Three Mile Creek Reservoir Reservoir Report
Last Updated: December 13, 2025
Three Mile Creek Reservoir, located in Harney, Oregon, serves as a vital source of irrigation for the surrounding area since its completion in 1946.
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Summary
With a capacity of 1600 acre-feet and covering 34 acres, this Earth-type dam stands at a height of 12 feet, facilitating the controlled release of water through slide gates to support agricultural activities. The reservoir is regulated by the Oregon Water Resources Department and undergoes regular inspections to ensure its functionality and safety.
Despite its low hazard potential, Three Mile Creek Reservoir plays a crucial role in supporting the local economy and sustaining the agricultural community in the region. The reservoir's maximum discharge capacity of 420 cubic feet per second ensures efficient water management during periods of high demand. Its strategic location on Three Mile Creek, combined with its reliable infrastructure, makes it a key asset for water resource and climate enthusiasts interested in sustainable irrigation practices in Oregon.
As a private-owned facility, the reservoir remains an essential water management structure in the area, demonstrating the ongoing commitment to efficient water use and conservation. With its modest footprint and reliable operation, Three Mile Creek Reservoir represents a model for responsible water resource management and serves as an example of how local stakeholders can work together to maintain a valuable water supply in a changing climate environment.
Year Completed |
1946 |
Dam Length |
8000 |
Dam Height |
12 |
River Or Stream |
THREE MILE CREEK |
Primary Dam Type |
Earth |
Surface Area |
34 |
Hydraulic Height |
10 |
Drainage Area |
50 |
Nid Storage |
1600 |
Structural Height |
14 |
Outlet Gates |
Slide (sluice gate) |
Hazard Potential |
Low |
Nid Height |
14 |
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.
Three Mile Creek Reservoir
Threemile Creek
Home Creek