Mormon Trail Lake Dam Reservoir Report
Nearby: Cummins Dam Behnken Dam
Last Updated: December 14, 2025
Mormon Trail Lake Dam, located in Mt.
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Summary
Etna, Iowa, is a recreational earth dam completed in 1965 with a height of 46 feet and a length of 928 feet. The dam serves the primary purpose of recreation, providing a surface area of 33 acres for water enthusiasts to enjoy. Owned by the local government and regulated by the Iowa DNR, the dam has a low hazard potential and is in satisfactory condition as of the last assessment in December 2014.
The dam impounds water from the TR-West Fork Nodaway River, creating a reservoir with a normal storage capacity of 394 acre-feet and a maximum storage of 585 acre-feet. With a drainage area of 0.65 square miles, the dam has an uncontrolled spillway with a width of 4 feet. Despite being constructed over five decades ago, Mormon Trail Lake Dam still meets modern regulatory standards for inspection, permitting, and enforcement. With a moderate risk assessment rating of 3, the dam is actively monitored to ensure the safety and security of the surrounding community and environment.
Year Completed |
1965 |
Dam Length |
928 |
Dam Height |
46 |
River Or Stream |
TR-WEST FORK NODAWAY |
Primary Dam Type |
Earth |
Surface Area |
33 |
Drainage Area |
0.65 |
Nid Storage |
585 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
46 |
Seasonal Comparison
Weather Forecast
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.
Mormon Trail Lake Dam