Pattison Dam Reservoir Report

Last Updated: December 5, 2025

Pattison Dam, located in Guttenberg, Iowa, is a privately owned structure that has been regulated and permitted by the Iowa Department of Natural Resources.


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Summary

Completed in 2008, this earth-type dam stands at a height of 68 feet and spans a length of 558 feet. With a normal storage capacity of 160 acre-feet, the dam serves the primary purpose of "Other," indicating its role in managing water resources for various uses.

The dam's spillway type is classified as "Uncontrolled," with a spillway width of 2 feet. Despite its low hazard potential and satisfactory condition assessment as of 2009, Pattison Dam is subject to moderate risk due to its location along the TR-Mississippi River. The risk management measures for the dam are not specified, suggesting the need for ongoing monitoring and maintenance to ensure its continued safety and functionality in the face of changing environmental conditions.

For water resource and climate enthusiasts, Pattison Dam offers a fascinating case study in dam construction, regulation, and risk assessment. As a key infrastructure element within the St. Paul District of the US Army Corps of Engineers, the dam plays a crucial role in managing water flow and storage along the Mississippi River. Its design by Michael Ryan of Howard R. Green Co. highlights the expertise and collaboration required to create sustainable water management solutions in a changing climate.

Year Completed

2008

Dam Length

558

Dam Height

68

River Or Stream

TR- MISSISSIPPI RIVER

Primary Dam Type

Earth

Surface Area

8.8

Drainage Area

0.03

Nid Storage

208

Hazard Potential

Low

Foundations

Rock, Soil

Nid Height

68
       
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.