Green Lake dam
Green Lake
Green Lake, a private hydroelectric dam located in Ellsworth, Maine, is a historic structure completed in 1911. With a dam height of 7.5 feet and a storage capacity of 107,000 acre-feet, this masonry dam serves multiple purposes including fire protection, stock pond, fish and wildlife habitat, recreation, and water supply. The dam sits on Reeds Brook and has a surface area of 2,989 acres, with a drainage area of 58 square miles.
Managed by the Federal Energy Regulatory Commission, Green Lake's spillway type is uncontrolled with a width of 80 feet. The dam is considered to have low hazard potential and a moderate risk rating. An emergency action plan was last revised in 2010, with inspection frequency set at every 3 years. The structure, although not currently assessed for condition, continues to be a significant feature in the region's water resource and climate management.
Overall, Green Lake stands as a testament to the intersection of human ingenuity and environmental stewardship, providing essential services while maintaining a balance with nature. Its rich history, diverse functions, and regulatory oversight make it a fascinating subject for water resource and climate enthusiasts seeking to understand the complex dynamics of dam infrastructure in the context of sustainable development and environmental protection.
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 Green Lake -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| West Br Bear Brook Near Beddington | 1 cfs | → |
| East Br Bear Brook Near Beddington | 0 cfs | → |
| Kenduskeag Stream Near Bangor | 251 cfs | → |
| Narraguagus River At Cherryfield | 338 cfs | → |
| Ducktrap River Near Lincolnville | 35 cfs | → |
| Libby Brook Near Northfield | 8 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Green Lake .
Boat launches
- Camp Roosevelt Road 18, Clifton
- Craig Pond Trail 79, Orland
- Acadia Highway 1117, East Orland
- Snowmobile Trail 7c Holden Holden
- Eagle Lake Carriage Road Bar Harbor
- Mountain View Lane 2, Beddington
Track Green Lake 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 Green Lake
Where does the data for Green Lake 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 Green Lake .