Grierson #1 Reservoir Report
Last Updated: December 8, 2025
Grierson #1 is a privately owned earth dam located in Treasure County, Montana, specifically in the city of Sanders.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1958, this dam serves multiple purposes including fire protection, stock watering, and providing a small fish pond. With a height of 15 feet and a length of 150 feet, the dam has a storage capacity of 64 acre-feet, with a normal storage level of 25 acre-feet.
Situated on the TR-FROSE-TO-DEATH CR river or stream, Grierson #1 is regulated by the Montana Department of Natural Resources and Conservation (DNRC). Despite being categorized as having a low hazard potential, the dam's condition has not been rated. The dam has not been inspected recently, and there is no available information on emergency action plans or risk management measures in place.
For water resource and climate enthusiasts, Grierson #1 presents an interesting case study of a privately owned earth dam in Montana with multiple functional purposes. The lack of recent inspections and condition assessments highlights the importance of ongoing maintenance and monitoring of such critical infrastructure, especially in the face of changing climate conditions. Additionally, the absence of information on emergency preparedness and risk management underscores the need for comprehensive planning and protocols to ensure the safety and resilience of dams like Grierson #1 in the event of emergencies or extreme weather events.
Year Completed |
1958 |
Dam Length |
150 |
Dam Height |
15 |
River Or Stream |
TR-FROSE-TO-DEATH CR |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Nid Storage |
64 |
Hazard Potential |
Low |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
Grierson #1