Lower Dry Fork Reservoir Report
Nearby: Upper Dry Fork Eggebrecht Dam
Last Updated: January 11, 2026
Lower Dry Fork is a federal-owned irrigation dam located in Sanders, Montana, managed by the Bureau of Indian Affairs.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1921, this Earth dam stands at a structural height of 37 feet and has a length of 2700 feet, providing a normal storage capacity of 3860 acre-feet for irrigation purposes. Despite its age, the dam has a high hazard potential and is classified as a very high risk due to its condition assessment not being available.
The Lower Dry Fork dam is situated on the Dry Fork river and is under the jurisdiction of the DOI BIA. With a controlled spillway type and a high-risk designation, this dam poses a significant threat in case of failure. The last inspection was conducted in 2011, with a 5-year inspection frequency, indicating the importance of regular monitoring and maintenance to ensure the safety of the surrounding area and water resources.
For water resource and climate enthusiasts, the Lower Dry Fork dam serves as a critical infrastructure for irrigation in the region, highlighting the intersection of water management, infrastructure maintenance, and environmental risk assessment. As discussions on climate change intensify, the resilience and safety of dams like Lower Dry Fork will be crucial in adapting to changing environmental conditions and ensuring sustainable water resource management for the future.
Year Completed |
1921 |
Dam Length |
2700 |
River Or Stream |
DRY FORK |
Primary Dam Type |
Earth |
Nid Storage |
3860 |
Structural Height |
37 |
Hazard Potential |
High |
Nid Height |
37 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Mill Cr Ab Bassoo Cr Nr Niarada Mt
|
2cfs |
Flathead River Near Polson Mt
|
12200cfs |
Clark Fork Near Plains Mt
|
18200cfs |
Flathead River At Perma Mt
|
12300cfs |
Thompson River Near Thompson Falls Mt
|
394cfs |
Prospect Creek At Thompson Falls Mt
|
296cfs |
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.
Lower Dry Fork