Summary
Completed in 1980, this private earth dam stands at a height of 17 feet and has a storage capacity of 900 acre-feet. With a surface area of 132 acres, the dam plays a crucial role in supporting agriculture in the area, highlighting its primary purpose as irrigation.
Despite its low hazard potential, Offerdahl-Johnson Dam is regulated and inspected by the Montana Department of Natural Resources and Conservation (DNRC). The dam has not been rated for its condition but has demonstrated its reliability in providing a consistent water supply for the surrounding community. With no associated structures and a lack of detailed risk assessment data, the dam continues to play a key role in water resource management in Phillips County.
The dam's location in Saco, Montana, under the jurisdiction of the state, underscores the importance of proper maintenance and oversight to ensure its continued functionality. As water resource and climate enthusiasts, it is essential to monitor Offerdahl-Johnson Dam's condition and support efforts to sustainably manage this critical water infrastructure for the benefit of the local community and the environment.
Year Completed |
1980 |
Dam Length |
1840 |
Dam Height |
17 |
River Or Stream |
LITTLE SEVEN MILE CREEK |
Primary Dam Type |
Earth |
Surface Area |
132 |
Hydraulic Height |
17 |
Nid Storage |
900 |
Hazard Potential |
Low |
Nid Height |
17 |
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.
Offerdahl-Johnson Dam