On October 2, 2025, Maryland Governor Wes Moore announced a new agreement with Constellation Energy to fund and implement operational improvements and environmental projects at the Conowingo Dam.
Valued at more than $340 million and negotiated in partnership with Waterkeepers Chesapeake and Lower Susquehanna Riverkeeper Association, the commitments will meet enforceable water quality standards by mitigating the impacts associated with the dam’s operation.
The agreement clears the way for the re-licensing and continued operation of the dam’s hydroelectric facility on the Susquehanna River, which is the largest source of renewable energy in the state.
The terms of the agreement include operational improvements and upfront and ongoing annual payments:
Water quality and resiliency: $87.6 million for pollution reduction and resiliency initiatives, including shoreline restoration, forest buffers, fish passage projects and planting underwater grasses that produce oxygen, stabilize sediments and provide habitat for countless species.
Trash and debris removal: $77.8 million to strengthen efforts that already clear an average of about 600 tons of debris each year, with innovative approaches like barging for removal.
Aquatic life passage: More than $28 million for fish and eel passage improvements and protections at the dam, helping American shad, river herring, and freshwater mussels rebound while reconnecting habitats across the Susquehanna.
Freshwater mussel restoration: $23.3 million to build and operate a hatchery that will seed the river with mussels, which, like oysters, are natural filters that clean the water and reduce pollution flowing into the Bay.
Dredging: $18.7 million to support additional studies on dredging and related activities.
Invasive species management: $9.4 million to control destructive species like snakeheads and blue catfish, protecting the river’s ecosystem and supporting Maryland’s fishing economy.
Ongoing: Lower Susquehanna Riverkeeper Association and Waterkeepers Chesapeake have an ongoing role in aspects of the implementation of the certification and settlement agreement.
The commitments are contained in a Revised Water Quality Certification issued by the Maryland Department of the Environment and a companion settlement agreement. The department issues certifications pursuant to authority from Section 401 of the Clean Water Act. For a dam, a certification works like a permit and has conditions and requirements for the operation of the dam.
An initial certification was issued in 2018, but legal challenges led to a 2019 waiver of that certification and settlement, requiring the dam owner to invest in improvements valued at $230 million. The terms were dependent on the facility’s receipt of a 50-year federal license, but an appeals court vacated that license in 2022.
To reach the 2025 agreement, the extensive reconsideration process included a public comment period and more than a year of mediation involving the State, Constellation, Lower Susquehanna Riverkeeper Association, and Waterkeepers Chesapeake. A Revised Water Quality Certification will be filed with the federal government for the dam’s license to be renewed.
Once the conditions of the Revised Water Quality Certification are incorporated in the dam’s operating license, Maryland will ensure that the obligations in the Certification are fully and effectively enforced.
For more information on the agreement, visit mde.maryland.gov.
source: Office of Governor Wes Moore
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