Knife River Habitat Rehabilitation-PH VII
Historic flooding led to severe habitat degradation throughout the Knife River watershed. Including miles of slumping streambanks, thousands of tons of sediment discharge, turbidity measurements exceeding the MPCA's TMDL and loss of instream trout habitat. DNR has documented a 200% increase in adult steelhead population, two miles of restored stream channel, 10,000 feet of stabilized streambanks and annual reduction of sediment discharge by 1,000 tons due to our projects. This seventh project will stabilize over 4,500 feet of slumping streambanks and improve both riparian and instream habitats.
The LSSA uses a Watershed Restoration Approach to determine the rehabilitation, enhancement and restoration scope of work. This Approach looks at how landscape parameters affect the river's stability and identifies what the underlying issues are that cause the watershed impacts during a flood event. Habitat rehabilitation projects utilize Natural Channel Design (NCD) parameters. By focusing on the Watershed as a whole and working to fix the root cause, the stream and the immediate riparian zones are much healthier and robust for decades to come, benefitting all trout populations and instream invertebrates.
Our Knife River rehabilitation success has not just restored the watershed parameters but has also translated to an increase in the adult steelhead. From 2012 (the inception of our first grant) to 2021 the population of wild steelhead has increased in the Knife River by 200%. This 200% increase has occurred at a time, when other notable Lake Superior tributaries have observed steelhead populations decrease or crash. Two of the most prominent Lake Superior tributaries the Brule River and Portage Creek both saw their adult steelhead returns noticeably decline. The Brule River steelhead population decreased 4.5% from its 30 year average and Portage Creek steelhead population decreased 201% from its 20 year average.
Another feature we utilize on every rehabilitation project, is a prioritization system to identify specific restoration reaches. Our policy is to work from an upstream to downstream manner. This top-down restoration approach eliminates re-impacting previously restored stream sections and reduces downstream flooding and sedimentation because water and sediments are deposited and held on the newly constructed upstream floodplains. Our reach prioritization also utilizes existing agency studies, such as the MPCA's TMDL to identify erosion areas. These erosion areas are combined with our cool water temperature assessments and annual trout spawning survey to ensure we restore the most critical stream reaches.
Finally, we engage Stakeholders in the final reach selection process. The LSSA has collaborated with the DNR for eleven years to identify key trout habitat sites within the Knife River watershed and discuss key sites proposed for restoration. By utilizing this prioritization approach, we ultimately invest grant funds in the most efficient manner possible.
NOTE: The Arrowhead Regional Development Commission (ARDC) has agreed to work with the LSSA as fiscal manager going forward. Please see note in ATTACHMENTS.
The Scope of Work for the Reach 15 project will include:
-Assess, survey and design the stream reach(s) to obtain permits.
-Obtain baseline and as-built assessment and survey data.
-Restore the stream channel's shape, dimension and profile.
-Enhance riparian and instream trout habitat.
-Create new floodplain wetlands.
-Reconnect the river channel to the floodplain.
-Raise the groundwater table.
-Stabilize streambanks.
-Rehabilitate the riparian tree canopy.
-Monitor water temperature.
$1,572,000 the second year is to the commissioner of natural resources for an agreement with the Arrowhead Regional Development Commission, in cooperation with the Lake Superior Steelhead Association, to restore and enhance trout habitat in the Knife River watershed. If the Arrowhead Regional Development Commission declines to serve as the fiscal agent for the project, an alternative fiscal agent must be identified in the accomplishment plan for the project.
Healthy populations of endangered, threatened, and special concern species as well as more common species - By funding this project, anadromous trout (steelhead, coaster brook trout and brown trout) and resident stream trout (brook trout) populations should increase. Population increases will be seen by MNDNR during the weir operation and upstream population assessment work. This project will also provide habitat to invertebrates, amphibians, reptiles, birds and mammals. This project also will replant the riparian zone of the river with native, old growth tree species and various native shrubs and native pollinator flower species. These multiple specie plantings will establish a varied and lush riparian zone benefitting the entire watershed and neighboring areas for decades to come
DNR, Private, Private, LSSA, Private, LSSA Volunteer and Private-Other