Ammonoosuc River dam
Ammonoosuc River
The Ammonoosuc River, located in Bath, New Hampshire, is a vital water resource with a primary purpose of hydroelectric power generation. The concrete dam on the river, completed in 1900, stands at a height of 17 feet and has a length of 365 feet, with a storage capacity of 352 acre-feet. The dam regulates the flow of the river and has a low hazard potential, ensuring the safety and stability of the surrounding area.
Managed by the Federal Energy Regulatory Commission, the Ammonoosuc River dam undergoes regular inspections to ensure its structural integrity. With a moderate risk assessment rating, the dam is equipped with a slide (sluice gate) outlet gate and an uncontrolled spillway. The river has a drainage area of 395 square miles and a maximum discharge capacity of 40,000 cubic feet per second, making it a significant contributor to the region's water supply and ecosystem.
Climate and water resource enthusiasts will find the Ammonoosuc River dam an intriguing structure that plays a crucial role in harnessing hydroelectric power while maintaining environmental and safety standards. Its historical significance, engineering design, and impact on the local community make it a noteworthy feature of New Hampshire's water infrastructure.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Ammonoosuc River -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Connecticut River At Wells River | 4,490 cfs | → |
| Wells River At Wells River | 207 cfs | → |
| Passumpsic River At Passumpsic | 942 cfs | → |
| East Branch Pemigewasset River At Lincoln | 465 cfs | → |
| Ammonoosuc River At Bethlehem Junction | 267 cfs | → |
| Sleepers River (Site W-5) Near St. Johnsbury | 87 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Ammonoosuc River .
Boat launches
- French Pond Boat Launch
- Lyman Road Lyman
- Partridge Lake Boat Launch
- Olivarian Road 99, Benton
- Oliverian Boating Site
- Old Waterford Road Littleton
Campgrounds
- Harkdale Farm Campsite
- Wildwood Campground
- Kinsman Pond Tentsite
- Kinsman Pond Shelter
- Eliza Brook Shelter
- Coppermine Shelter
Paddle runs
- Headwaters At Profile Lake To Southern Boundary Of Franconia Notch State Park
- Woodstock/Thornton Town Line To Thornton Railroad Bridge
- Thornton Railroad Bridge To Bridgewater/Bristol Town Line
- Headwaters To Folsom Brook
- Source Above Fr 55 To Proclamation Boundary (Stony Brook)
- Proclamation Boundary To Proclamation Boundary
Track Ammonoosuc River in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Ammonoosuc River
Where does the data for Ammonoosuc River come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Ammonoosuc River .