North Twin dam
North Twin
North Twin, also known as Elbow Lake Dam, is a hydroelectric facility located in Millinocket, Maine, along the West Branch Penobscot River. Constructed in 1934, this dam stands at a height of 35 feet and has a storage capacity of 346,000 acre-feet, serving multiple purposes such as flood risk reduction, recreation, and water supply. With a spillway width of 100 feet and a maximum discharge of 72,000 cubic feet per second, this dam plays a crucial role in managing water resources in the region.
Despite not being state-regulated, North Twin poses a high hazard potential, with a risk assessment rating of very high. Emergency action plans have been prepared, and the dam is inspected annually to ensure its structural integrity and safety. Managed by the Federal Energy Regulatory Commission, this dam serves as a key infrastructure for generating hydroelectric power while also supporting fish and wildlife habitats in the area. With its controlled spillway and outlet gates, North Twin is an essential component of the region's water resource management system.
Surrounded by scenic landscapes and offering recreational opportunities, North Twin Dam is a significant landmark in the Penobscot County, Maine. Its strategic location and design make it a vital asset for the community, balancing the need for energy production with environmental conservation and water management. As climate change continues to impact water resources, dams like North Twin play a crucial role in adapting to changing conditions and ensuring sustainable use of water for generations to come.
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 North Twin -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| East Branch Penobscot River At Grindstone | 2,930 cfs | → |
| Mattawamkeag River Near Mattawamkeag | 3,080 cfs | → |
| Piscataquis River At Medford | 2,470 cfs | → |
| Penobscot River At West Enfield | 16,000 cfs | → |
| Seboeis River Near Shin Pond | 430 cfs | → |
| Piscataquis River Near Dover-Foxcroft | 432 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near North Twin .
Boat launches
- Trail Penobscot County
- Landing Road Penobscot County
- Mike Michaud Trail Millinocket
- Medway Road Millinocket
- Golden Road Maine
- Fredericka's Way Maine
Campgrounds
Paddle runs
- Ambajejus Falls To The End Of North And South Twin Lakes
- Hay Brook To Bridge Above Medway At State Route 157
- Headwaters To Confluence With West Branch Penobscot River
- Headwaters To Confluence With Penobscot River, East Branch
- Headwaters To Mouth At West Branch Pleasant River
- Bowlin Camps To Hay Brook
Track North Twin 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 North Twin
Where does the data for North Twin 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 High 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 North Twin .