Anderson-Lower (Malheur) Reservoir Report
Last Updated: December 14, 2025
Anderson-Lower (Malheur) is a private dam located in Nyssa, Oregon, along Crooked Creek.
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Summary
Built in 1917, this earth dam stands at a height of 34 feet and has a storage capacity of 2990 acre-feet, primarily used for irrigation purposes. The dam's structure spans 203 feet in length, with a maximum discharge rate of 343.6 cubic feet per second.
Despite being classified as having a low hazard potential, Anderson-Lower (Malheur) is regulated by the Oregon Water Resources Department and undergoes regular state inspections and enforcement measures. The dam features a Needle outlet gate and is situated in a drainage area of 78 square miles. With a surface area of 336 acres, this dam plays a crucial role in water resource management and agricultural activities in the region.
The dam's condition is currently listed as "Not Rated," with the last inspection conducted in March 2020. While no emergency action plan (EAP) or risk assessment information is available, Anderson-Lower (Malheur) continues to provide essential water storage and distribution services for the surrounding area. As climate change impacts water resources, the maintenance and monitoring of dams like Anderson-Lower (Malheur) will be crucial for sustainable water management in the future.
Year Completed |
1917 |
Dam Length |
203 |
Dam Height |
34 |
River Or Stream |
CROOKED CREEK |
Primary Dam Type |
Earth |
Surface Area |
336 |
Hydraulic Height |
30 |
Drainage Area |
78 |
Nid Storage |
2990 |
Structural Height |
34 |
Outlet Gates |
Needle |
Hazard Potential |
Low |
Nid Height |
34 |
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.
Anderson-Lower (Malheur)