Knife River Habitat Rehabilitation Phase II
$1,410,000 in the second year is to the commissioner of natural resources for an agreement with the Lake Superior Steelhead Association to enhance trout habitat in the Knife River watershed. A list of proposed enhancements must be provided as part of the required accomplishment plan.
Increased availability and improved condition of riparian forests and other habitat corridors - This project will enhance the lost riparian zone..Healthy populations of endangered, threatened, and special concern species as well as more common species - This project should increase the native naturally reproducing brook, brown and steelhead populations in the Knife River..Greater public access for wildlife and outdoors-related recreation - This project should increase the overall trout population and give anglers more areas to fish and provide better opportunities to catch more fish..Improved availability and improved condition of habitats that have experienced substantial decline - This project will improve stream habitat for brook, brown and steelhead trout..Improved aquatic habitat indicators - This project will improve in-stream habitat by installing large woody debris that was lost due to logging of old growth trees..This project will retain water through increased transpiration via tree planting and reduce erosion through streambank stabilization. .
Degradation to trout habitat in the Knife River Watershed has occurred from past clear-cut forestry practices resulting in uncontrolled beaver colonization. This project will continue work on the West Branch and begin work on other Knife River tributaries.
The Knife River once held one of the largest populations of natural reproducing steelhead in the Great Lakes and provided spawning habitat in its upper watershed to thousands of steelhead each spring. Since the late 1970’s, the Knife River steelhead population has seen a dramatic decrease. Once thousands of steelhead traveled upstream to spawn, now on average five hundred make this same journey. One of the primary reasons for the decrease in the Knife River’s steelhead population is the degradation to the upper Knife River watershed riparian habitat.
Habitat Degradation and its Results to the Upper Knife River Watershed
The historic forest composition within the Knife River watershed was old growth coniferous trees. Extensive clear-cut logging removed the old growth coniferous trees throughout the Knife River watershed and were replaced by large stands of second growth aspen. This large-scale forest alteration attracted unprecedented beaver populations to the watershed because of the new food source. Once beavers colonized this area, dams were built blocking the stream flow and flooding the riparian tree cover. The flooded trees and shrubs along the riparian zone quickly died resulting in open water ponds. The impoundment of shallow water and lack of tree cover associated with the beaver pond caused the water temperature to quickly warm and has led to an increase in evaporation. This increase in beaver activity has resulted in 30 plus years of habitat degradation to the upper Knife River watershed.
DNR Habitat Work and Studies Conducted in the Upper Knife River Watershed
Recognizing the threat to the upper river, the DNR started performing limited stream studies. These studies have determined that habitat degradation to the upper watershed has resulted in poor rearing conditions for juvenile trout during the summer months. These poor rearing conditions (increase in water temperature, increase in evaporation and decrease in stream flows) are the direct result of beaver activity/habitat degradation in the Knife River watershed.
The LSSA proposes to use existing aerial data to locate and assess the beaver impacted areas on the upper Knife River and its tributaries. The LSSA will discuss and rank the locations for rehabilitation. The area of focus will be spawning tributaries within the Knife River watershed, which include the upper Main Knife River, West Branch, Stanley Creek, McCarthy Creek, Little West Branch, Captain Jacobson, Little Knife River, Little East Branch and Unnamed Tributaries of the Knife River. Only stream sections located on public lands and private lands with DNR easements will be considered for this project. There will not be any work performed on any private land unless a DNR easement is currently in place with an accompanying Stewardship Plan.
A field reconnaissance will be conducted to determine the stream’s condition and to design the rehabilitation project. The assessment data that will be collected may include:
Review aerial photo and GIS maps of beaver impacted areas.
Mark GPS location of habitat degradation.
Determine proximity to access points.
Measure the area of impacted stream.
Survey the depth of sediment deposition.
Determine length and thickness of remnant dam(s).
Survey the stream elevations.
Quantify the amount of large and small woody debris.
Calculate the percent of shade covering various stream sections.
Monitor water temperature.
Monitor stream flow.
Document evidence of juvenile fish through shocking and adult spawning activity visually.
Identify collapsed banks or erosion areas.
Construct cross-section diagrams.
Evaluate fish passage and connectivity.
The assessment will enable the LSSA to design the rehabilitation construction/tree planting projects. A draft of the proposed stream rehabilitation project design will be provided to project stakeholders and DNR Fisheries for input on the project.
Remove in-stream beaver dams and silt deposits, collapsed stream banks and woody debris that inhibit fish migration and negatively alter stream flow.
Planting of trees to enhance the overhead canopy.
Removal of invasive vegetation.
Enhance stream flow connectivity.
Placement of large woody debris.
Removal of small woody debris.
Repair or stabilize eroded stream banks.
The project data and design parameters will be incorporated in a project permit and submitted for approval to the DNR and Army Corp. of Engineers.
Equipment Usage and Project Site Access
The goal of this project is to restore beaver impacted areas within the upper Knife River watershed. To accomplish this goal, mechanical equipment may be used in specified areas that have vehicle access or in logged areas. In areas with vehicle access to the watershed, heavy equipment may be mobilized to remove dams, stabilize stream banks, placement of large woody debris and plant mature trees. These areas will be given a high priority because rehabilitating these stream sections can provide an almost immediate benefit to the watershed.
Tree planting will be a critical component of this restoration project. Tree planting will be focused on the riparian area of the stream or watershed. In remote areas of the watershed tree planting may be the only reasonable method of restoration employed due to lack of access. Plantings will vary between coniferous and deciduous trees and shrubs. The proposed species will consist of a various arrangement of bare root, potted and large root bundled trees. Some of the tree species that may be utilized include: spruce, tamarack, red pine, silver maple, alder, swamp oak, river birch and red maple. Tree species due to Climate Assisted Migration will also be evaluated.
Black Ash Stand Identification
Black ash stands currently comprise a large percentage of the riparian forest community in various sections of the Knife River watershed, most notably in the headwaters where young trout rear. The State of Minnesota and the Minnesota DNR expect that all ash stands in the state to eventually experience high to total mortality due to an infestation of the emerald ash borer. This project aims to attempt to identify and retain shade cover for the upper Knife River watershed by identifying black ash stands and planting additional tree species within the riparian corridor to diversify the forest. Forest comprised primarily of black ash will be targeted for this component of the project.