Nantahala River Trout Are in Hot Water. Literally.

What happened last weekend on the Nantahala River tailwater did not seem to command any front page headlines. No major news alerts, no breaking news reports, nada. But once the fly fishing community found this post from head guide and owner of Turning Stones Fly Fishing, Gordon Vanderpool, word spread faster than a California wildfire.

Why Warm Water & Trout Don’t Mix

Hold on… what?! Why in the hell would Duke Energy release water from the top of Lake Nantahala?

If you’ve ever fished tailwaters before, that probably looks like a misprint. Tailwater fisheries maintain consistent temperatures year round from the release of water at the bottom of dams, siphoning off the cold, clean water found in the reservoir’s depths instead of the warmer water near the surface. This colder water provides a safe, healthy environment for trout. Water temperatures are particularly important in the Southeast, where summer temperatures can soar into the 80’s-90’s on the regular.

IMAGE CREDIT:    Trouts Fly Fishing

IMAGE CREDIT: Trouts Fly Fishing

Where the water feeding the river comes from makes a huge difference. The chart above, from Trouts Fly Fishing, shows the temperature range in which trout can thrive. Not much margin for error here - if the water temperatures rise above 70 degrees, the trout will struggle to survive. And if that 70 degree water warms by just 5 degrees, the death of the trout is all but guaranteed.

It doesn’t take a biologist to understand that, in the middle of the summer, the water at the top of a lake is significantly warmer than that at the bottom. In the case of the Nantahala Lake, the temperature down in the depths ranges from the low to mid 50’s. When this cold water is released into the river from the bottom of the dam, it creates an ideal habitat for trout. But when warm water is released from the top of the dam, river temperatures rise in a hurry.

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So What Exactly Happened?

Heather Danenhower, a spokeswoman for Duke Energy, told the Citizen Times “An equipment malfunction on July 23 prevented Duke Energy's Nantahala Hydro Station from releasing water from Nantahala Lake into the Nantahala River”

Wait… So a bunch of fish died because a power company screwed up?

Not exactly. Duke Energy, as operator of the Nantahala Lake dam, was legally obligated to release the water.

Usually, a 9 kilometer pipe feeds cold water from the bottom of Nantahala Lake into the river. But after a generator failed and could not power the dam’s turbine, water flow screeched to a halt. Subsequently, water levels on the Nantahala dropped and everything/everyone downstream felt the repercussions

Dams, like the one on the Nantahala, are licensed and regulated by the Federal Energy Regulatory Commission. Along with that license from the FERC come certain provisions; one of which is the protection of businesses downstream of the dam that operate on the river.

In an email to the Citizen Times, Danenhower states “The Federal Energy Regulatory Commission required this action as part of our license to ensure lake-level management and whitewater recreation water flow releases”

Meaning Duke Energy is required to release enough water from the dam to maintain lake levels and, more importantly in this case, provide a high quality rafting environment for the whitewater outfitters downstream. When Duke could not release water from the bottom of the lake due to the turbine failure, they had no choice but to partially open the spillways on top of the dam to feed the river with more water.

The spillway gate was opened on July 24th and was “immediately closed” on July 28th after a team of biologists employed by Duke Energy discovered dead Nantahala River trout. It quickly became obvious the fish were killed by the wave of 70+ degree water that now coursed through the veins of the river.

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The Body Count

The Citizen Times published their coverage of the story on July 30th. At the time, at least 200 trout were found dead. However, as of the publishing of this article on August 4th, the final body count has yet to be determined. Whenever NC’s Water Resource Division receives reports of a fish kill, they contact the NC Wildlife Resources Commission to investigate. Duke Energy continues to update their kill estimates, which initially only found “about two dozen” dead trout.

Three things are true in this situation:

  1. Duke Energy did everything in their power to follow the law and fulfill the FERC license requirements.

  2. Whitewater rafting is an economic juggernaut for the Nantahala River and outfitters are indirectly protected via federal regulations.

  3. Equipment malfunctions like these can be devastating to a fishery and leave a major negative impact on the Nantahala’s trout fishing industry.

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The Best of a Bad Situation

The equipment failure forced Duke Energy into a lose-lose situation. They could either…

A) Do nothing and wait for turbine to be repaired while the low water kept getting lower. This would put a choke hold on the rafting economy downstream, violate federal law, and almost guarantee the energy company loses its FERC license.

OR

B) Release water from the spillways on top of the dam to keep flows up to code. This would keep Duke in compliance with federal regulations and provide the whitewater playground on which the rafting outfitters make their living. But it would also mean taking a massive gamble with the lives of the trout, the health of the fishery, and the livelihood of the fishing guides that have made the Nantahala their home.

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In reality, there was not a choice to be made. Duke Energy had to comply with the law and the trout population took a hit. Hopefully I’m wrong on this one, but it seems like 200 dead fish is on the low side - especially considering the density of the Nantahala’s wild and stocked trout populations. A TON of fish live in this river and I would think the effects of the release would be a little more widespread.

But like I said… Hopefully I’m wrong.

Stay tuned: I’ll be updating this article as more information is released from Duke Energy and the various North Carolina state departments involved in the matter. Thanks for reading.