In the next 50 years, 2 million American shad may begin reaching their spawning grounds on the Susquehanna River, which flows through Maryland, New York, thanks to planned upgrades to Conowingo Dam, the first major impediment the fish face on their journey to reproduction. This potential increase in spawning shad is the result of a new deal struck last week between the U.S. Fish and Wildlife Service and Exelon, the Chicago-based energy company that leases Conowingo. According to the Washington Post, Exelon will enhance the lifts that transport fish from the bottom of the dam to the top, 100 feet above. Additionally, the company will transport additional fish upstream via truck to help them reach their spawning grounds. These arrangements come as part of the renewal process for Exelon’s 50-year federal operating license for Conowingo.

FWS has high expectations for reviving the spawning runs, despite dwindling shad numbers over the past 15 years. According to the Pennsylvania Fish and Boat Commission, in 2015, only 8,341 shad passed through Conowingo Dam, which stands just south of the Pennsylvania–Maryland border. Those numbers have plummeted since fish passage reached 193,574 in 2001.

In 2013, the Baltimore Sun reported on the difficulties posed to American shad by the Conowingo Dam. During that run, only 12,733 fish successfully navigated the dam by hitching a ride up its fish lifts. Michael Hendricks, a fisheries biologist with the PFBC, said that biologists have struggled to explain the plummeting number of shad, given the number that once passed through the dam.

As a result of the shad downturn, Exelon faced pressure to improve the fish lifts from environmental groups. Exelon voluntarily withdrew the application to renew its lease on Conowingo in 2015 to work out an out-of-court settlement. That settlement ultimately included the current plans to aid shad in their annual spawning run. Exelon spokeswoman Deena O’Brien said that the resolution makes wildlife advocates happy while providing the company with a quick renewal of its lease.

Sheila Eyler, a FWS project manager in the service’s Mid-Atlantic office, told the Post, “We’re anticipating the fish populations will grow over time, and the needs for fish passage will grow.” Because the license lasts 50 years, deals like this only come around once a career, if they happen at all. Outside of issuing a federal operating license, Eyler said, “We don’t have a mechanism to come to a dam owner and ask them to do something.”

Photograph courtesy of U.S. Army Corps of Engineers/Flickr