Hubbard Dam Reservoir Report
Nearby: Hiatt Dam Wasteney Dam
Last Updated: January 11, 2026
Hubbard Dam is a privately owned structure located in Diagonal, Iowa, that serves primarily for recreational purposes.
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Summary
Constructed in 1971 by the USDA NRCS, this earth dam stands at a height of 24 feet and spans a length of 416 feet, with a storage capacity of 65 acre-feet. Situated on TR-West Plum Creek, the dam's reservoir covers a surface area of 4.8 acres and has a drainage area of 0.26 square miles. Despite its low hazard potential, the dam is regulated and inspected by the Iowa Department of Natural Resources, ensuring its safety and compliance with state regulations.
With its uncontrolled spillway and soil foundation, Hubbard Dam presents a moderate risk level, as assessed by the authorities. While the dam's condition is currently not rated, it has not undergone any modifications since its completion. The emergency action plan status, including preparedness and risk management measures, remains unclear. The dam's location in Union County, Iowa, under the jurisdiction of the Rock Island District of the US Army Corps of Engineers, is represented by Congresswoman Cindy Axne. Water and climate enthusiasts may find Hubbard Dam to be an interesting case study in recreational dam infrastructure, showcasing the intersection of water resource management and environmental stewardship.
Year Completed |
1971 |
Dam Length |
416 |
Dam Height |
24 |
River Or Stream |
TR-WEST PLUM CREEK |
Primary Dam Type |
Earth |
Surface Area |
4.8 |
Drainage Area |
0.26 |
Nid Storage |
65 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
24 |
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.
Hubbard Dam