Conowing flood gates open. Photo by david Turnbull | Courtesy of www.cbf.org
Maryland 2025 - In a long-awaited win for water quality, Governor Wes Moore announced a $341 million settlement with Constellation Energy, the owner of Conowingo Dam. The settlement will support water quality and debris removal in the Susquehanna River and Chesapeake Bay.
For decades, Conowingo Dam has inadequately managed pollution accumulating from the Susquehanna River, which is the source of about half of the Chesapeake Bay's fresh water. The dam alters when and how pollution reaches the Bay. However, the reservoir that traps sediment and nutrient pollution has been at capacity for years. Large storms, which are getting more severe and frequent from climate change, cause overflows that scour pollutants from behind the dam right into the Bay, fueling algal blooms and threatening marine life.
After immense public concern and multiple legal challenges, a $200 million settlement was reached in 2019 between the dam’s operator and Maryland Department of the Environment (MDE) in which the state attempted to waive the water quality certification for the dam. Environmental groups and concerned citizens believed the agreement was insufficient and did little to prevent pollution, since it allowed Constellation to avoid most water quality improvements required by the state.
In response to these concerns, in 2021, Chesapeake Bay Foundation (CBF), Waterkeepers Chesapeake, Lower Susquehanna Riverkeeper, and ShoreRivers challenged a 50-year permit for the dam to operate. The groups believed Maryland could not waive the dam’s water quality certification, and that Constellation’s license should require them to mitigate the water quality impacts of the dam. The U.S. Court of Appeals for the D.C. Circuit agreed, and the Waterkeepers, Riverkeeper, MDE, and Constellation returned to the negotiating table.
The updated settlement will require tangible investments in Susquehanna River water quality such as restoring mussel populations via a new hatchery, combatting invasive species, improving fish passage, and studying the viability of dredging sediment trapped by the dam.
CBF President & CEO Hilary Harp Falk issued the following statement:
“This is a keystone moment for the Susquehanna River and Chesapeake Bay. Accountability is what got us here and will be key to carrying out the terms of the settlement and ensuring its tangible water quality benefits. This was a decades long fight, and there’s still work to be done.
“Pennsylvania holds a key role in a healthier Bay. Their continued leadership alongside Governor Moore will be crucial. Pollution doesn’t respect state lines. That’s why everyone must work together to see real progress.
“We are thankful to the Waterkeepers, Riverkeeper, and the Moore-Miller Administration for their leadership in Bay clean up and for holding Constellation accountable with this settlement. Those who rely on a clean Bay for their work, enjoyment, and health will be better off because of it.”
