New pact demands more from Conowingo Dam operator
— If the Federal Energy Regulatory Commission approves the license for the Conowingo Dam, officials from Exelon Generation will have to work harder to help endangered fish get up the Susquehanna River.
Sheila Eyler, project leader with the U.S. Fish and Wildlife Service Mid-Atlantic Fish and Wildlife Conservation Office, said a new contract has been designed that would require operators at the dam to do more for the anadromous species that need to get to the top of the river to spawn. This includes American shad, alewhite and blue back herring and the American eel.
“Like the shad, the herring spend most of their life in the river but they mature faster,” Eyler said. “They all spawn in the river like the shad.”
But overfishing combining with the construction of four dams — Holtwood, Safe Harbor, York Haven and Conowingo — have blocked these fish from reaching spawning grounds in the Susquehanna River in New York.
Exelon operates a pair of fish lifts at Conowingo that only do half the job FWS requires, Eyler said.
“The east lift is not efficient. Only 30 to 40 percent is moved,” she said.
The west lift is worse, she added. The goal is to meet 85 percent during the new license, which will last for 50 years.
“The hopper lifts fish to the top of the dam,” Eyler said.
However, since it is not selective it carries every fish, not just the target species.
“Part of the improvements they will have to make is to add another hopper, and add larger ones,” she said.
And a transport method that dam officials ceased in 1996 will make a return, Eyler said.
“Shad and herring have to pass three other dams,” she said. “We know that 40 percent is lost at Holtwood, 20 percent at Safe Harbor and all are lost at York Haven.”
According to Deena O’Brien, Mid-Atlantic communications manager for Exelon, the “trap and transport” method was used from 1972 until 1996.
“When the volitional fish passage was completed at all of the hydroelectric facilities on the lower Susquehanna River, the trap and transport program was discontinued,” she said.
Fish and Wildlife officials are requiring that fish be trucked above York Haven with the hope of capturing 55 percent of the fish heading for spawning grounds. It’s 60 miles over land.
Eyler said Exelon also needs to do more to make the fish lifts inviting.
“They are competing with flows. They have to make it so the fish can find the entrance,” she said.
Along with the capacity, time is another factor being considered, O’Brien said.
“We will also be reducing the time it takes to complete a single lift cycle,” O’Brien said.
Tagging fish by Exelon will come at a later date, although Maryland Department of Natural Resources already does some tagging at Conowingo.
Sediment is an ongoing a topic of discussion. That’s been a hot button issue with legislators, engineers and conservation groups debating the merits of dredging behind the dam to remove decades of buildup. A study released a year ago found dredging to be a waste of money. Meanwhile, a U.S. Army Corps of Engineers study in March ruled that nutrients, not sediment, is the enemy.
Eyler said the fish lifts were part of “a whole suite of improvements” that dam officials need to accomplish in order to meet specific goals set by FWS.
“Every five years, we’ll do a study to see how many fish are using the lifts,” she said.
Eyler said the cost to Exelon is not among the concerns.
“It’s up to them to estimate the cost,” she said. “We want the fish to pass efficiently. We don’t really care if they find a low cost way to do it.”
The new goals and requirements do not go into effect until the new license has been issued.
Its license expired in Sept. 2014, but FERC issued Exelon a temporary licensing while the issues are sorted out. That temporary license expired in March, according to American Rivers, a conservation group.