If you build it, they will come: Designing a self-sustaining trout stream
April 27, 2016
April 27, 2016
It takes a multi-disciplinary team – and lots of research on trout life cycles – to restore a stream to sustain new life
There is nothing like trout fishing along a pristine stream. I’ve had the opportunity to enjoy this experience a number of times in beautiful natural settings like those in Montana. Now, imagine – as an avid fisherman – your team is asked to create a pristine trout stream at a site very close to home with all the extras you see on those great trout streams from afar. Our River Restoration Group at Stantec was presented with this unique, once-in-a-career type opportunity (and challenge) just a few years ago with the Hatchery Creek Stream Restoration project, and it was every bit as enjoyable as you’d imagine!
Hatchery Creek is unique because the source flow is cooled by the depths of Lake Cumberland and flows through the Wolf Creek Dam National Trout Hatchery near Jamestown, Kentucky, where rainbow, brook, and brown trout are hatched and raised. Prior to initiating our work, the stream flowed 400 feet through the most heavily-fished stream in Kentucky, then down an eroding ravine into the Cumberland River just downstream of the Wolf Creek Dam.
Our challenge with this design/build project was to provide mitigation credits for our client (Kentucky Department of Fish and Wildlife) while creating a 6,000 foot long self–sustaining trout stream. Because many of our streams in Kentucky are too warm, self-sustaining trout streams are very scarce. Although the water just below Lake Cumberland dam is cold enough to support trout, water level fluctuations from the operation of the dam prevent successful spawning.
There were many unique aspects about Hatchery Creek that we don’t typically encounter when designing stream restoration projects. First, under normal conditions the channel flowed at 30 cubic feet per second, which was very high compared to the contributing drainage area of the watershed. We needed to build a gravel stream in a watershed that would not naturally replenish the sediment. We also needed to provide fish passage up from the Cumberland River into our stream, while creating a migration barrier to keep large female trout from getting into the original Hatchery Creek channel due to different fishing restrictions between the new and old channels.
I clearly remember gathering our team together for the conceptual design. We were excited about the possibilities of what we could create here, but knew we’d need the right crew to get this done. So with a multi-disciplinary team that included engineers, biologists, ecologists, vegetation specialists, avid fisherman, and contractors, we began the project with great enthusiasm.
Gathered together at Lake Cumberland State Resort Park, we reviewed the entire site and then focused on developing the conceptual design with no distractions. We literally drew the different life stages of trout on a board and discussed the optimum stream types and habitats needed for each life stage. Through this collaborative effort, we produced a unique design which included high gradient and low gradient single-thread meandering reaches (C stream type), multi-thread braided reaches (DA stream type) and a steep step-pool reach (A stream type) to serve as a “fish ladder” between our project and the Cumberland River.
We completed the project last November and introduced the flows into the creek for the first time just before Thanksgiving. We were confident that the project would allow trout to migrate into our channel from the Cumberland River, but would they come? How would everything look once flows were turned into the new stream? How quickly would the food sources make it into the stream? Much to our amazement, trout began using the stream instantly and, within two weeks of turning flows into the channel, we had evidence of trout spawning. The movement of trout into the channel has been so swift that stocking the channel wasn’t necessary – we already have an abundance of trout for fishing!
This week is the ribbon cutting ceremony, which marks the official grand opening of the project to the public. I’m so grateful for the opportunity to have worked on what is, for me, a once-in-a-career project to bring a self-sustaining trout stream to the citizens of Kentucky. I’m extremely proud of our team – every member displayed such passion for this project and gave their best effort to make it a success. I’m also proud to work for a company that supports research and development. The project received a Stantec R&D grant to help study how trout use the wood structures at Hatchery Creek, and to study a trial device that creates artificial upwelling within the spawning gravels. This research, coupled with research being conducted by our client and Murray State University, will help future stream designers continue to create sustainable trout habitat all over the country.