Long Pond dam
Long Pond
Long Pond, located in Penobscot, Maine, is a privately-owned reservoir that serves the primary purpose of flood risk reduction. Built in 1915, this earth dam stands at a height of 12 feet and has a hydraulic height of 8 feet, with a length of 150 feet. With a storage capacity of 1794 acre-feet and a normal storage level of 1410 acre-feet, Long Pond covers a surface area of 506 acres and drains an area of 8 square miles through the Mattanawcook Stream.
Despite being classified as a low hazard potential dam, Long Pond is state regulated and subject to regular inspection, permitting, and enforcement by the Maine Emergency Management Agency. The last inspection of the dam was conducted in November 2007, with a condition assessment of "Not Rated". The reservoir has not been modified in recent years and does not have a designated Emergency Action Plan, but it meets state guidelines for dam safety.
Water resource and climate enthusiasts interested in Long Pond can appreciate its historical significance as a flood control structure in the region. The dam contributes to the management of water levels and mitigates flood risks along the Mattanawcook Stream, showcasing the intersection of human infrastructure with natural water systems in Maine. Further monitoring and assessment of the dam's condition and emergency preparedness may be necessary to ensure the continued safety and functionality of Long Pond for both water resource management and environmental conservation purposes.
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 |
|---|---|---|
| Penobscot River At West Enfield | 18,900 cfs | → |
| Mattawamkeag River Near Mattawamkeag | 4,440 cfs | → |
| Piscataquis River At Medford | 3,420 cfs | → |
| East Branch Penobscot River At Grindstone | 3,540 cfs | → |
| Grand Lake Stream At Grand Lake Stream | 321 cfs | → |
| West Br Bear Brook Near Beddington | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Long Pond.
Boat launches
- Folsom Pond Road 500, Lincoln
- Aldrich Point Road Lincoln
- Lake Street Lincoln
- West Broadway 735, Lincoln
- Dickey Moore Road 170, Medway
- Greenbush
Campgrounds
Paddle runs
- Hay Brook To Bridge Above Medway At State Route 157
- Ambajejus Falls To The End Of North And South Twin Lakes
- Headwaters To Mouth At West Branch Pleasant River
- Headwaters To Confluence With West Branch Penobscot River
- Headwaters To Confluence With Penobscot River, East Branch
- Bowlin Camps To Hay Brook
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 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 Long Pond.