Jass Dam Reservoir Report
Nearby: Massey Dam Acheson Dam
Last Updated: December 10, 2025
Jass Dam, located in Decatur County, Iowa, was completed in 1979 and is owned by a private entity.
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Summary
The dam, designed by the USDA NRCS, serves multiple purposes including fire protection, stock, and small fish pond management. With a height of 26 feet and a length of 490 feet, the dam has a storage capacity of 76 acre-feet and covers a surface area of 5.7 acres.
The primary source agency for Jass Dam is the Iowa Department of Natural Resources, which regulates and inspects the dam to ensure its safety and compliance with state standards. The dam is situated on Steele Creek and is classified as an earth dam with a soil foundation. Despite its low hazard potential, the dam has a moderate risk rating of 3, prompting the need for risk management measures to be implemented.
The dam's spillway is uncontrolled, and it does not have outlet gates or associated structures. While the condition assessment of Jass Dam is currently not rated, its risk assessment indicates a moderate level of risk. As a popular water resource and climate enthusiast destination, Jass Dam presents an opportunity for further exploration and study in the realm of sustainable water management practices and climate resilience efforts.
Year Completed |
1979 |
Dam Length |
490 |
Dam Height |
26 |
River Or Stream |
TR-STEELE CREEK |
Primary Dam Type |
Earth |
Surface Area |
5.7 |
Drainage Area |
0.1 |
Nid Storage |
76 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
26 |
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.
Jass Dam