DNR Aquatic Habitat Restoration and Enhancement - Phase 4
Diverse habitat is critical to sustaining quality fish populations in lakes and rivers. The Minnesota Department of Natural Resources (MNDNR) will complete six fish passage projects to restore habitat connectivity for fish and other aquatic life, and restore reaches of four different rivers, creating 24.4 miles of diverse aquatic habitat. Though the actual footprint of fish passage projects is relatively small, these projects will reconnect over 27,000 acres of lake and river habitat. Stream projects were selected from a statewide list, prioritized by factors such as ecological benefit, scale of impact, urgency of completion, and local support.
The Minnesota Department of Natural Resources (MNDNR) annually updates a statewide list of stream habitat projects. Project submittals come both from MNDNR staff and from partner organizations. Projects are prioritized based on scale-of-impact, urgency, local support, and critical habitat for rare species. Based on this list, MNDNR and our partners are proposing six fish passage projects and four channel restorations, leveraging a confirmed $3,225,000 and an additional $980,000 requested from other sources.
Access to diverse habitats is critical for fish and other aquatic organisms to complete various life stages. The habitats they use at different life stages may all vary widely. These habitats can be fairly unique, such as high-gradient riffles favored by many spawning fish, and may be miles apart. When dams or other obstructions prevent aquatic life from reaching ideal habitat, they are forced to use less optimal locations that can reduce their success. In some cases this leads to the complete loss of sensitive species upstream of a barrier. Research by MNDNR River Ecologist Luther Aadland found that on average, species richness declined by 37% upstream of near complete barriers to fish passage. Subsequent removal of 11 barriers in this study resulted in upstream recolonization of an average of 66% of the species that had been absent.
Modifying or removing the barriers through our two proposed fish passage projects would have a total footprint of 6 acres, but create upstream access to over 27,000 acres of lake and river habitat. This will benefit fish such as Walleye and Brook Trout present in these rivers, as well as five mussel species classified as threatened or special concern. Restoring connectivity also expands fishing opportunities by acting as a conduit for recolonization should something catastrophic such as drought happen in one portion of a watershed.
Streams naturally form habitat through the meandering of the river. Deeper, slower habitat is created by scour into the bed of the river around the outside of bends, while faster water and a rockier bottom is found in the straight sections in between. Wood, overhanging vegetation, and boulders serve as cover and current breaks for fish. In degraded sections of river, these natural processes are disrupted. Some reaches have been artificially straightened, preventing the meandering that forms diverse habitat. In other places, streams have become surrounded by tall banks that prevent high flows from spilling out onto a floodplain. When floods are trapped within the stream channel, the river erodes the banks. This not only mobilizes tons of sediment that degrades downstream habitat, but results in a wide, shallow channel during low-flow periods that is avoided by adult fish. Channel restoration projects will utilize reference locations with high-quality habitat to improve habitat. Working with partners, we will restore 24.4 miles of habitat on four streams.
$2,790,000 the first year is to the commissioner of natural resources to restore and enhance aquatic habitat in degraded streams and aquatic management areas and to facilitate fish passage. A list of proposed land restorations and enhancements must be provided as part of the required accomplishment plan.
Improved aquatic habitat indicators - For the Kingsbury Creek project, we will evaluate instream habitat as well as brook trout populations to assess success. For the Grindstone Dam project, we will use routine fish surveys to gauge changes to the fish community and compare to pre-project data.
Rivers and streams provide corridors of habitat including intact areas of forest cover in the east and large wetland/upland complexes in the west - Both MNDNR and PCA conduct periodic surveys of the Otter Tail River watershed. For the Otter Tail Lakes Dams project, we will compare warmwater fish communities before and after project completion. We will also compare catch rates for critical species before and after project completion as indicators of population density changes.
Improved aquatic habitat indicators - For the Beven's Creek dam project, we will use routine fish surveys to gauge changes to the fish community, and compare with pre-project data.
Rivers, streams, and surrounding vegetation provide corridors of habitat - We will evaluate instream and riparian habitat measures to evaluate the success of the North Branch Whitewater River restoration. Changes in fish populations will also be evaluated.
The Whiskey Creek channel restoration project in this region will improve in-channel and riparian habitat. We will use metrics that evaluate instream and floodplain habitat to assess our success
NRCS, EPA, BWSR and Carver County WMO