Knife River Habitat Rehabilitation-Phase VI
Historic Knife River flooding has led to stream channel degradation. This degradation resulted in slumping streambanks, sediment discharge exceeding the total maximum daily load (TMDL) and the loss of instream trout habitat. This is LSSA's 6th LSOHC Grant proposal in the Knife River. Since the LSSA began grant work on the Knife River (2013), the DNR has observed a 215% increase in the adult steelhead population. Our LSOHC projects have also stabilized ~2 miles of stream channel, restored ~15,000 feet of streambanks and reduced annual sediment discharge by 700 tons. For more information go to www.steelheaders.org.
PROBLEM TO BE ADDRESSED
The Knife River's forest has changed over the past century, which has led to instability of the stream channel during flood events. This channel instability has resulted in significant streambank erosion, channel widening, streambed downcutting and loss of trout habitat.
The LSSA's LSOHC grant projects have attempted to reverse this channel instability by restoring the underlying causes of these stream impairments, while at the same time improving the overall trout fishing. Our previous LSOHC projects have achieved this goal by stabilizing ~2 miles of stream channel, restoring ~15,000 feet of streambank, reducing annual sediment discharge by 700 tons, replanting thousands of trees/shrubs and observing a 215% increase to the adult steelhead population. This 215% increase occurred when two prominent Lake Superior Tributaries saw their steelhead return decrease (Brule River -4.5% from average) (Portage Creek -201% from 2007).
The LSSA and DNR have worked together to identify three priority restoration reaches. These three restoration project sites will not only rehabilitate key trout habitats and restore fishing opportunities, but will also reverse the historic ecological damage to the watershed by stabilizing streambanks, reducing erosion, minimizing sediment discharge, decreasing turbidity levels, reconstructing riparian wetlands, reducing downstream flood impacts and reestablishing instream trout habitat in the watershed.
SCOPE OF WORK
- Assess, survey and design the stream reach(s) to obtain a permit to DNR and Army Corp of Engineers.
- Obtain baseline assessment data.
- Restore the stream channel's shape, dimension and profile.
- Remove flood debris and sediment from the streambed.
- Enhance instream trout habitat by strategically positioning large woody debris, rock structures and ?J? hooks into the channel.
- Create new floodplains/wetlands.
- Reconnect the river channel to the floodplain.
- Raise groundwater table.
- Stabilize streambanks.
- Rehabilitate riparian tree canopy.
- Monitor water temperature.
HOW PRIORITIES WERE SET
The MPCA identified erosion areas within the Knife River Watershed during their TMDL study. The LSSA has assessed these MPCA identified erosion areas, along with other watershed reaches, for the presence of cool water, availability of trout and potential to restore stream impacts. This has allowed LSSA to prioritize areas for restoration that provide the best benefit for aquatic life and improved water quality. The LSSA also has a policy to work from an upstream to downstream manner. Our top-down restoration approach eliminates re-impacting previous restored reaches and reduces downstream flooding and sedimentation.
Urgency and Opportunity of the Project
Reach 8 and 13 are within prime trout habitat sections of the Knife River and by restoring these areas, we can improve trout spawning success and juvenile retention. Restoring the Lower River improves adult trout access to the spawning grounds. This Lower River project also restores a historic but now lost fishing opportunity in the Knife River. This Lower River fishing area was once revered as one of the premier areas to catch steelhead.
STAKEHOLDER INVOLVEMENT
The LSSA has consulted and collaborated with DNR Lake Superior Area Supervisor, DNR Duluth Area Fisheries Supervisor, DNR Region 2 Stream Specialist and private landowners.
$467,000 the first year is to the commissioner of natural resources for an agreement with Zeitgeist, a nonprofit corporation, in cooperation with the Lake Superior Steelhead Association, to restore and enhance trout habitat in the Knife River watershed. A list of proposed enhancements must be provided as part of the required accomplishment plan.
Healthy populations of endangered, threatened, and special concern species as well as more common species - By funding this project, anadromous and stream trout populations should increase. This project will also provide habitat to invertebrate, amphibians, reptiles, birds and mammals. This project also will replant the riparian zone of the river with a mix old growth tree species (both deciduous and coniferous) and pollinator shrubs/native flowers. These plantings will reestablish a lush riparian canopy, help cool the water as trees mature and provide large wood debris in the stream as the trees die and fall into the river. DNR shocking data and future returns to the weir will measure the improvement in the fishery
MN DNR, Private Source: LSSA and Private Source: ZG and LSSA
Street, Duluth, MN. 55802 P. O. Box 16034, Duluth, MN. 55816