Summary
With a primary purpose of navigation, the dam also serves fish and wildlife, hydroelectric, and recreational purposes. It features a single lock measuring 674 feet in length and 86 feet in width, allowing for the passage of vessels along the river.
The dam has a structural height of 228 feet and a hydraulic height of 100 feet, with a storage capacity of 485,000 acre-feet and a surface area of 8,900 acres. Managed by the US Army Corps of Engineers, the dam is regularly inspected and monitored for safety, with emergency action plans in place to address any potential risks. The risk management measures include ongoing maintenance, risk assessment, and collaboration with local emergency managers to ensure the safety and integrity of the dam.
Despite the high hazard potential associated with the dam, the US Army Corps of Engineers works diligently to mitigate flood risks and ensure the proper functioning of the structure. With a focus on proactive risk management and public awareness, Lower Granite Lock and Dam plays a crucial role in water resource management and climate resilience efforts in the region.
Year Completed |
1975 |
Dam Length |
3200 |
River Or Stream |
SNAKE RIVER |
Primary Dam Type |
Concrete |
Surface Area |
8900 |
Length Of Locks |
674 |
Hydraulic Height |
100 |
Drainage Area |
103200 |
Nid Storage |
485000 |
Structural Height |
228 |
Hazard Potential |
High |
Nid Height |
228 |
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.
Lower Granite Lock And Dam