Maryland Gov. Larry Hogan is mobilizing a massive statewide response to stave off a potential disaster from a dam breach that already has local officials organizing voluntary evacuations.
Weeklong rainfall forced the large Conowingo Dam on Thursday to open multiple spill gates, a warning sign that the dam is having difficulties holding back the water of the Susquehanna River.
“Maryland state agencies are actively engaged and working around the clock to provide any support needed to Port Deposit and the areas surrounding the Conowingo Dam,” said the Republican governor. “I urge all local residents to put safety first and heed all warnings from local officials.”
His office explained that significant amounts of rain and water flow in the Susquehanna River prompted the response. Hogan has “directed state agencies” to coordinate a massive state-wide mobilization that includes the town of Port Deposit beginning voluntary evacuations.
Wayne Tome, Sr., the mayor of Port Deposit, has called for a voluntary evacuation, Hogan’s office pointed out. Port Deposit officials are making shuttles available to move people who do not have their own vehicles, and have converted an elementary school into a staging point to coordinate the effort. Port Deposit is the closest town to the dam, which is two hours north of Washington.
The state is preparing for a possible water contamination event from flooding resulting from the dam not being able to control the surging rain amounts.
The Maryland Department of Environment will be enforcing Hogan’s new clean water rules that require the dam operator to reduce sediment and debris behind the dam to prevent risks to public safety and environmental health, while also keeping the Chesapeake Bay’s environmental cleanup progress on track, according to the governor’s office.
“The MDE certification is part of the Hogan Administration’s comprehensive and holistic strategy to reduce nutrient and sediment pollution, including trash and debris, behind the dam and up the river into Pennsylvania and New York, to protect Maryland waters, including the Chesapeake Bay,” his office said.
The Maryland Department of Natural Resources is beginning water sampling on Thursday and through the weekend to monitor the Chesapeake Bay for nutrients, sediment, and turbidity, according to Hogan’s office. “Excess nutrients and sediments can degrade water quality, cause algal blooms, increase hypoxia levels and inhibit submerged aquatic vegetation growth,” a statement said.
The Maryland Natural Resources Police are also coordinating emergency response efforts with the energy company Exelon and the Maryland Emergency Management Agency, along with local officials. Hogan’s office said it has mobilized a fleet of all-terrain vehicles and marine vessels to assist in a variety of emergency situations, including localized flooding.

