By Page Leggett
Consider the eel.
Unlike most eel species, which live in saltwater their entire lives, the American eel spends most of its life in freshwater before returning to the Sargasso Sea to spawn.
It’s probably their final journey, but scientists say much about their life cycle remains a mystery, said Mike Abney, a project manager with Duke Energy, whose expertise comes from a decades-long effort to restore eel populations in the Catawba-Wateree and Pee Dee rivers.
But eel aren’t the only species making a comeback. Duke Energy is also reintroducing American shad, another migratory fish that, in reverse, hatches in rivers, matures in the ocean, then returns to freshwater to spawn.
A 100-year homecoming
Historically, eels thrived in the Pee Dee River, but in 1912, a Duke Energy dam near the North Carolina/South Carolina border blocked their migration to generate electricity that would drive the region’s economic growth.
“As the U.S. developed, rivers were altered for industry, power, and infrastructure. One of the drawbacks, however, was reduced habitat for some species,” said Jason Brown, lead Environmental Health & Safety (EHS) consultant at Duke Energy.
A newly constructed eel ladder at Blewett Falls Hydroelectric Station in Lilesville, N.C, is changing that. To date, nearly 18,000 still-maturing eels have taken up residence in the waters near Blewett Falls Lake.
“By restoring access to hundreds of miles of habitat, the American eel can access previously blocked upstream riverine habitat. We want to bring the river systems back to what they once were,” Brown said of the company’s work to enhance environmental habitats for fish and other aquatic life.
How the eel ladder works
The ladder guides eels upstream using flowing water and was designed with help from the North Carolina Wildlife Resources Commission, U.S. Fish and Wildlife Service and the National Marine Fisheries Service (a division of the National Oceanic and Atmospheric Administration – NOAA for short).
“Eels sense moving water and follow it to continue their migration upstream,” Brown explained. “We provide flow by pumping water from the lake down a long ramp. That gets them over the dam and into the lake.”
Eels travel up the ladder, which consists of five aluminum ramp sections connected by resting pools, and into a collection tank where the team counts, measures and weighs them – both to ensure they are healthy and to track how many eels migrate each year. Then, the eels are funneled to Blewett Falls Lake.
Eventually, Duke Energy will phase out manual collection, allowing eels to migrate independently – a Duke Energy first. Their lifespan in Blewett Falls Lake is about eight to 10 years, Brown explained, so they’ll likely be here for an extended stay before instinct lures them back toward the Sargasso Sea.
Shad make their return
Unlike eel, shad are picky about their migration routes. “The eel ladder is simple and runs on its own, so you don’t need a person on-site to operate it,” Abney said. “American shad, however, required a more sophisticated approach.”
Siting studies were done to position both facilities in the right spot. “We did extensive studies back in 2015 and ’16 to see where the majority of eel and shad congregate,” Brown said. “Had we not, we could’ve constructed them in the wrong spot.”
Migrating shad are similarly attracted toward flowing water, but the shad facility lifts collected fish up two levels where they are sorted through a system of tanks. This requires a dedicated team of scientists to carefully examine and sort the shad from other species.
American shad are loaded into a large tank on the back of a pickup and transferred above the dam and into the lake, while other fish and aquatic life return to the river through several large pipes.
Conservation in action
Blewett Falls Lake remains a popular destination for boating, swimming, and fishing – but anglers must release any American shad they catch.
“If there’s one in Blewett Falls Lake, that means we passed it,” Abney said. “And if we’re putting in all this effort, we don’t want people taking them home.”
For Abney and Brown, seeing these species return is deeply rewarding. “Watching critters use the passageway we created – and in large numbers – is gratifying,” Brown said. “It’s a key milestone in my career.”
Many who helped launch the project have since retired. “When this project was first discussed, we talked about it taking decades,” Abney said. “John Crutchfield, one of our project managers retired. He was instrumental in those early discussions.”
Though this restoration took years, its impact will last for generations. “I want my kids to enjoy what I got to experience growing up,” Brown said. “This project builds a bridge to the future.”
Also happening at Blewett Falls
Alongside efforts to restore migratory eel and fish populations, Duke Energy has enhanced its water management system at Blewett Falls Hydro Station with new spillway gates designed to enhance operational efficiency and lake management.
The gates allow for more precise control of water levels, improving conditions in Blewett Falls Lake and downstream areas. Their modular design simplifies maintenance, while a pneumatic support system ensures reliable operation – even during power outages.
The gates also allow for safe passage of floodwaters, helping protect upstream properties by minimizing the risk of overtopping.
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