Rum River Wildlife and Fish Habitat Enhancement using Bioengineered Bank Stabilization

Eighty sites spanning seven miles of actively eroding riverbank were identified along the Rum River in Anoka County, an Outstanding Resource Value Water and Wild, Scenic and Recreational River. Identified bank failures contribute an estimated 7,838 tons of sediment to the river annually, which decimates littoral transitional habitat, smothers fish spawning areas, compromises mussel reproduction and vigor, and reduces success of predatory game fish species due to increased turbidity. The Anoka Conservation District (ACD), along with Anoka County and landowners, proposes to systematically stabilize and enhance these damaged riverbanks. In total this undertaking will require a projected $14 million in public and private funds, drawing upon several grant funding sources, and spanning multiple grant cycles.
An inventory of active erosion sites was finalized in March of 2019 by ACD (https://www.anokaswcd.org/images/AnokaSWCD/Reports/Inventory/Rum_River_…). Based on erosion severity, sites were assigned one of three stabilization approaches, which align with one of three state funding sources. Seventeen tall, severely eroding riverbanks require armament, have a primary benefit of water quality improvement, and will be addressed with CWF funding. Twenty-one shorter, moderately eroding riverbanks can be corrected utilizing bioengineering approaches, have a primary benefit of habitat enhancement, and will be addressed with LSOHC funds. Forty-two short, moderately eroding riverbanks can be corrected utilizing cedar tree revetments and will be addressed with CPL funds.
This grant request is for ACD, in partnership with Anoka County, to enhance three to seven sites over three years that can be addressed using bioengineering approaches such as bendway weirs and root wads that produce in-stream habitat for fish, turtles and amphibians, native plantings and staking that produce riparian habitat above the water, and light toe armoring and minor grading that make these habitats traversable by wildlife. Sites will be prioritized considering linear feet of habitat enhanced, cost-benefit analysis, landowner buy-in, and accessibility. Phase-1 projects will enhance up to 2,250 feet of habitat, and reduce sediment loads to the Rum River by up to 630 tons/year.
Riverbank stabilization design and installation processes can present hazards to some wildlife; namely nearshore mussels, amphibians and reptiles during construction, and reptiles and amphibians that are unable to safely traverse the post-construction stabilization materials and plantings. As part of this project, ACD intends work with experts in the field to conceptualize, design and implement approaches to best abate these hazards, with particular attention on species in greatest conservation need (SGCN) such as state-listed mussels and Blanding's turtles.
The Rum River is identified as a key river stretch for habitat and species richness for SGCN through Anoka County. Large portions of critical streambank transitional habitat that these species depend on are gone already, with more lost each year. The number of optimal sites for habitat enhancing bioengineering approaches is limited, and will continue to diminish if left unchecked. Inventory work by ACD shed light on the severity of the issue and the scale of the opportunity to take corrective action.