; the largest is SANTAN (1,339 MW, Natural Gas). Within 50 miles are 6 mapped data centers; the nearest is Centersquare Phoenix (PHX3) in Mesa, about 25.7 miles away.
Computed by Bywatts from HIFLD power plant, substation and transmission line records, EIA-860/923 survey data and PeeringDB data center locations; distances are straight-line. Sources and methodology
Weather peril exposure
MORMON FLAT is a 67 MW hydro power plant in Maricopa County, AZ, operated by SALT RIVER PROJECT, commissioned in 1926. Maricopa County carries elevated modeled catastrophe exposure in the FEMA National Risk Index, scoring 2.7 of 5 at the 42nd national percentile. Wildfire is the leading peril, rated Relatively High by FEMA at the 85th percentile.
The Bywatts loss layer is calibrated to solar PV hardware, so it is not applied to a hydro plant. The ratings below are the FEMA National Risk Index county hazard ratings for this location.
Maricopa County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Wildfire | Relatively High | 85th | 4.4 of 5 | <0.01 |
| Riverine flooding | Very High | 85th | 4.4 of 5 | 8.5 |
| Heat wave | Very High | 71st | 3.9 of 5 | 19.8 |
| Hail | Very High | 56th | 3.2 of 5 | 0.28 |
| Earthquake | Relatively Moderate | 49th | 3.0 of 5 | 0.01 |
| Strong wind | Very High | 19th | 1.8 of 5 | 1.4 |
| Tornado | Relatively Moderate | 7th | 1.3 of 5 | 0.57 |
| Lightning | Relatively High | 3rd | 1.1 of 5 | 32.3 |
| Winter weather | Relatively Low | 1st | 1.1 of 5 | 0.57 |
| Hurricane | Very Low | 0th | 1.0 of 5 | 0.01 |
Perils not assessed in Maricopa County
These perils carry no usable National Risk Index figure for this county, so they are excluded from the scoring rather than scored zero. A zero would claim the peril was assessed and found benign.
| Peril | Why it is not scored |
|---|---|
| Coastal flooding | FEMA rating is "Not Applicable" for this county |
| Ice storm | FEMA rating is "Not Applicable" for this county |
Model hail, wind and flood exposure for Maricopa County in the weather risk calculator
Ratings are the FEMA National Risk Index county hazard ratings; the peril score is a Bywatts transform of the FEMA national percentile. Full data sources and the solar vulnerability methodology are in the weather risk calculator.
Modeled estimate for screening and negotiation. Built from FEMA National Risk Index county hazard data and a solar vulnerability layer documented above. Not a quote, a binder, or actuarial advice, and not a substitute for a carrier's own model. Hazard data: FEMA National Risk Index December 2025, synced 2026-07-24. Resolution is county level, not site level.