Tom King Subwatershed Site 6290 Reservoir Report
Last Updated: December 14, 2025
Tom King Subwatershed Site 6290 is a local government-owned dam located in Monona, Iowa, near the Missouri River.
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Summary
Built in 1956 by the USDA NRCS, this earth dam serves multiple purposes including fire protection, stock watering, and small fish pond creation, as well as flood risk reduction. With a dam height of 26 feet and a storage capacity of 110 acre-feet, the site covers a surface area of 2 acres and drains an area of 1.17 square miles.
Managed by the Iowa DNR, the dam has a low hazard potential and a moderate risk assessment. While the condition of the dam is currently not rated, it is regularly inspected and meets state regulatory requirements for permitting, inspection, and enforcement. Located in the TR- W. Fork Little Sioux River watershed, the dam plays a crucial role in managing water resources and protecting the surrounding area from potential flooding events. With its strategic location and multiple functions, Tom King Subwatershed Site 6290 is a key asset in the region's water resource and climate resilience efforts.
Year Completed |
1956 |
Dam Height |
26 |
River Or Stream |
TR- W. FORK LITTLE SIOUX RIVER |
Primary Dam Type |
Earth |
Surface Area |
2 |
Drainage Area |
1.17 |
Nid Storage |
110 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
26 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
West Fork Ditch At Hornick
|
80cfs |
Maple River At Mapleton
|
323cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Little Sioux River Near Turin
|
1040cfs |
Missouri River At Decatur
|
14900cfs |
Little Sioux River At Correctionville
|
327cfs |
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.
Tom King Subwatershed Site 6290