Synnes Dam; Marvin 2 Reservoir Report
Last Updated: December 6, 2025
Synnes Dam; Marvin 2, also known as Wetland 1, is a private-owned earth dam located in Dunn, North Dakota.
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Summary
With a height of 15.6 feet and a length of 630 feet, this dam was completed in 2012 and serves as a fish and wildlife pond with a storage capacity of 89.4 acre-feet. The dam is primarily regulated by the North Dakota State Water Commission and is designed by the US Fish and Wildlife Service.
The dam features an uncontrolled spillway with a width of 125 feet and has a low hazard potential with a moderate risk assessment rating. Although the condition of the dam is not rated, it meets the necessary state inspection, permitting, and enforcement requirements. Synnes Dam plays a crucial role in providing habitat for fish and wildlife in the area, contributing to the overall conservation efforts in North Dakota.
Overall, Synnes Dam; Marvin 2 is a significant water resource structure that serves as a vital component in the management of fish and wildlife populations in the region. With its completion in 2012, this earth dam has been instrumental in providing a sustainable habitat for various species, while also meeting the necessary regulatory standards set by the state. Its strategic location along the Knife River-TR ensures the preservation of natural ecosystems and contributes to the overall environmental sustainability efforts in Dunn County.
Year Completed |
2012 |
Dam Length |
630 |
Dam Height |
15.6 |
River Or Stream |
KNIFE RIVER-TR |
Primary Dam Type |
Earth |
Surface Area |
9.8 |
Nid Storage |
89.4 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
16 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Knife River At Manning
|
2cfs |
Knife River Nr Golden Valley
|
27cfs |
Green River Nr New Hradec
|
1cfs |
Spring Creek At Zap
|
5cfs |
Heart River Nr South Heart
|
6cfs |
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.
Synnes Dam; Marvin 2