Plastic streams and impatient brook trout: Buck Creek culvert project shows fast results

Almost immediately, native brook trout moved into the plastic-lined diversion stream. One expedient brookie was often seen feeding on surface insects during even busy construction periods.

By Damon Hearne

The brook trout of Buck Creek are ready to move. In fact, down right impatient may be an understatement. Excavators, construction workers and plastic-lined stream be darned, these brookies are moving on up – and proving that TU’s Southeast Conservation Project is focused on the right stuff.

This summer, TU’s Southeast Conservation Project (the SE Project), in partnership with the U.S. Forest Service, Orvis and others, broke ground on the first in a series of culvert replacement projects on native brook trout streams in North Carolina. This inaugural partnership project removed a perched culvert on the headwaters of Buck Creek in the Nantahala National Forest that had cut off brookies from their headwaters for more than three decades. 

Through TU’s science-based prioritization and close planning with the Forest Service, we chose a site in the Natanahla River’s headwaters that has many advantages. These brookies reside in a climate-resilient catchment, are completely protected by the Nantahala National Forest, and sit at over 4000-feet elevation. We used these facts, and the plight our greatly reduced native brookies to enlist a host of partners to complete this work. In addition to the Forest Service and Orvis, TU is working with the U.S. Fish and Wildlife Service, the Wildlife Conservation Society, the National Fish and Wildlife Foundation, TU chapters and individual donors to complete the project. 

We broke ground on the project in June and immediately saw brookies taking advantage of our progress.

The first step in these projects is to excavate around the old culvert to establish the footers for a new arched crossing. In this case, we also had to remove the old culvert due to the discovery of unstable fill under the site. To accomplish this, our contractor actually moves the stream from one side of the site to the other, and then moves it back. During these phases, the stream flows through a plastic-lined channel. The plastic prevents sediment from washing down stream during the construction phase, and reduces risk that a chance rainstorm does additional damage. 

Remember those impatient brookies? They need cold water, but are not so picky when it comes to opening up new habitat. Within days of installing the temporary plastic-diversion, trout had moved on up. We saw trout in each of the temporary pools, and stacked up at the last cascade in the construction site. These trout were ready for new habitat! 

And talk about perfect sight fishing: One good-sized trout was camped out in the largest of the plastic-lined pools, picking bugs off the water continuously as site work progressed. Seeking shelter under the plastic folds, this brazen brookie would disappear for a few minutes when a worker would step across the stream, and then re-appear to continue the feast. (Rumors of staff trying out a new tenkara rod will not be addressed at this time.)

We’ve now passed the “plastic habitat” stage of the construction and Buck Creek’s trout are now back in native habitat, thanks to our USFS partner hydrologist and a very adept machine operator.  In a day’s time they built a simulated stream through the future crossing, and turned the water back into its final path. The new stream looks like the real deal, and brook trout are no doubt moving on up to the headwaters for the fall spawning season.   

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With the new culvert in place, workers put the final touches on making the road passable. Next up: seeding and mulching the area, and monitoring fish movement.  

The crossing’s “lid” is now installed, and the road is nearly back to passable shape. Once the site is finalized, TU volunteers will come in to help seed and mulch the area and help with post-construction fish monitoring. While the volunteers are spreading straw and seed, we’ll move the excavator up in the watershed and remove a second smaller culvert. That one won’t get the plastic treatment or a new crossing installed – so we won’t even give the brookies of that stream a chance to be impatient. 

Damon Hearne is Trout Unlimited's Southeast Conservation Project director, and is based in Asheville, N.C.