Ester Lake (Phillips) Reservoir Report
Nearby: Early Bird Wild Horse Dam Pd
Last Updated: December 5, 2025
Ester Lake (Phillips) is a state-owned reservoir located in Saco, Montana, with a primary purpose of irrigation.
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Summary
The dam, completed in 1954, is an earth-type structure standing at a height of 16.7 feet and with a maximum storage capacity of 758 acre-feet. The lake covers a surface area of 137 acres and is fed by the Big Warm Spring Creek.
Managed by the Montana Department of Natural Resources and Conservation (DNRC), Ester Lake is regulated, inspected, and enforced by the state, ensuring its safety and functionality for irrigation purposes. The dam is classified as having a significant hazard potential, although its condition assessment is currently listed as "Not Rated." With no emergency action plan in place, there is room for improvement in ensuring the safety of the surrounding area in case of a dam failure.
Located in Congressional District 00, Montana, Ester Lake serves as a vital resource for the local community and agriculture industry. As water resource and climate enthusiasts, it is crucial to monitor the condition and management of Ester Lake to ensure its continued effectiveness in providing irrigation water while also addressing any potential risks and safety concerns associated with the dam.
Year Completed |
1954 |
Dam Length |
600 |
Dam Height |
16.7 |
River Or Stream |
BIG WARM SPRING CREEK |
Primary Dam Type |
Earth |
Surface Area |
137 |
Hydraulic Height |
11.5 |
Nid Storage |
758 |
Hazard Potential |
Significant |
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.
Ester Lake (Phillips)