Pipestem Dam Reservoir Report

Last Updated: December 13, 2025

Pipestem Dam, also known as Pipestem Lake, in Jamestown, North Dakota, is a federal-owned structure managed by the US Army Corps of Engineers.


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Summary

Completed in 1974, the earth dam primarily serves the purpose of flood risk reduction along Pipestem Creek. With a hydraulic height of 99 feet and a structural height of 110 feet, the dam has a storage capacity of 181,650 acre-feet and covers a surface area of 855 acres. Despite its reliability in reducing floods, the dam poses a high hazard potential due to the downstream consequences in Jamestown and Lamoure from potential spillway damage during extreme events.

To mitigate risks, the USACE is actively implementing measures to enhance the dam's safety. A Dam Safety Modification Study conducted in 2020 identified the need for spillway modifications, scheduled to begin in 2023 and conclude by the end of 2026. These modifications aim to make the spillway more resistant to erosion during large water releases, thereby reducing the likelihood of catastrophic flooding in downstream communities. Additionally, the USACE encourages the public to stay informed about flood risks, monitor weather forecasts, and have evacuation plans in place to minimize individual risks during flood events.

Year Completed

1974

Dam Length

4000

River Or Stream

PIPESTEM CREEK

Primary Dam Type

Earth

Surface Area

855

Hydraulic Height

99

Drainage Area

594

Nid Storage

181650

Structural Height

110

Outlet Gates

Uncontrolled - 0

Hazard Potential

High

Foundations

Soil

Nid Height

110
       
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.