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Conowingo Hydroelectric Generating Station

Conowingo Hydroelectric Generating Station

Conowingo Hydroelectric Generating Station is a run-of-the-river hydroelectric power plant owned and operated by Exelon Power, a business unit of Exelon Generation.

Located on the Susquehanna River in northern Maryland, Conowingo has been providing electricity to the regional system since 1928. When constructed from 1926 to 1928, Conowingo was the largest power plant ever built and had the largest turbines and generators to date. When the Conowingo Dam was completed in 1928, producing 252 megawatts (MW), it became the second largest hydroelectric project in the United States, behind Niagara Falls.

The original plant had 7 turbines and, in 1964, 4 more turbines were added. The water flow of the Susquehanna River provides the fuel for the 11 current turbine generators, producing 500 MW of electricity.  Because water is used to turn the turbines, Conowingo can be used to “jump start” the electric distribution system in the event of a system failure of the PJM connection.


Conowingo has a license issued by the Federal Energy Regulatory Commission (FERC)  that expires September 1, 2014. Exelon wishes to preserve this virtually emissions-free generating capacity and its electrical output, while enhancing both the environmental integrity and local community relationships.

Typically, a FERC license is issued for a period from 30 to 50 years.  Exelon filed an application to relicense Conowingo with FERC in August 2012.  Learn more about Conowingo relicensing efforts.

Supporting the Local Economy

Exelon Generation spends more than $40 million annually to operate and maintain both Conowingo and Muddy Run and pays nearly $5 million in property taxes annually.  The plants have a shared workforce of over 60 Exelon employees.

Emergency Planning

All Exelon facilities employ sophisticated emergency response plans to protect public health and safety.  These plans are reviewed and approved by state governments and regulatory agencies.  The emergency planning includes coordination with local counties, municipalities and school districts.

  • "The new fishing wharf at Conowingo demonstrates Exelon’s commitment to the community. The project preserves our goals of national security while also providing for great fishing for our local folks who love fishing the Susquehanna."
  • - Maryland State Senator Barry Glassman

Community Involvement

Conowingo aims to be a good neighbor and is very active in the local community.

  • Sponsorship.  The power plant sponsors several community events including the Lower Susquehanna Heritage Greenway’s Riversweep and Port Deposit’s annual Rockfish tournament.
  • Charitable Giving & Volunteering.   Conowingo and its employees give generously to the community through a variety of charitable activities including the local United Way chapters and the Boys and Girls Clubs of Cecil and Harford Counties.
  • Recreation.  In 2009, Exelon invested $4.5 million in a fish wharf at the Conowingo dam that allows visitors access to the river for fishing, bird-watching, picnics and photography.  About 4 miles upstream of the Chesapeake Bay, the 14-mile-long Conowingo Pond behind the dam and the tailrace area provide numerous public recreational facilities and activities.

Environmental Impact

Since 1972, Conowingo Dam has been vital to returning American shad to the upper Susquehanna River. A $12 million fish lift was completed in the early 1990s and has restored more than 1 million shad.

2015 Wildlife Photo Contest
Entry Form and Rules PDF

Vice President, Mid-Atlantic Region, Exelon Power: Bill Swahl

General Manager: Archie Gleason

2569 Shures Landing Road
Darlington, Maryland

  • Number of units: 11 turbines
  • Capacity: 572 MW