Little Sioux Dam Reservoir Report
Last Updated: January 11, 2026
Located in Harrison County, Iowa, the Little Sioux Dam is a gravity dam built in 1963 on the Little Sioux River.
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Summary
Managed by the local government, this structure serves multiple purposes beyond flood control, storing up to 500 acre-feet of water for various needs. With a height of 7 feet and a length of 200 feet, the dam contributes to the conservation of water resources in the region.
The Army Corps of Engineers designed the Little Sioux Dam, which is regulated by the Iowa Department of Natural Resources. Despite having a low hazard potential, the dam's condition is currently not rated. Its risk assessment is moderate, highlighting the importance of ongoing monitoring and maintenance efforts to ensure the safety and effectiveness of this essential water resource infrastructure. Enthusiasts of water resources and climate will find the Little Sioux Dam an intriguing case study in sustainable water management within the state of Iowa.
Year Completed |
1963 |
Dam Length |
200 |
Dam Height |
7 |
River Or Stream |
LITTLE SIOUX RIVER |
Primary Dam Type |
Gravity |
Surface Area |
143 |
Drainage Area |
4507 |
Nid Storage |
500 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
7 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Soldier River At Pisgah
|
112cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Little Sioux River Near Turin
|
1040cfs |
Missouri River At Decatur
|
14200cfs |
Boyer River At Logan
|
417cfs |
Logan Creek Near Uehling
|
359cfs |
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.
Little Sioux Dam