Banks Dam Reservoir Report

Last Updated: December 16, 2025

Banks Dam, located in Big Sioux River, Plymouth County, Iowa, is a privately owned structure designed by USDA NRCS and completed in 1967.


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Summary

With a height of 35 feet and a length of 559 feet, this earth dam serves multiple purposes including fire protection, stock, and small fish pond. The dam has a storage capacity of 152 acre-feet, with a normal storage of 50 acre-feet and a surface area of 7.3 acres.

Managed by the Iowa Department of Natural Resources, Banks Dam is regulated, permitted, inspected, and enforced by state authorities. The dam has a low hazard potential and a moderate risk assessment rating. Although the condition assessment is currently not rated, the dam meets regulatory guidelines and has not experienced any significant modifications since its completion. With a controlled spillway type and no outlet gates, Banks Dam ensures the safety and stability of the surrounding area while providing valuable water resources for various uses.

Water resource and climate enthusiasts will appreciate Banks Dam for its role in maintaining water supply, supporting wildlife, and protecting against fire hazards in the region. The dam's strategic location along the 1023 TR-Broken Kettle Creek contributes to flood control and water management efforts in the area. As a vital infrastructure for the community, Banks Dam exemplifies the importance of sustainable water resource management and climate resilience in a changing environment.

Year Completed

1967

Dam Length

559

Dam Height

35

River Or Stream

1023 TR-BROKEN KETTLE CREEK

Primary Dam Type

Earth

Surface Area

7.3

Drainage Area

1.84

Nid Storage

152

Hazard Potential

Low

Foundations

Soil

Nid Height

35
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.