Thyberg Dam; Marvelin Reservoir Report
Last Updated: December 14, 2025
Thyberg Dam, located in McLean County, North Dakota, is a marvel of engineering designed by the USDA NRCS and completed in 1967.
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Summary
This private-owned Earth dam, with a height of 25 feet and a length of 250 feet, serves as a Fish and Wildlife Pond along the Missouri-TR River. With a storage capacity of 43 acre-feet and a surface area of 4 acres, Thyberg Dam provides critical habitat for local wildlife and supports conservation efforts in the region.
Despite being classified as having a low hazard potential, Thyberg Dam plays a crucial role in managing water resources and supporting the ecosystem in the area. The spillway, with a width of 50 feet, helps regulate water flow during periods of high discharge, ensuring the stability and integrity of the dam. While its condition is currently assessed as "Not Rated," regular inspections are conducted to ensure the safety and functionality of the structure.
In the realm of water resource and climate enthusiasts, Thyberg Dam stands as a testament to the importance of sustainable infrastructure for supporting biodiversity and conservation efforts. With its moderate risk assessment and commitment to wildlife habitat preservation, this dam serves as a valuable resource for the local community and a shining example of responsible stewardship of our natural resources.
Year Completed |
1967 |
Dam Length |
250 |
Dam Height |
25 |
River Or Stream |
MISSOURI-TR |
Primary Dam Type |
Earth |
Surface Area |
4 |
Drainage Area |
0.31 |
Nid Storage |
43 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Knife River At Hazen
|
48cfs |
Square Butte Creek Below Center
|
2cfs |
Spring Creek At Zap
|
5cfs |
Sweetbriar Creek Nr Judson
|
3cfs |
Burnt Creek Nr Bismarck
|
9cfs |
Heart River Nr Mandan
|
101cfs |
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.
Thyberg Dam; Marvelin
Northern Boundary Of Knife River Indian Villages National Historic Site To Southern Boundary Of Knife River Indian Villages National Historic Site