In the face of more frequent and intense rainfall, dam failures are becoming the norm. What can be done with the underfunded relics?
Annapolis, Md.—DJ Buckley spent most of his afternoon on Aug. 3 picking up branches and debris out of the Annapolis Harbor.
After the Conowingo Dam opened 17 floodgates due to rising water levels, built-up debris came washing through into the harbor.
"I can't remember a time when I've seen that much in here," Buckley said.
The debris in the harbor led Maryland Comptroller Peter Franchot to call out Pennsylvania for the amount of garbage and branches in the Susquehanna River, which flows through the Conowingo Dam and into the harbor.
The incident leads to more questions about dams in the U.S. While the Conowingo opening up its gates does not constitute as a failure, as storms become more intense due to the changing climate, there will be more overtopping at deficient dams, Mark Ogden, technical specialist with the Association of State Dam Safety Officials, told EHN.
Just this month in North Carolina, a dam at the state's retired Duke Energy plant failed, spewing ash and coal into the Cape Fear River. That dam had an emergency action plan, but the majority of the state's high-hazard dams do not.
That's not unusual.
Approximately 30 percent of the country's 15,498 high-hazard dams do not have emergency plans. Add in the age and lack of maintenance of many dams, and a flooding disaster is just waiting to happen. And in many places it has happened—according to the Association of State Dam Safety Officials, failures have occurred in every state, with at least 173 failures between 2005 and 2013.
"If you have more intense storms, more frequent storms then those deficient dams can't handle that. And you're going to see more problems where dams are under stress due to the high waters levels or the overtopping," Ogden said.