Summary
Ignatius, Montana, along Mission Creek. Managed by the Bureau of Indian Affairs, this earth dam stands at 83 feet tall and spans 1848 feet in length, with a storage capacity of 7000 acre-feet. Completed in 1935, Mission serves primarily for irrigation purposes, with additional recreational benefits.
Despite its age, Mission has a high hazard potential and a very high risk assessment rating. The dam has not undergone recent condition assessments, but emergency action plans have been prepared and updated. The last inspection took place in July 2011, with a recommended inspection frequency of every 5 years. With its controlled spillway type and location in a high-risk area, Mission requires careful monitoring and management to ensure public safety and water resource sustainability.
Enthusiasts of water resources and climate will find Mission to be a fascinating case study in dam management and risk assessment. With its historical significance, critical irrigation function, and high hazard potential, Mission represents both the challenges and opportunities in maintaining infrastructure for water supply in a changing climate. As climate impacts continue to pose threats to water resources, the management and maintenance of structures like Mission will be crucial for ensuring the resilience of water systems in the future.
Year Completed |
1935 |
Dam Length |
1848 |
River Or Stream |
MISSION CREEK |
Primary Dam Type |
Earth |
Nid Storage |
7000 |
Structural Height |
83 |
Hazard Potential |
High |
Nid Height |
83 |
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.
Mission