Andersen Dam Reservoir Report
Nearby: Erickson Dam Cleveland Dam
Last Updated: December 13, 2025
Andersen Dam, located in Harrison County, Iowa, is a privately owned structure designed by NRCS for grade stabilization purposes.
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Summary
Completed in 2001, this earth dam stands at a height of 27 feet and spans a length of 432 feet, providing a maximum storage capacity of 29 acre-feet. The dam is situated on TR-WILLOW CREEK and is regulated by the Iowa Department of Natural Resources, with state permitting, inspection, and enforcement in place to ensure its safety and functionality.
With a low hazard potential and a moderate risk assessment rating, Andersen Dam serves as a crucial component in managing water resources in the region. The dam's primary purpose of grade stabilization helps control erosion and protect downstream areas from flooding, with an uncontrolled spillway designed to manage excess water flow. Despite not having a current condition assessment, the dam's construction and design meet regulatory standards and contribute to the overall water management efforts in the area.
As a significant infrastructure in the Rock Island District, Andersen Dam plays a vital role in water resource management in Iowa. With its strategic location and design, the dam effectively contributes to flood control and water storage, showcasing the importance of sustainable water infrastructure in mitigating the impacts of climate change. Climate enthusiasts and water resource professionals alike can appreciate the functionality and significance of Andersen Dam in maintaining the ecological balance of the surrounding area.
Year Completed |
2001 |
Dam Length |
432 |
Dam Height |
27 |
River Or Stream |
TR-WILLOW CREEK |
Primary Dam Type |
Earth |
Surface Area |
2.4 |
Drainage Area |
0.14 |
Nid Storage |
29 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
27 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Soldier River At Pisgah
|
112cfs |
Boyer River At Logan
|
417cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Maple River At Mapleton
|
323cfs |
Missouri River At Decatur
|
15500cfs |
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.
Andersen Dam