Lyman Run Reservoir Report

Last Updated: December 6, 2025

Lyman Run, located in Potter County, Pennsylvania, is a state-regulated recreational dam completed in 2007.


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Summary

Standing at a height of 52.6 feet and with a storage capacity of 1350 acre-feet, this earth dam serves primarily for recreational purposes in the West Branch Township. The dam, with a spillway width of 896 feet and a surface area of 40 acres, has a high hazard potential but is currently assessed to be in satisfactory condition.

Managed by the Pennsylvania Department of Environmental Protection, Lyman Run offers a serene setting for outdoor enthusiasts to enjoy activities such as fishing, boating, and hiking. The dam, with its uncontrolled spillway, plays a crucial role in regulating the downstream flow of Lyman Run, a tributary in the Buffalo District. Despite its moderate risk assessment, the dam has undergone regular inspections and meets state regulatory guidelines for operation and maintenance. With its picturesque surroundings and important recreational function, Lyman Run serves as a vital water resource and climate feature for the local community and visitors alike.

Years Modified

2007 - Other

Year Completed

2007

Dam Length

1000

Dam Height

52.6

River Or Stream

LYMAN RUN

Primary Dam Type

Earth

Surface Area

40

Drainage Area

18.4

Nid Storage

1350

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

53
       
Seasonal Comparison

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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.