Peterson Dam Reservoir Report
Nearby: Lazy K Dam Thomson Dam
Last Updated: December 14, 2025
Peterson Dam, located in Defiance, Iowa, is a privately owned structure designed by NRCS to serve multiple purposes including fire protection, stock, and small fish pond.
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Summary
Completed in 1993, this earth dam stands at a height of 19 feet and spans 417 feet in length, with a storage capacity of 52 acre-feet. Situated on the TR-W.FK. WEST NISHNABOTNA R. river, the dam covers a surface area of 5.5 acres and has a drainage area of 0.15 square miles.
With a low hazard potential and a moderate risk assessment rating of 3, Peterson Dam is state regulated and permitted by the Iowa Department of Natural Resources. Despite being uncontrolled, the dam's spillway type ensures efficient water management. While the dam's condition assessment is currently not rated, it undergoes regular state inspections, enforcement, and permitting to uphold safety standards. Overall, Peterson Dam serves as a vital resource for water storage and management in the region, contributing to the conservation and sustainability of water resources amidst changing climate conditions.
Year Completed |
1993 |
Dam Length |
417 |
Dam Height |
19 |
River Or Stream |
TR-W.FK. WEST NISHNABOTNA R. |
Primary Dam Type |
Earth |
Surface Area |
5.5 |
Drainage Area |
0.15 |
Nid Storage |
52 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
19 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Boyer River At Logan
|
417cfs |
West Nishnabotna River At Hancock
|
154cfs |
Soldier River At Pisgah
|
112cfs |
Maple River At Mapleton
|
323cfs |
East Nishnabotna River Near Atlantic
|
143cfs |
North Raccoon River Near Sac City
|
312cfs |
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.
Peterson Dam