Averill Reservoir Report
Nearby: Hubbart Little Bitterroot
Last Updated: December 5, 2025
Averill is a key irrigation dam located in Flathead, Montana, along the TR-Little Bitterroot River.
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Summary
Built in 1964 by the USDA NRCS, this earth dam stands at a height of 32 feet and has a storage capacity of 214 acre-feet, with a normal storage level of 135 acre-feet. The dam serves the primary purpose of irrigation, supporting the local agriculture industry in the region.
Managed by the DNRC and subject to state regulations, Averill is deemed to have low hazard potential and has not been rated for its condition assessment. Despite its age, the dam has not undergone any major modifications and lacks a formal Emergency Action Plan. With a maximum discharge capacity of 63 cubic feet per second and a spillway width of 24 feet, Averill plays a crucial role in water resource management in the area, highlighting the importance of continued monitoring and maintenance to ensure its effective operation in the face of changing climate conditions.
As a structure under the jurisdiction of the Seattle District and Congressional District 00 in Montana, Averill stands as a testament to the collaboration between local government agencies and federal entities like the USDA NRCS in managing water resources for irrigation purposes. With its presence supporting agriculture in the region, this dam serves as a vital component in the sustainable utilization of water in the face of evolving climate challenges, emphasizing the need for ongoing oversight and investment in infrastructure to safeguard against potential risks and ensure the resilience of water resources for future generations.
Year Completed |
1964 |
Dam Length |
225 |
Dam Height |
32 |
River Or Stream |
TR-LITTLE BITTERROOT RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
28 |
Drainage Area |
2.97 |
Nid Storage |
214 |
Hazard Potential |
Low |
Nid Height |
32 |
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.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
McGregor Lake
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McGregor Lake Campground
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Logan State Park
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Logan Park Campground
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Averill