Long Pond dam
Long Pond
Long Pond in Hancock, Maine, is a significant water resource managed by the local government for multiple purposes, including hydroelectric power generation, fire protection, stock and small fish pond, fish and wildlife habitat, flood risk reduction, and water supply. The dam, constructed in 1930, is primarily made of stone and stands at a height of 8 feet with a hydraulic height of 6 feet. The reservoir has a storage capacity of 3,480 acre-feet and a surface area of 897 acres, making it an essential asset for water management in the region.
Despite its importance, Long Pond's dam is classified as having a significant hazard potential and is rated as being in poor condition based on a 2017 assessment. The dam has a spillway width of 8 feet and is regulated by the Maine Emergency Management Agency (MEMA). Regular inspections are conducted, with the last one taking place in May 2017, and emergency action plans are in place to address any potential risks associated with the dam. The site is a focal point for water resource and climate enthusiasts due to its role in supporting various environmental and human needs while also facing challenges in maintaining its structural integrity.
For those interested in water resource management and climate resilience, Long Pond offers a case study in balancing the benefits of a multi-purpose reservoir with the challenges of maintaining aging infrastructure. With its historical significance dating back to the early 20th century, the dam at Long Pond represents a unique blend of hydroelectric power generation, water supply, and environmental conservation efforts. Monitoring and addressing the structural integrity and hazard potential of the dam remain crucial for ensuring the long-term sustainability of this vital water resource in Maine's landscape.
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 Long Pond -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Narraguagus River At Cherryfield | 404 cfs | → |
| Ducktrap River Near Lincolnville | 45 cfs | → |
| East Br Bear Brook Near Beddington | 0 cfs | → |
| West Br Bear Brook Near Beddington | 1 cfs | → |
| Kenduskeag Stream Near Bangor | 344 cfs | → |
| Libby Brook Near Northfield | 10 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Long Pond.
Boat launches
- Eagle Lake Carriage Road Bar Harbor
- Great Cove Drive 116, Brooklin
- Town Landing Sedgwick
- Little Deer Isle Road 204, Deer Isle
- Acadia Highway 1117, East Orland
- Water Street, Castine
Track Long Pond 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 Long Pond
Where does the data for Long Pond 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 Significant 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 Long Pond.