Mcnary Lock And Dam - Richland Levee 4a Reservoir Report
Last Updated: December 14, 2025
Mcnary Lock and Dam, located on the Columbia River in Oregon, serves as a crucial flood risk reduction structure with a primary purpose of mitigating potential flooding in the area.
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Summary
Built in 1952 by the US Army Corps of Engineers, this earth dam stands 30 feet high and is one of 12 associated structures in the vicinity. The dam does not eliminate all flood risks, but rather manages water levels through controlled releases to prevent overwhelming the structure.
USACE actively monitors and manages the risks associated with the dam by prioritizing maintenance activities, engaging with emergency managers, and updating emergency action plans regularly. The agency works closely with local authorities to ensure the community is prepared for any potential dam-related emergencies, emphasizing the importance of public awareness and readiness. Despite its high hazard potential, Mcnary Lock and Dam remains a critical resource for flood protection in the region, with ongoing efforts to enhance risk management practices and ensure the dam's structural integrity.
As water resource and climate enthusiasts, understanding the intricate balance of managing flood risks at Mcnary Lock and Dam underscores the importance of proactive measures to protect communities and infrastructure from potential water-related disasters. The US Army Corps of Engineers' diligent efforts to monitor, maintain, and communicate with stakeholders highlight the commitment to safeguarding the area from flood threats and ensuring the long-term functionality of this essential earth dam structure on the Columbia River.
Year Completed |
1952 |
Dam Height |
30 |
River Or Stream |
COLUMBIA |
Primary Dam Type |
Earth |
Hazard Potential |
High |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Yakima River At Kiona
|
27000cfs |
Umatilla River Near Umatilla
|
713cfs |
Walla Walla River Near Touchet
|
1330cfs |
Yakima River At Mabton
|
32100cfs |
Columbia River Below Priest Rapids Dam
|
123000cfs |
Granger Drain At Granger
|
13cfs |
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.
Mcnary Lock And Dam - Richland Levee 4a
Columbia Park Trail 1455, Richland