Big Dan Hole Pond Dam Reservoir Report
Last Updated: December 15, 2025
Big Dan Hole Pond Dam, located in Ossipee, New Hampshire, is a concrete dam with a primary purpose of recreation.
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Summary
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.
Year Completed |
1910 |
Dam Length |
114 |
Dam Height |
12.5 |
River Or Stream |
DAN HOLE RIVER |
Primary Dam Type |
Concrete |
Surface Area |
443 |
Drainage Area |
5.68 |
Nid Storage |
1810 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
13 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Bearcamp River At South Tamworth
|
152cfs |
Saco River Near Conway
|
315cfs |
Saco River At Cornish
|
1020cfs |
Pemigewasset River At Plymouth
|
461cfs |
Winnipesaukee River At Tilton
|
85cfs |
Pemigewasset River At Woodstock
|
164cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
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. Investigations and studies are necessary.
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.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams 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, environment 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.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Big Dan Hole Pond Dam
Pine River Boat Launch