General Edgar Jadwin Dam, PA
Upgrading flood control infrastructure with geosynthetics
AEG, a SOCOTEC Company, provided surveying and geotechnical support for a Dam Safety Modification project at the General Edgar Jadwin Dam, a critical flood control structure serving Wayne County, Pennsylvania.
Key Information
Project Name: General Edgar Jadwin Dam
Client: Department of Defense
Location: Wayne County, PA
Services Provided: Surveying and Geotechnical Services
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The Challenge
Maintaining a Decades-Old Flood Control Dam Against Seepage and Long-Term Deterioration
The General Edgar Jadwin Dam was constructed in 1959 by the U.S. Army Corps of Engineers on Dyberry Creek, approximately three miles upstream of Honesdale, Pennsylvania. Since its completion, the dam has prevented millions of dollars in flood damage and serves as a critical component of regional flood risk management.
As a dry dam, meaning it maintains no permanent pool of water, the structure is uniquely designed for flood control operations. It provides up to 24,500 acre-feet of storage to the spillway crest and controls a watershed of 64.5 square miles.
After more than six decades of service, the dam required a Dam Safety Modification to address seepage concerns and reinforce the long-term stability of its upstream slope and crest. The project called for the installation of a geosynthetic liner system, combined with excavation, riprap replacement, and new monitoring infrastructure, all requiring precise survey and geotechnical support.
Key challenges included:
- Reducing seepage through the upstream slope and crest of the dam
- Enhancing long-term structural stability of a dam in continuous operation since 1959
- Installing a complex geosynthetic liner system comprising geomembrane, geotextile, geogrid, and coarse aggregates
- Excavating and replacing existing riprap while maintaining dam integrity
- Establishing accurate baseline survey conditions across disturbed areas for design and construction documentation
- Installing piezometers to enable ongoing monitoring of subsurface water movement
The Solution
Surveying and Geotechnical Services for Dam Safety Modification
AEG, a SOCOTEC Company, delivered a comprehensive range of surveying and geotechnical services to support the 2023 Dam Safety Modification project at the Jadwin Dam.
Existing Conditions Survey:
- Conducted a final existing conditions survey using a combination of scanning, GPS, and conventional survey methods
- Captured detailed topography across all disturbed areas of the dam to support design and construction documentation
Piezometer and Monitoring Infrastructure Survey:
- Provided detailed survey data for piezometer wells and USGS concrete slab locations nearing project completion
- Collected northing, easting, and elevation data for multiple well points to support accurate monitoring and documentation
- Recorded inner top-of-casing and stick-up elevations for all piezometer installations
Geosynthetic Liner System Support:
- Provided geotechnical support for the installation of the geosynthetic liner system on the upstream slope and crest of the dam
- Supported design and construction of the liner system comprising geomembrane, geotextile, geogrid, and coarse aggregates
- Provided survey documentation for excavation and replacement of existing riprap and installation of new riprap
AEG, a SOCOTEC Company, delivered a comprehensive range of surveying and geotechnical services to support the 2023 Dam Safety Modification project at the Jadwin Dam.
Existing Conditions Survey:
- Conducted a final existing conditions survey using a combination of scanning, GPS, and conventional survey methods
- Captured detailed topography across all disturbed areas of the dam to support design and construction documentation
Piezometer and Monitoring Infrastructure Survey:
- Provided detailed survey data for piezometer wells and USGS concrete slab locations nearing project completion
- Collected northing, easting, and elevation data for multiple well points to support accurate monitoring and documentation
- Recorded inner top-of-casing and stick-up elevations for all piezometer installations
Geosynthetic Liner System Support:
- Provided geotechnical support for the installation of the geosynthetic liner system on the upstream slope and crest of the dam
- Supported design and construction of the liner system comprising geomembrane, geotextile, geogrid, and coarse aggregates
- Provided survey documentation for excavation and replacement of existing riprap and installation of new riprap
The Results
Critical Infrastructure Upgraded for Decades of Continued Flood Protection
Through expert surveying and geotechnical services, AEG, a SOCOTEC Company, helped ensure the successful implementation of this critical infrastructure upgrade, enhancing the dam's performance and resilience for decades to come.
Key Outcomes:
- Geosynthetic liner system successfully installed on the upstream slope and crest of the dam in 2023, reducing seepage and reinforcing long-term stability
- Accurate existing conditions survey delivered across all disturbed areas using scanning, GPS, and conventional methods
- Piezometer monitoring infrastructure fully documented with precise northing, easting, and elevation data to support ongoing subsurface water movement tracking
- Dam's flood control capacity preserved — up to 24,500 acre-feet of storage and control of 64.5 square miles of watershed — with enhanced structural integrity
- Continued protection of the Honesdale region from flood damage, building on more than six decades of uninterrupted flood risk management
