Constellation Energy has agreed to invest over $340 million to improve water quality at Maryland’s Conowingo Dam. This dam is located on the Susquehanna River, which eventually flows into the Chesapeake Bay, the largest estuary in the United States. The announcement was made last week and paves the way for renewing the dam’s operating license.
The Conowingo Dam is Maryland’s biggest source of renewable energy with its hydroelectric facility. The funding will address ongoing pollution problems linked to sediment buildup trapped behind the dam, which can wash downstream and harm the bay’s ecosystem.
The deal resolves a long-standing disagreement over who should pay for fixing the pollution caused by the dam’s sediment. Back in 2018, the Maryland Department of the Environment gave initial approval for the dam’s certification, but legal challenges delayed the process. By 2019, settlement terms required Constellation to spend $230 million on environmental upgrades tied to a new 50-year federal license. That license faced further legal challenges and was temporarily overturned in 2022 following pressure from environmental groups.
The new agreement came after talks involving Constellation Energy and local water advocacy groups, including Waterkeepers Chesapeake and the Lower Susquehanna Riverkeeper Association. It spells out enforceable standards for water quality while allowing the dam to keep operating.
About $88 million of the funds will go toward pollution reduction and resilience projects such as shoreline restoration, planting forest buffers, improving fish passages, and adding underwater grasses that help oxygenate the water and provide habitat. Another $78 million will help remove trash and debris, supplementing existing efforts that clear roughly 600 tons each year.
Additional investments will support a freshwater mussel hatchery, control invasive species, and explore the possibility of dredging sediment from the dam to further improve water health. An updated water quality certification will be filed to renew the dam’s federal license under these new terms.
Maryland Governor Wes Moore highlighted the importance of this deal in protecting the Chesapeake Bay while supporting clean energy. Local advocates praised the effort as the conclusion of many years of work to secure proper protections for the river and bay.
This agreement marks a significant step forward for environmental health in the region and ensures that one of Maryland’s major sources of renewable energy can continue operating with stronger safeguards for the water downstream.