There are no reservoirs (dams) on the mainstem Delaware River, but several reservoirs are located on tributaries to the Delaware River. They play an important role in drinking water supply and flow management.

Key Reservoirs:

• New York City Delaware Basin Reservoirs
  
  
• U.S. Army Corps of Engineers Reservoirs

Major Reservoirs in the Delaware River Basin 

View Map as pdf

Reservoirs in the DRB are used for the following purposes (some are multi-purpose)

• Water Supply
  
  
• Hydroelectric Power
  
  
• Flood control 
  
  
• Recreation

See Also

• DRB Flow Management
  
  
• DRBC Drought Operations

Reservoir Storage Studies

• F.E. Walter Reservoir Re-Evaluation Study (ongoing study by the USACE; DRBC is a non-federal co-sponsor of this study)
  
  
• Evaluation of Additional Storage in the Delaware River Basin (DRBC study initiated in 2021; final report issued April 2023)

New York City Delaware River Basin Reservoirs (owned & operated by NYCDEP)

• Cannonsville Reservoir - located on the West Branch Delaware River
  
  
• Pepacton Reservoir - located on the East Branch Delaware River
  
  
• Neversink Reservoir - located on the Neversink River

Reservoir Levels:

• Daily from the DRBC via the Hydrologic Conditions in the DRB Dashboard
  
  
• Weekly from the DRBC at NYC Delaware River Basin Reservoir Storage Info
  
  
• Current Info from NYC at Reservoir Levels from the NYC Dept. of Environmental Protection

NYC DRB Reservoirs, Drinking Water & Flow Management

• Reservoirs located in the headwaters to the Delaware River in New York State
  
  
• Water from these reservoirs is transferred to New York City through the Delaware Aqueduct and via the Roundout Reservoir
  
  
• Water is used for public water supply, serving roughly 1/2 of NYC and communities along the route
  
  
• Through the Delaware River Master (a USGS position), releases from these reservoirs are made to meet the Montague, N.J. flow target of 1,750 cubic feet per second (cfs)
  
  
• Storage levels in these reservoirs drive the DRBC's basin-wide drought management plan
  
  
• DRBC works closely with the River Master and others to monitor storage in these three reservoirs

Delaware Aqueduct to Shut Down for Repairs

The NYC Dept. of Environmental Protection announced a planned shutdown of the Delaware Aqueduct, which started in October 2024. However, due to drought conditions, the project was paused in Nov. 2024. Stay tuned for 2025 details.

• Learn more about the shutdown project

U.S. Army Corps of Engineers Reservoirs

• F. E. Walter Reservoir
  
  
• Blue Marsh Reservoir
  
  
• Beltzville Reservoir
  
  
• Prompton & Jadwin Dams

Learn more:

• U.S. Army Corps of Engineers: Philadelphia District (main website)
  
  
• U.S. Army Corps of Engineers: Philadelphia District River Basins (hydrologic info)

Army Corps Reservoirs & Flow Management

• DRBC owns water supply storage in two Corps' reservoirs, Beltzville and Blue Marsh, which are located in the Lehigh and Schuylkill sub-basins respectively
  
  
• Storage is utilized to meet the Trenton, N.J. flow target of 3,000 cfs
  
  
• Storage levels in these reservoirs drive the DRBC's lower basin drought operating plan

Merrill Creek Reservoir

• Merrill Creek Reservoir was built by a consortium of power companies in order to provide water releases in times of drought to make up for their consumptive use.
  

Marsh Creek Reservoir

• Storage in the Marsh Creek Reservoir, located in Chester County, Pa., is used to support in-stream flow management in the Brandywine Creek.
  

Additional Reservoirs Used in Drought Emergency

In times of drought emergency, (view map as pdf), DRBC can call for an additional 69 billion gallons (BG) of water for flow augmentation from several other Basin reservoirs:

• Mongaup System (15 BG)
  
  
• Lake Wallenpaupack (30 BG)
  
  
• F.E. Walter Reservoir (11 BG)
  
  
• Lake Nockamixon (13 BG)

• View DRB Water Management schematic (pdf)
  
  
• Hydrologic Reports
  
  
• Salt Front Location
  
  
• DRBC Water Supply/Planning Program