In 2018, I scrambled up Trace Creek’s headwaters for the first time. As I walked, the state of the stream became apparent. On one side of the stream was a steep, forested hillslope; on the other side was an open pasture. This is a common way for a stream to look, but it’s often a hallmark of human interference. To maximize land available for agriculture, waterways are sometimes pushed from their natural course (where they may have meandered through a farm field) up against an adjacent “valley wall.” The practice improves farming efficiency but at the expense of a delicate, natural balance. Healthy streams are dynamic places that ebb and flow as the seasons and rainfall change, but, overall, they are relatively stable and enjoy an equilibrium with their surrounding watershed that has been slowly calibrated by natural forces across millennia. When streams are manipulated by people, many degradatory processes are set in motion.
The further I walked up Trace Creek, the more obvious the degradation became. In places, the creekbed had eroded ten feet or more below what used to be its floodplain. Floodplains are areas of land adjacent to stream banks that slow and soak up stormwater, dissipating the energy of destructive, high flows after a heavy rain. Without floodplains, gently sloped Middle Tennessee streams like Trace Creek, are highly susceptible to erosion. Here in Trace Creek’s headwaters, the stream had completely lost access to its floodplains. Research done on similar streams in the same ecoregion tells us that Trace Creek should carve a gentle, winding, relatively shallow path. Instead, compressed stormwater was moving through a straight channel at a very high volume and velocity. It reminded me of the barrel of a shotgun.
As banks collapse and soil washes downstream, aquatic species and habitat are buried beneath the muck. For over twenty years, the Tennessee Division of Water has reported that Trace Creek “insufficiently supports aquatic life” due to the loss of natural habitat and pollution from silt.
Since 2018, the Compact has led an effort involving stream scientists, environmental engineers, and natural resource agencies – to gain an in-depth understanding of the existing ecological conditions of Trace Creek and to develop a restoration plan for the waterway that will have significant, lasting benefits for area ecology once realized. Today, that restoration project is well underway; over 95% of construction work is complete.
December 2023 – June 2024: Barren to Bountiful
It’s important to note that construction work is only the beginning of the restoration process. When a large stream restoration project requires floodplains to be reconnected or newly excavated, channels to be moved or meandered, and stream beds to be raised, there are substantial ecological impacts. Most painfully, trees must be cleared to return the stream to its natural path – that’s why, in the early construction photo on the left, the ground looks barren.
To replace lost habitat and stabilize the soil on Trace Creek’s new banks and floodplains, we have planted thousands of native trees, grasses, and wildflowers throughout the project area. As the construction team works, they are sowing temporary seed (fast-growing annuals that quickly stabilize soils), sowing hundreds of pounds of permanent seed (native flowers and grasses such as lance-leaved coreopsis and little blue stem), and removing exotic invasives such as amur honeysuckle and privet. When I last visited the site, I was excited to see bearded beggarticks growing abundantly. The plant produces beautiful yellow flowers in late summer, and supports numerous species of native butterflies including monarchs, swallowtails, buckeyes, and more.
In addition to grasses and flowers, and with the help of hundreds of volunteers, the Compact planted 15,000 native trees and shrubs in March of 2024. Plantings included live stakes in stream banks, bare roots on floodplains and terraces, and larger container trees – up to 25 gallons – in upper stream reaches. Sixteen species were planted, with considerations made to promote diversity and survivability throughout. Species that prefer wetter conditions (e.g. river birch and silky dogwood) were planted on the lower elevation floodplains and species that prefer drier conditions (e.g. red bud and spice bush) were planted on the higher elevation terraces.
All species planted on Trace Creek are commonly found along healthy, similarly sized streams in the surrounding ecoregion, and all are native. Our native insects evolved alongside native plants, and most are incapable of consuming exotic, invasive species such as bush honeysuckle and privet. When bush honeysuckle, privet, and other exotic species invade an area, they are, in effect, taking food off the table, sending a cascade of harmful impacts up the food chain. As leaves and branches from native species make their way into our project streams, aquatic insects will have an increasingly abundant supply of food and habitat. These animals will themselves become an important source of food for other species.
The work we are doing on Trace Creek is correcting human-caused, derogatory processes that would otherwise continue for many hundreds of years (e.g. erosion, sedimentation, habitat loss, invasive species colonization, etc), and putting the stream on a path towards restoration. It will take a few years to recover from construction, but after doing so, it will continue to grow healthier and healthier and be forever protected from disturbance by a permanent conservation easement held by the Cumberland River Compact.
Decades from today, Trace Creekcould become one of the most pristine streams in the Outer Nashville Basin. And, thankfully, every passing decade, including the early years of the first, will provide nature lovers with a wealth of natural beauty to enjoy – a progression from flowering, open meadows to richly diverse, riparian forests.
What’s Next?
None of this work would have been possible if the developers of Stephens Valley – Land Innovations – hadn’t reached out to the Compact about stream restoration in 2018. We’re glad they did. The opportunity to complete a restoration project of this size on a suburban site is rare – almost unheard of. But, today, 44 acres of greenspace – a corridor that runs through the developing neighborhood of Stephens Valley and connects to federally protected land in the Natchez Trace – is being restored and protected from disturbance forever. The project is one of the largest suburban stream restoration projects in Tennessee history. In total, 2.6 miles of stream are being restored within the Williamson County neighborhood.
Construction is being completed by Land Mechanic Designs, a stream and wetland restoration company with over 20 years of experience. Stream designs closely mimic the conditions of the surrounding region’s healthiest, least impacted streams and is the work of Ecosystem Planning and Restoration, a company with over 500 projects to their name and over 100 miles of stream restoration experience.
The last of the construction work – and the sowing of flower and grass seed – will be completed in the summer of 2024. When the next planting season begins in Tennessee (late Fall to early Winter 2024), approximately 15,000 more trees and shrubs will be planted throughout the upper half of the project. Scientists at Ecosystem Planning and Restoration have set up monitoring stations at various places throughout the project’s 44 acres, and the instream conditions and vegetation of the site will be monitored for the next seven years. Monitored indicators of stream health will include stream flow, aquatic habitat, bank erosion, native plant density and diversity, invasive species, and more. During this time, the Compact will take corrective actions as needed to ensure that significant, measurable ecological gains are being made. All 44 acres of the project are protected from disturbance by a permanent conservation easement held by the Compact.
We look forward to seeing Trace Creek grow strong in the years to come. We live in a rapidly developing world where habitats are increasingly fragmented, and where an alarming number of species (including species that have made a home in Tennessee for hundreds of thousands of years) are in serious trouble. The restoration of Trace Creek will provide 44 acres of invaluable support and safe passage for these species, right within a suburban neighborhood and between two points of federally protected land. In the coming months and years, residents can expect to see flowering beggarticks, monarchs and passion butterflies, playful goldfinches, fast growing tulip poplars, and irrepressible willows throughout the easement area. It’s a special project whose unique location and scope will provide a template for other projects in the future. For our part, we are going to continue to work hard to ensure that the project is successful and that the benefits to Tennessee’s invaluable ecology are significant and stand the test of time.
