Ottun #9 Reservoir Report
Nearby: Rowley Cb&O #1 Ottun #8
Last Updated: December 5, 2025
Ottun #9 is a privately owned earth dam in Big Horn, Montana, near the city of Hardin.
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Summary
Completed in 1950, this dam serves multiple purposes including fire protection, stock watering, and creating a small fish pond. With a height of 15 feet and a length of 200 feet, Ottun #9 has a storage capacity of 74 acre-feet, with a normal storage level of 29 acre-feet.
Located on TR-PERITSA CREEK, Ottun #9 is under the jurisdiction of the Montana Department of Natural Resources and Conservation (DNRC) and is subject to state regulation, inspection, and enforcement. The dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment. Although no emergency action plan (EAP) or inundation maps have been prepared for Ottun #9, the dam is regularly monitored to ensure its safety and compliance with regulatory standards.
For water resource and climate enthusiasts, Ottun #9 presents an interesting case study of a privately owned dam with multiple uses in a rural setting. Its location in a congressional district represented by Greg Gianforte (R) highlights the intersection of water resource management and political representation. With its low hazard potential and state-regulated status, Ottun #9 serves as a reminder of the importance of maintaining and monitoring dams for both safety and environmental impact in the face of changing climate conditions.
Year Completed |
1950 |
Dam Length |
200 |
Dam Height |
15 |
River Or Stream |
TR-PERITSA CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Nid Storage |
74 |
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.
Ottun #9