By Lyn Benjamin
Executive Director
As Friends of the Teton River moves forward with its work to protect water resources in the Teton Valley, stream restoration plays an increasingly important role in improving conditions for fish and other aquatic life. Over the next two years, FTR will sponsor restoration projects in five areas on the Teton River and on two miles of lower Fox Creek. We are often asked “What is stream restoration and why is it so important?” In this article I’ll discuss the reasons for our commitment to restoration work, how we plan on implementing restoration goals, and the results that we hope to see.
Why restore stream systems and
what do we mean by restoration?
Well let’s start with the two photos shown above. The top photo shows a heavily degraded streambank below South Bates Bridge on the Teton River. The bottom photo shows a site below Bates Bridge, which has willows, grasses and sedges on the left bank and a newly formed island close to the right bank. The first difference is clearly aesthetic; it is more attractive to float by green, vegetated banks than bare banks that are crumbling into the river. Although looks are important they aren’t everything (remember what your Mom told you so many years ago?); similarly, beautification is not the main reason for stream restoration. Let’s look a little more closely at the photos and think about the living parts of the stream system and what they need to function best.
Trout need clean, cool water; a river bottom with gravels that can be used for spawning; deep pools, pieces of wood in the channel, and overhanging vegetation for protection from predators; bugs to eat; and river margins with sedges where young fish can hide.
The photo on the bottom is an example of how a healthy stream can provide all these things. In the photo the stream system is functioning at its best. The overhanging willows on the bank are very important because they provide shade to cool the water, cover for trout from overhead predators like blue herons and osprey; hold the bank soils together and stop silt entering the stream; provide organic material for trout and bugs to eat; and finally, as they get old, fall into the stream and become woody debris cover for trout. The newly formed island narrows the channel hence increasing the current speed and removing silt from the stream bottom (and making those wonderful gravelly tail-outs where fish can spawn). When the sedges growing on the island are partially inundated by water they provide juvenile trout habitat. The eddy line between the backwater, created by the island, and the flowing current is a great place for fish to feed. It is beautiful to look at but it also provides ideal conditions for fish to thrive.
Areas of a river with degraded banks provide none of the features that I’ve described and also add fine silts to the streambed. The silt covers the spawning gravels and fills up the spaces between the gravel that insects like mayflies, stoneflies and caddisflies need to survive. Reduction in trout spawning and loss of bugs to eat can be a result of bank devegetation and degradation. Additionally, in hot dry summers, like the one we have just experienced, lack of overhanging willows can cause a rise in stream temperature, reduced oxygen levels, and eventually fish mortality.
So, the reason we restore streams is to improve how they function and thus hopefully turn around the decline in trout populations that have been documented for the past 20 years.
How do we restore a stream?
I’ll describe two projects that FTR has started this summer that provide excellent examples of approaches to restoration. On the Teton River we have selected five sites where stream banks have been heavily eroded and where landowners are interested in improving fishery habitat. Thanks to funding from U.S. Fish & Wildlife Foundation, One Fly Foundation, the Donald C. Brace Foundation, National Fish & Wildlife Foundation, 5 Star Restoration Challenge Grant, the Peninsula Community Foundation and the Arthur B. Schultz Foundation we will keep doing restoration work on the Teton River.
The approach to streambank restoration consists of bank stabilization and revegetation. Banks are contoured to a 4:1 slope and covered with an erosion control fabric and topsoil into which willows are planted. Wetland sod (consisting of native grasses and sedges planted into a coconut fiber matrix) is then placed over the newly created terraces. Areas of the bank that are further from the stream are then seeded with native grasses. The result is stable banks with willows, grasses and sedges whose growth will prevent future erosion and create optimal conditions for aquatic life.
FTR is also starting an ambitious project to restore two miles of lower Fox Creek from the springs to just above its confluence with the Teton River. Fox Creek is considered one of the most critical spawning tributaries for the Teton River. Historically banks were covered in willows, grasses and sedges; however, much of the area was devegetated about forty years ago and has resulted in bank erosion, silt covered stream substrates, and loss of fish and wildlife habitat. We have initiated a cooperative project with Blaine and Nancy Huntsman, Teton Valley Trout Unlimited, the Teton Regional Land Trust, and the U.S. Army Corps of Engineers to revegetate and restore stream banks along Fox Creek. We also hope to restore instream trout habitat by creating holding pools for adult trout, placing large woody debris and log current deflectors, and adding spawning gravels. This is a three year project scheduled for completion by spring 2006.
These projects are the first of many that FTR hopes to tackle in the future. Stream restoration is one of the keys to a healthy aquatic system. |
