Greene Dreher (Pa-447) Reservoir Report

Last Updated: December 7, 2025

Greene Dreher (Pa-447) is a significant local government-owned earth dam located in Dreher Township, Wayne County, Pennsylvania.


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Summary

Constructed in 1961 by the USDA NRCS, this dam spans 1000 feet in length and stands at a height of 20 feet, serving primarily for flood risk reduction along Manny Run. With a storage capacity of 196 acre-feet and a drainage area of 0.37 square miles, Greene Dreher plays a crucial role in mitigating flood hazards in the region.

Managed and regulated by the Pennsylvania Department of Environmental Protection, Greene Dreher has been classified as having a high hazard potential but is currently assessed to be in fair condition. The dam's inspection frequency is set at once per year, with the last assessment conducted in November 2020. While specific risk management measures and emergency action plans are not explicitly outlined for this structure, its operational oversight and state-mandated monitoring ensure ongoing safety and preparedness measures are in place for any potential emergencies.

Overall, Greene Dreher (Pa-447) stands as a key infrastructure asset in Wayne County, Pennsylvania, offering essential flood protection and water resource management capabilities for the local community. As climate change continues to impact weather patterns and intensify precipitation events, the proper maintenance and regulation of dams like Greene Dreher become increasingly vital in safeguarding against flooding risks and ensuring the resilience of water resources in the region.

Year Completed

1961

Dam Length

1000

Dam Height

20

River Or Stream

MANNY RUN

Primary Dam Type

Earth

Surface Area

4

Drainage Area

0.37

Nid Storage

196

Hazard Potential

High

Foundations

Unlisted/Unknown

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.