Great Stream Commons Upper Reservoir Report

Last Updated: December 9, 2025

Great Stream Commons Upper is a local government-owned dam located in Gregg Township, Pennsylvania, along the TR Susquehanna River.


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Summary

Completed in 2001, this Earth-type dam stands at a height of 17 feet and has a storage capacity of 10.7 acre-feet, serving primarily for flood risk reduction in the area. The dam covers a drainage area of 0.36 square miles and has a surface area of 0.5 acres.

Managed by the Pennsylvania Department of Environmental Protection, Great Stream Commons Upper is regulated, permitted, inspected, and enforced by the state agency. With a significant hazard potential and a moderate risk assessment rating, this dam plays a crucial role in mitigating flood risks in the region. While the condition assessment is not rated, the dam undergoes inspections every two years to ensure its structural integrity and safety measures are up to standard.

In case of emergencies, the dam does not have an Emergency Action Plan in place, but it is vital for water resource and climate enthusiasts to monitor and support risk management measures for Great Stream Commons Upper to safeguard the surrounding communities and the environment from potential hazards.

Year Completed

2001

Dam Length

100

Dam Height

17

River Or Stream

TR SUSQUEHANNA RIVER

Primary Dam Type

Earth

Surface Area

0.5

Drainage Area

0.36

Nid Storage

10.7

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

17
       
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.