On August 30th, the Adams Soil and Water Conservation District co-hosted a tour with the Idaho Department of Environmental Quality to see riparian habitat improvement projects in the Little Salmon River watershed.
Our first stop was at Four Mile Creek. This was a project that added more vegetation as a riparian buffer and a fence around the stream bank. A vegetation strip provides a buffer to flood waters and filters runoff into streams. The vegetation adds additional shade to the creek, keeping the water temperatures cool. Also, the growth provides shade for the cattle in the field. The photo shows a water gap with a hardened crossing for livestock, and the top of the photo shows a livestock exclusion area. The crossing area is appropriately wide, sloped and hardened with rock so that livestock do not tramp the banks into mud.
Our next stop was further down Four Mile Creek, as another land owner was rebuilding part of the riparian habitat. We saw a number of willow plantings, using a technique called “willow weaving”. This is used to stabilize eroding stream banks without the use of heavy equipment. A water pump connected by a garden hose to a “stinger” is used to bore holes with pressurized water at an angle from the top of the stream bank down to just above the water line. A long, straight willow stem is then inserted into the hole extending down through the bank and into the stream. This leaves a gap from where the willow stem comes out of the bank, and down into the stream bottom. Cut willow stems are then woven between the stems to form a very tight protective mat along this gap. Once these cuttings begin to root and grow, they provide an excellent protection for the stream bank.
Our last stop was the Little Salmon River near Four Mile Creek. Riparian buffers, livestock fencing, and other techniques have been used to slow the erosion of the stream bank. The photo shows an area where planting had occurred on the banks, but due to the dry hot summer, the plantings were struggling despite their attempts to water them weekly. The point bar on stream left is doing well with many willows, but is pushing the river into the higher, opposite bank which is eroding because it does not have much woody vegetation yet. This is the way streams attempt to get their meanders back. Encouraging natural meanders will help slow the flows in high water, allow sediment deposition, eventually raising stream beds and narrowing the channel. Over time, this will allow water to remain on the fields longer and release water more slowly back to the stream. More planting on the right bank will help stabilize these banks. If the plantings are protected from livestock for a period of time and livestock are properly managed afterward, the banks should recover quickly.
Thank you for such a great tour!