Arnold-Armstrong Subwtrshd Sta 171+55 Reservoir Report
Last Updated: December 14, 2025
Arnold-Armstrong Subwtrshd Sta 171+55 is a dam located in Monona, Iowa, owned by the local government and regulated by the Iowa Department of Natural Resources.
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Summary
Constructed in 1963 by the USDA NRCS, this earth dam serves multiple purposes including fire protection, stock, small fish pond, and flood risk reduction. Spanning 314 feet in length and standing at a height of 36 feet, the dam has a storage capacity of 104 acre-feet with a normal storage level of 65 acre-feet.
Situated on Dutch Creek, this dam has a low hazard potential and has not been rated for its condition assessment. With a drainage area of 2.62 square miles, the dam covers a surface area of 5.3 acres and has an uncontrolled spillway type. Despite the moderate risk assessment, specific risk management measures and inundation maps have not been prepared for this structure. Overall, Arnold-Armstrong Subwtrshd Sta 171+55 plays a crucial role in water resource management in the region, providing essential services for both the community and the environment.
Year Completed |
1963 |
Dam Length |
314 |
Dam Height |
36 |
River Or Stream |
DUTCH CREEK |
Primary Dam Type |
Earth |
Surface Area |
5.3 |
Drainage Area |
2.62 |
Nid Storage |
104 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
36 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Maple River At Mapleton
|
323cfs |
West Fork Ditch At Hornick
|
80cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Missouri River At Decatur
|
15500cfs |
Soldier River At Pisgah
|
112cfs |
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.
Arnold-Armstrong Subwtrshd Sta 171+55