Wolff Dam; Armon 4 Reservoir Report
Last Updated: December 14, 2025
Wolff Dam, also known as Armon 4, is a privately owned structure located in Mercer, North Dakota.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1961 by the USDA NRCS, this earth dam serves multiple purposes including fire protection, stock, and a small fish pond. The dam stands at a height of 19.5 feet and has a length of 1100 feet, with a storage capacity of 135 acre-feet and a surface area of 15 acres.
Managed by the North Dakota State Water Commission, Wolff Dam is regulated, permitted, inspected, and enforced by state authorities. Despite its low hazard potential, the dam poses a moderate risk, with a risk assessment rating of 3. With an uncontrolled spillway and no outlet gates, the dam's condition is currently unrated, and there is no emergency action plan in place. The surrounding area benefits from the dam's contribution to water resource management and climate resilience, making it a key asset in the region.
Overall, Wolff Dam plays a crucial role in maintaining water resources in the area and providing essential services such as fire protection and stock water supply. Its construction and management reflect the importance of sustainable water infrastructure for both human and environmental well-being, making it a significant site for water resource and climate enthusiasts to explore and appreciate.
Year Completed |
1961 |
Dam Length |
1100 |
Dam Height |
19.5 |
River Or Stream |
SPRING CREEK-TR |
Primary Dam Type |
Earth |
Surface Area |
15 |
Drainage Area |
2.11 |
Nid Storage |
135 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Knife River Nr Golden Valley
|
27cfs |
Spring Creek At Zap
|
5cfs |
Knife River At Hazen
|
48cfs |
Knife River At Manning
|
2cfs |
Deepwater Creek At Mouth Nr Raub
|
2cfs |
Heart River Nr Richardton
|
17cfs |
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.
Wolff Dam; Armon 4