Chevally Reservoir Reservoir Report
Nearby: Hawks Nest Reservoir Texas Basin
Last Updated: December 13, 2025
Chevally Reservoir, located in Malheur, Oregon, is a privately owned earth dam structure that was completed in 1933 for irrigation purposes along Cow Creek.
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Summary
With a capacity of 406 acre-feet, this reservoir covers a surface area of 60 acres and serves as a vital water resource for the surrounding area. The dam stands at 22 feet high and has a structural height of 30 feet, providing essential water storage for agricultural needs in the region.
Managed by the Oregon Water Resources Department, Chevally Reservoir is regulated, inspected, and enforced to ensure its safety and functionality. Despite being classified as having low hazard potential, regular inspections are conducted every six years to maintain its condition and assess any potential risks. The reservoir's emergency action plan status, risk assessment, and inundation maps are currently not specified, but the structure is designed to meet irrigation demands efficiently while adhering to regulatory guidelines.
With its strategic location and historical significance in supporting irrigation activities, Chevally Reservoir remains a crucial water management infrastructure in the area. The reservoir's presence contributes to the sustainable use of water resources for agricultural purposes and underscores the importance of proper dam maintenance and oversight to ensure the safety and reliability of water supply systems in the region.
Year Completed |
1933 |
Dam Length |
400 |
Dam Height |
22 |
River Or Stream |
COW CREEK, (OFFSTREAM) |
Primary Dam Type |
Earth |
Surface Area |
60 |
Hydraulic Height |
20 |
Drainage Area |
50 |
Nid Storage |
406 |
Structural Height |
30 |
Hazard Potential |
Low |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Owyhee River Nr Rome Or
|
189cfs |
Snake River Nr Murphy Id
|
6650cfs |
Owyhee River Below Owyhee Dam Or
|
30cfs |
Boise River At Caldwell
|
519cfs |
Dixie Drain Nr Wilder Id
|
52cfs |
Mason Creek Nr Caldwell Id
|
46cfs |
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.
Chevally Reservoir
Carter Cr Sf