Hydroelectric Power Plants in New Hampshire
Every operating hydroelectric power plant in New Hampshire on EIA-860M for 2026-07: 32 plants, 88 generating units and 530 MW of nameplate capacity across 7 counties, most of it inside ISO New England.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Plants
- 32
- 88 generating units
- Nameplate capacity
- 530 MW
- Counties
- 7
- Grid operator
- ISO New England
- covers most of these plants
Map of hydroelectric power plants in New Hampshire
Every one of the 32 plants is drawn at the coordinate EIA files for it.
Loading map…
- Hydro · 32
List of hydroelectric power plants in New Hampshire
Sort by any column. Capacity is nameplate, summed across every generating unit EIA lists at the site.
| S C MooreConventional Hydroelectric | Great River Hydro, LLC | Grafton | 195.4 | 5 | 1957 | Operating |
| ComerfordConventional Hydroelectric | Great River Hydro, LLC | Grafton | 167.8 | 4 | 1930 | Operating |
| Berlin Gorham2 technologies | Great Lakes Hydro America LLC | Coos | 44.3 | 22 | 1914 | Operating |
| AmoskeagConventional Hydroelectric | Central Rivers Power NH, LLC | Hillsborough | 16 | 3 | 1922 | Operating |
| Smith (NH)Conventional Hydroelectric | Central Rivers Power NH, LLC | Coos | 15 | 1 | 1948 | Operating |
| Garvins FallsConventional Hydroelectric | Central Rivers Power NH, LLC | Merrimack | 12.4 | 4 | 1925 | Operating |
| Pontook Hydro FacilityConventional Hydroelectric | Pontook Operating LP | Coos | 10.5 | 3 | 1986 | Operating |
| Ayers IslandConventional Hydroelectric | Central Rivers Power NH, LLC | Grafton | 8.4 | 3 | 1925 | Operating |
| Eastman FallsConventional Hydroelectric | Central Rivers Power NH, LLC | Merrimack | 6.4 | 2 | 1937 | Operating |
| Dodge Falls AssociatesConventional Hydroelectric | Dodge Falls Associates LP | Grafton | 5 | 1 | 1990 | Operating |
| Penacook Lower FallsConventional Hydroelectric | Briar-Hydro Associates | Merrimack | 4.6 | 1 | 1983 | Operating |
| Rolfe Canal HydroConventional Hydroelectric | Briar-Hydro Associates | Merrimack | 4.3 | 1 | 1987 | Operating |
| Gregg FallsConventional Hydroelectric | Eagle Creek Renewable Energy, LLC | Hillsborough | 3.5 | 2 | 1985 | Operating |
| Penacook Upper Falls HydroConventional Hydroelectric | Briar-Hydro Associates | Merrimack | 3.4 | 1 | 1986 | Operating |
| JackmanConventional Hydroelectric | Central Rivers Power NH, LLC | Hillsborough | 3.2 | 1 | 1926 | Operating |
| Mine Falls Generating StationConventional Hydroelectric | City of Nashua - (NH) | Hillsborough | 3 | 2 | 1985 | Operating |
| Errol Hydroelectric ProjectConventional Hydroelectric | Errol Hydroelectric Co LLC | Coos | 3 | 1 | 1986 | Operating |
| Pembroke HydroConventional Hydroelectric | Eagle Creek Renewable Energy, LLC | Merrimack | 2.7 | 1 | 1985 | Operating |
| Clement Dam Hydro LLCConventional Hydroelectric | Eagle Creek Renewable Energy, LLC | Belknap | 2.4 | 1 | 1984 | Operating |
| GorhamConventional Hydroelectric | Central Rivers Power NH, LLC | Coos | 2.2 | 4 | 1917 | Operating |
| Stevens Mills DamConventional Hydroelectric | Eagle Creek Renewable Energy, LLC | Merrimack | 1.9 | 2 | 1985 | Operating |
| China Mill HydroConventional Hydroelectric | New Hampshire Hydro Associates | Merrimack | 1.7 | 1 | 1981 | Operating |
| HooksettConventional Hydroelectric | Central Rivers Power NH, LLC | Merrimack | 1.6 | 1 | 1927 | Operating |
| Mascoma HydroConventional Hydroelectric | Green Mountain Power Corp | Grafton | 1.5 | 3 | 1988 | Operating |
| Milton HydroConventional Hydroelectric | SFR Hydro Cor | Strafford | 1.4 | 4 | 1914 | Operating |
| Newfound HydroelectricConventional Hydroelectric | Eagle Creek Renewable Energy, LLC | Grafton | 1.4 | 2 | 1983 | Operating |
| RollinsfordConventional Hydroelectric | Green Mountain Power Corp | Strafford | 1.4 | 2 | 1986 | Operating |
| Somersworth Lower Great DamConventional Hydroelectric | Green Mountain Power Corp | Strafford | 1.3 | 1 | 1985 | Operating |
| Hillsborough HosieryConventional Hydroelectric | Silverstreet Hydro | Hillsborough | 1.2 | 2 | 1989 | Operating |
| Lower Village Water Power ProjectConventional Hydroelectric | Sugar River Power LLC | Sullivan | 1.2 | 2 | 1995 | Operating |
| Lochmere Hydroelectric PlantConventional Hydroelectric | Eagle Creek Renewable Energy, LLC | Belknap | 1.2 | 4 | 1984 | Operating |
| EHC West HopkintonConventional Hydroelectric | Green Mountain Power Corp | Merrimack | 1 | 1 | 1985 | Operating |
Largest hydroelectric power plants in New Hampshire
- 1S C MooreGrafton County, New Hampshire195.4 MW
- 2ComerfordGrafton County, New Hampshire167.8 MW
- 3Berlin GorhamCoos County, New Hampshire44.3 MW
- 4AmoskeagHillsborough County, New Hampshire16 MW
- 5Smith (NH)Coos County, New Hampshire15 MW
- 6Garvins FallsMerrimack County, New Hampshire12.4 MW
- 7Pontook Hydro FacilityCoos County, New Hampshire10.5 MW
- 8Ayers IslandGrafton County, New Hampshire8.4 MW
- 9Eastman FallsMerrimack County, New Hampshire6.4 MW
- 10Dodge Falls AssociatesGrafton County, New Hampshire5 MW
Hydroelectric power plants by county in New Hampshire
The county EIA files against each plant. It is the fastest way to find the plant nearest a given town.
| County | Plants | Nameplate MW |
|---|---|---|
| Grafton | 6 | 379.5 |
| Coos | 5 | 75 |
| Merrimack | 10 | 40 |
| Hillsborough | 5 | 26.9 |
| Strafford | 3 | 4.1 |
| Belknap | 2 | 3.6 |
| Sullivan | 1 | 1.2 |
Hydroelectric Power Plants in New Hampshire: FAQ
- How many hydroelectric power plants are in New Hampshire?
- 32, with 530 MW of nameplate capacity between them, spread over 7 counties. That is the EIA-860M operating count for 2026-07.
- Is there a map of New Hampshire hydroelectric power plants?
- Yes — the map above. Each dot is one hydroelectric power plant, sized by nameplate capacity and placed at the coordinates EIA files for it.
- Which is the largest hydroelectric power plant in New Hampshire?
- S C Moore, at 195 MW. The table is sorted largest first, so the rest follow it.
- Is there a hydroelectric power plant near me in New Hampshire?
- The county roll-up below groups every plant by county, which is the quickest way to find the one closest to a given town.
- Which grid operator runs New Hampshire's hydroelectric power plants?
- Most of them sit inside ISO New England, according to the balancing-authority code EIA files against each plant. Live conditions for that market are on this site.
- How current is this, and what is left out?
- EIA-860M for 2026-07. Conventional hydroelectric. Pumped storage is counted separately. Plants below 1 MW are not surveyed by EIA and so are absent; retirements and additions after 2026-07 arrive with the next monthly release.