Big Dan Hole Pond Dam dam
Big Dan Hole Pond Dam
Big Dan Hole Pond Dam, located in Ossipee, New Hampshire, is a concrete dam with a primary purpose of recreation. Completed in 1910, this structure stands at a height of 12.5 feet and spans 114 feet in length. The dam holds a normal storage capacity of 1200 acre-feet, with a maximum storage of 1810 acre-feet, serving the Dan Hole River and contributing to a surface area of 443 acres. Despite its age, the dam is state-regulated, inspected, and enforced by the NHDES DAM BUREAU, ensuring its safety and compliance with regulations.
The condition assessment of Big Dan Hole Pond Dam is currently rated as poor, with a significant hazard potential. The last inspection, conducted in October 2018, revealed the need for improvements to the structure. The dam's emergency action plan (EAP) was last revised in February 2020, indicating ongoing efforts to address safety concerns and enhance risk management measures. With a moderate risk assessment score of 3, stakeholders are actively monitoring and implementing necessary precautions to ensure the dam's reliability and resilience in the face of potential climate and water resource challenges.
As a significant recreational landmark in Carroll County, New Hampshire, Big Dan Hole Pond Dam plays a vital role in providing water-based activities for local residents and visitors alike. With its unique design and historical significance, the dam continues to be a focal point for water resource and climate enthusiasts interested in the intersection of infrastructure development, environmental stewardship, and public safety. Ongoing efforts to maintain and improve the dam underscore the importance of proactive risk management and sustainable water resource management practices in ensuring the long-term viability of this essential 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 Big Dan Hole Pond Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Bearcamp River At South Tamworth | 164 cfs | → |
| Saco River Near Conway | 1,420 cfs | → |
| Saco River At Cornish | 7,160 cfs | → |
| Pemigewasset River At Plymouth | 1,690 cfs | → |
| Winnipesaukee River At Tilton | 1,610 cfs | → |
| Pemigewasset River At Woodstock | 681 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Big Dan Hole Pond Dam.
Boat launches
- Pine River Boat Launch
- Duncan Lake Boat Launch
- Lake Winnipesaukee Boat Launch
- White Pond Boat Launch
- Mirror Lake Boat Launch
Campgrounds
Paddle runs
- Thornton Railroad Bridge To Bridgewater/Bristol Town Line
- Woodstock/Thornton Town Line To Thornton Railroad Bridge
- Begins In Franklin To Sewall's Island
- Sewall's Island To Manchester Street Bridge
- Headwaters At Profile Lake To Southern Boundary Of Franconia Notch State Park
Track Big Dan Hole Pond Dam 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 Big Dan Hole Pond Dam
Where does the data for Big Dan Hole Pond Dam 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 Big Dan Hole Pond Dam.