Quaker Mills Milldam Reservoir Report

Last Updated: December 5, 2025

Located on the Maquoketa River in Manchester, Iowa, the Quaker Mills Milldam stands as a historical landmark with a primary purpose of recreation.


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Summary

Constructed in 1922, this gravity dam stands at a height of 20 feet and boasts a storage capacity of 1,257 acre-feet. With a surface area of 125 acres and a drainage area of 159 square miles, this dam offers a picturesque setting for water resource and climate enthusiasts to explore.

Managed by the Iowa Department of Natural Resources, the Quaker Mills Milldam is regulated, inspected, and enforced to ensure its structural integrity and safety. Despite its low hazard potential, the dam is assessed to be in satisfactory condition, providing visitors with a safe and enjoyable recreational experience. With a spillway width of 103 feet and uncontrolled spillway type, the dam maintains a moderate risk level but is equipped with risk management measures to mitigate potential hazards.

For those interested in exploring the intersection of water resources and climate change, the Quaker Mills Milldam offers a unique opportunity to witness a historic structure that continues to serve as a vital part of the local ecosystem. With its scenic location on the Maquoketa River and its commitment to safety and maintenance, this dam is a testament to the importance of responsible water management in the face of changing environmental conditions.

Year Completed

1922

Dam Length

200

Dam Height

20

River Or Stream

MAQUOKETA RIVER

Primary Dam Type

Gravity

Surface Area

125

Drainage Area

159

Nid Storage

1257

Hazard Potential

Low

Foundations

Rock, Soil

Nid Height

20
       
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.