A Big Dam Problem: Cleaning up Conowingo

The Conowingo Dam, owned by Constellation Energy, is one of the largest non-federal hydroelectric dams in the United States. It is situated in the lower Susquehanna River in Maryland, just south of the Pennsylvania border. On average, the reservoir traps about three million pounds of phosphorus and four billion pounds of sediment annually. Unfortunately, the area behind the wall has lost its ability to trap pollution. During heavy rain events and major storms, some of the pollution scours the dam’s 94 ft high walls and washes downstream. For decades, the dam has protected the Susquehanna river and the Chesapeake Bay from stormwater and agriculture runoff. But its ability to protect wildlife, water quality, and public health is dwindling. So, whose responsibility is it to clean it up?

The National Wildlife Federation hosts the Choose Clean Water Coalition and our membership of over 285 nonprofit organizations. Together, we have been working for more than 14 years to protect the rivers and streams that flow into the Chesapeake Bay watershed. Supplying more than 50 percent of all the Bay’s freshwater, we must protect the Susquehanna River at all costs. Not only is it a critical resource for the fish and wildlife habitat that inhabit the river, it is vital for thousands of people who recreate and relay on the river as a major source of clean water. For decades, Constellation and its corporate predecessors have failed to keep up with the proper maintenance needed to operate the dam, while exploiting a public resource to pad their bottom line. It is their responsibility to clean it up.

In 2018, Constellation’s 50-year license to operate the dam expired. Under Section 401 of the Clean Water Act, a federal agency cannot issue a license to operate that may result in any water discharge unless a water quality certification is issued or waived by the relevant state. Given Conowingo’s pollution challenges, Maryland issued a certificate that required the dam’s operator to either dredge the reservoir or pay billions in compensation for the nutrients flowing out. The power company sued and challenged those requirements in courts a year later. Ultimately, Maryland reached a backdoor settlement with Constellation that required the company to pay the state about $200 million over the next half century to address pollution. Then the Federal Energy Regulatory Commission (FERC) approved a new 50-year license and was met with challenges from the Bay community.

In 2022, the Coalition along with our members Chesapeake Bay Foundation, Lower Susquehanna Riverkeeper, ShoreRivers, and Waterkeepers Chesapeake, issued a challenge to the ruling that vacated FERC’s 50-year license for Conowingo Dam. We argued that the license was unwarranted due to the failure to address systemic water pollution issues associated with the dam’s operations. After years of petitioning, phone calls, and meetings with elected officials, the D.C. Circuit Court of Appeals issued a ruling in our favor of vacating FERC’s 50-year license for Constellation. The appeals court ruled that FERC should not have allowed Maryland to backtrack on its earlier conditions of what was needed to ensure water quality. It ordered the commission to reconsider its decision and either restart the entire process, making Constellation apply for a license all over again, or accept Maryland’s original water quality certification and greater conditions on the company’s continued operation of the dam. 

While we celebrate this victory, we will continue to work with Governor Moore’s Administration to ensure we reach a resolution that promotes the restoration and protection of the Chesapeake Bay while creating outcomes that implement effective and equitable clean water policies. In the Coalition’s recently published LTE’s “At Conowingo, a chance for a more environmentally responsibility agreement” and “Conowingo Dam must be operated responsibly” we recognize that this fight is not over. Stay engaged with our work by visiting our website at www.choosecleanwater.org.