Finding new homes for hellbenders on the Watauga River

During his seven-year stint as MountainTrue’s High Country regional director and Watauga Riverkeeper Andy Hill has planted thousands of native plants, sampled water at streams across the region, reviewed reams of pages of government policy, and spent many hours on porches with local land stewards.  He’s also helped remove two dams and transplant protected hellbenders.

After a morning rain-shower on Sunday, June 30, Hill and a dozen others including Erin McCombs of American Rivers stood on a rise above the Watauga River, watching as a Caterpillar excavator dug its mechanical thumb into the 100-year-old Shull’s Mill Dam near the site of a former lumber town.

Located seven miles from Boone, this marked the beginning of a roughly two-week process to demolish the dam and restore the river’s natural flow.

“It’s a dream come true — I’m feeling very grateful, very excited and relieved.” Hill said.

“One of the things I’ve learned is the quickest way to jump start a river’s recovery is to remove any barriers. It opens up new pathways for aquatic connectivity, people can paddle through safely, and we’ve got a great new living classroom to jumpstart our rewilding efforts.”

Supported by local conservationists, engineers and wildlife biologists, its removal aims to enhance biodiversity, improve water quality, and reconnect populations of fish and aquatic animals interrupted by the structure.  The controlled demolition is designed to minimize the impact on the river’s ecology in the short term and in the long-term, improve the river’s resilience to climate change.

The Shull’s Mill Dam project is one in an expansive effort to remove obsolete and aging dams in Western North Carolina and throughout the U.S. The razing is spearheaded by a coalition of organizations including MountainTrue, the NC Wildlife Resources Commission, U.S. Fish and Wildlife and American Rivers utilizing state and federal funds.

When Hill started as riverkeeper in 2017 “dam removal didn’t seem like a realistic policy or project goal,” he said. Soon after his start as riverkeeper, however, Hill met McCombs, American Rivers’ Southeast conservation director, discovering that her organization was actively and aggressively pursuing multiple removals.

According to McCombs, Shull’s Mill Dam was one of roughly 27,000 dams throughout North Carolina, many of which are no longer serving a purpose. American Rivers is a leader in the movement to remove dams and has a lofty goal to raze 30,000 dams by 2050.  In 2023, 80 dams were removed nationwide.

Together, they began discussing the possibility of ousting the remaining two dams impeding the Watauga River in North Carolina. The first, the Ward Mill Dam, was removed in May 2021.

“Removing a dam is the fastest way to bring a river back to life,” she said, by allowing sediment to spread normally and allowing insects, invertebrates, fish and other aquatic animals to flourish.

Among them, the eastern hellbender, a giant salamander that’s one of the region’s most iconic river species. Expanding the native range of hellbenders is a key aspect of the dam removal.

“It’s really cool to see this project through the eyes of hellbenders,” she said on June 30 over the din of the deconstruction equipment.

“To heal a river is really special.  It’s been years of hard work to get to this moment. I just feel so grateful that I get to work with so many people who are after the same thing: which is a river reconnected and restored.”

Hellbenders of the Watauga River

Appalachian State University freshwater conservation biologist Mike Gangloff has monitored hellbender populations in the Watauga River since 2008 and is contracted to advise on the impact of the dam removal.

“Dam removal is something that I’ve been interested in, especially these smaller dams, which are much more common in the Southern Appalachian landscape,” Gangloff said.

The Shull’s Mill Dam, which once powered a sawmill and thriving community, was breached in 1940 following a devastating flood. For decades, the river’s concentrated flow gushed through a gaping, mushroom-shaped hole in the dam, as if a fire hose, into a large pool.

Despite the opening, for decades the structure impeded the river, causing significant geomorphological distortions: an altered flow, masses of sediment, and a scoured streambank.

“Our research has shown throughout the southeast that these breach dams should be the ones that we focus on,” Gangloff said.

Removing it will restore the river’s natural course and stabilize the habitat for river creatures, including Eastern hellbenders, a giant salamander that has inhabited the rivers of the eastern United States for eons. Their presence on the river is an indicator of stream health, he said.

The creatures, some as long as a human forearm, absorb oxygen from water through their skin. Once widespread, hellbenders now occupy only about 10% of their historical range, finding refuge in waterways like the Watauga, where the upper stretches are shaded by forest.

But dams result in warmer water with reduced oxygen levels and layers of silt. The blanket of sediment poses a significant threat to salamanders who require environments with clean flowing water and shaded riparian areas.

Relatively high concentrations of hellbenders are present in sections of river further upstream and downstream of the dam, however, the structure was a barrier to migration so divided groups didn’t connect, isolating them and narrowing genetic diversity, which hampers the species ability to adapt to environmental threats, such as climate change.

Despite not-so-ideal conditions in the tail waters immediately below the dam, it’s hellbender territory.

Gangloff and his team have identified several of the giant salamanders with established dens in the pool below the dam, at least one nest deep within a fissure of the concrete itself.

So, prior to destroying the dam, it was essential to move them.

Transporting salamanders

“They’re homebodies,” said Hill. “When they find a place they like, they stay put and that’s likely where we’ll find them.”

A week prior to the dam’s demolition on Monday, June 24 a trio of scuba divers including Hill, ASU student Robert Adams , and NCWRC technician Ben Dalton squeezed into their wetsuits to dive for hellbenders.

Biologist Lori Williams of the NCWRC told CPP that, since hellbenders are a species of special concern in North Carolina, a state permit is required to search, handle, research, survey or monitor them. It’s also illegal to harm, kill, collect or sell a protected species. Violations are a class I misdemeanor, punishable by a fine and up to 120 days in jail.

Despite their predilection to linger in their dens, in the swirling current below the dam, it’s hard to see your toes in the murky water let alone spot a salamander behind a scuba mask, some of them in dens 10-15 feet below the surface.

The challenge for this team of experts is spotting the surveyed hellbenders, whose mottled skin camouflages perfectly against the river’s rocky bottom in the murky water.

In all, Gangloff’s team of students has previously identified a handful of hellbenders in the tailwaters below the dam, but there may be as many as a dozen underneath flat river rocks where they build dens and feed on crayfish. To breed, they require the rocky cavities to lay eggs in the autumn; the male denmaster protects the eggs and larvae until they emerge in late spring.

Hill plunged into the pool, his bright yellow oxygen tank fading as he disappeared beneath the water and probed the perimeter of a large boulder below the river’s surface.

After nearly an hour of meticulous searching, the divers emerged with the first of three hellbenders to be relocated. Hill carefully held the first creature apprehended in a mesh net, keeping it submerged until handing it to Dalton of the WRC, who weighed and measured it, assessing its health.

Tagged with an internal transponder in its fatty tail for monitoring, the male Hellbender was 500 grams, roughly the bulk of a bag of rice. Approximately two decades old, it could be distinguished by a missing rear foot, likely lost to a predator or in a tussle with a fellow salamander.

By midafternoon, the trio of hellbenders were placed in an aerated cooler with chilled water and transported to a spot on the Watauga several miles downstream. Over three days of searching, the team of divers relocated nine Hellbenders, who will hopefully expand their territory to a recently restored section of the Watauga in which the giant salamander was absent.

One notable aspect of this project is the extensive data collection before, during and after the dam removal, addressing the current lack of information on dam removals and informing future demolition projects.

A week after moving the Hellbenders, McCombs raised her voice above the clamor and the banging of an excavator as it shattered a section of concrete that was moments ago a part of Shull’s Mill Dam.

Collaborating with Appalachian State University and Gangloff, she said, is significant in which experts and students contribute to research, monitoring, tagging, and habitat surveys, producing valuable data over many years, even decades.

“We’re continually trying to make the practice of dam removal better on the environment,” McCombs said.

“We’re really fortunate that our funding partners supported the ability to include monitoring, because that’s often one of the first parts that gets taken out of a project, so we’re really pleased to be partnering with WRC and ASU to get some really good data. That’s something that really sets this project apart from other removals.”