PROJECT SUMMARY

The Koochiching Soil and Water Conservation District (KSWCD), in partnership with the Rainy Lake Property Owners Association (RLPOA), sought funding to restore nine (9) acres of wetlands on Rainy Lake, MN at the juncture of Koochiching County Road 134 (CR 134) and Elks Bay. The site has been significantly impaired by the infestation and dominance of non-native hybrid cattails. The infestation has been accelerated by loss of natural water flow from past road construction and a legacy of privately owned septic systems that were poorly suited to the soil conditions. The consequence has been the displacement of native aquatic plant species, degradation of habitat for waterfowl and fish, and the creation of floating navigational hazards.

Restoration of this 9-acre wetland will remove floating mats of invasive hybrid cattail, enhance natural aquatic habitat, and re-establish a more natural water flow. Left unchecked, non-native hybrid cattails will continue to dominate and spread through the area.

The proposed project comprises three main activities. To enhance water flow, an existing 48-inch circular culvert will be replaced by a 16’ x 10’ box culvert with the raising and widening of the roadway above the 2022 flood level. Next, utilizing methods tested at Voyageurs National Park, nine acres of hybrid cattails will be removed utilizing a combination of prescribed burning above ice during frozen lake conditions followed by mechanical removal of the remaining biomass during open water. Finally, approximately 2 acres of the restored area will be seeded with native aquatic vegetation and, if viable, wild rice.

PROBLEM STATEMENT

Shoreline access and habitat for native wildlife and vegetation on Rainy Lake have suffered in recent decades due to an overgrowth of non-native hybrid cattails. This project addresses environmental and ecological impairments on a nine-acre site located at CR 134 and Elks Bay. This site was largely open water prior to the emergence of hybrid cattails starting around 1980. Construction of CR 94, 134, and 135 to provide road access to islands did not consider openings for natural water flow. And until the creation of the East Sewer Sanitary District, private septic systems which were poorly suited to rocky shorelines added substantial nutrient loads into these waters. The loss of water flow, trapped nutrients, and loss of wave action accelerated the encroachment of hybrid cattails, ultimately resulting in an extensive, dense monoculture degrading the waterways adjacent to CR 94, 134, and 135 and the islands they connect.

Non-native hybrid cattails grow taller, faster and more densely than the native species that they out compete and displace. Dense stands of hybrid cattails block sunlight and reduce dissolved oxygen which makes poor habitat for fish spawning. The dense hybrid monoculture also provides poor habitat for predator fish like northern pike, poor cover for marsh waterbirds, poor nesting sites for waterfowl, and is a poor source of nutrition for wildlife. This project incorporates lessons learned from a similar project in the same area. In 2007, a 12-foot wide box culvert was placed under CR 94 allowing water to flow north out of Jackfish Bay. A channel to the culvert was dredged through dense cattails. Subsequent aerial imagery shows the channel widened significantly and cattails regressed as floating mats broke away. Unfortunately, these mats create floating navigational hazards, landing in and potentially infesting other parts of the lake including Voyageurs National Park. The 2007 project demonstrated the importance of enhanced water flow for sustainable cattail reduction but also created troublesome floating cattail bogs. This project proposes an integrated approach where cattails are initially removed to avoid the release of floating mat fragments and then creates a more sustainable native environment by enhancing water flow and seeding native species.

PROJECT OBJECTIVES

The project site includes the roadway of CR 134 where it crosses Elk Bay, and 9 acres of lake waters to the east and west of  CR 134, currently overgrown with dense mats of hybrid cattails. Three project objectives have been identified for this site which, collectively, will help restore and sustain a habitat for aquatic plants and wildlife native to the region.

Enhancing water flow beneath CR 134 is essential to sustain a native habitat. The limited water flow beneath CR 134 currently traps nutrients and blocks the effects of current and wave action. An existing 48-inch culvert will be replaced with a 16’x10’ box culvert, similar to what was done on CR 94. The culvert will significantly improve water flow, exposing a six to ten-fold increase in cross section for water flow.

A contractor will be hired to install 16’x10’ box culvert. The roadway will be raised and widen to accommodate the culvert, and to raise it above the 2022 flood level. The placement of a 12 culvert through CR 94 in 2007, which created water flow out of Jackfish Bay to the north, resulted in regression of cattails on either side of the culvert.   It also led to the creation of many floating bogs. We were encouraged by the result that restoring water flow led to the localized regression of cattails but were concerned that restoring water flow through the other county roads in the area without cattail removal would create more floating bogs. Without removing the non-native hybrid cattails initially, there would be little hope of restoring native plants or improving habitat for fish and wildlife.

OBJECTIVE PURPOSE: 

• Remove trapped nutrients which favor hybrid cattail growth
• Restore waterflow
• Promote regression of non-native hybrid cattails
• Accommodate new box culvert
• Provide Flood Mitigation

TIMELINE / TASKS

• Summer/Fall 2024
  
  • Replace existing 48”culvert culvert with 10’ X 16’ box culvert
  • Raise elevation of CR134 by approximately 4 ½ feet
  • Construct bypass for continued access during construction

In February 2024 the International Falls volunteer fire department attempted a prescribed fire on the remaining cattails. Despite little to no snow cover and good wind conditions during the burn, the material did not burn well.

In March, Koochiching SWCD (KSWCD) started receiving letters from concerned landowners in the east bay area where cattails were cut in 2023. Silt that was once locked in the roots of the cattails had formed large clumps over winter. KSWCD staff were in contact with Lakes Aquatic Weed Removal (LAWR) coordinating plans once water levels became deep enough for the equipment and road weight limits were off to address these concerns and complete the remainder of the project.

Before LAWR arrived on site, a meeting was held on County Road 134 between the two bays to hear property owners’ concerns. On May 13th, LAWR arrived on site and began mobilizing equipment. Cattail material was removed from the previous year’s cutting that had formed clumps. Once the material had been collected from the east bay (Jackfish Bay), LAWR began cutting and collecting the remaining material on the west bay. Heavy rains from late spring to early summer created problems for hauling the material to the transfer station. The access road to the dump site became rutted, forcing LAWR and KSWCD to find secondary disposal sites. Several landowners agreed to allow the last of the loads to be hauled to their upland sites before upcoming road work was to be completed on County Road 134. All disposal sites were pre-approved by the County and Board of Water and Soil Resources.

A Rainy Lake Property Owners Association member used equipment borrowed from Voyageurs National Park to hand cut cattails along the Northern portion of Jackfish Bay where it was too shallow for LAWR to cut. KSWCD staff used modified rakes to pull the cattails above the ordinary high-water mark and to move and break up floating silt mats to areas that wouldn’t interfere with recreation. This was a difficult and slow process due to the size and weight of the clumps and only provided results for a few weeks before the wind blew new clumps in.

Road work began in August to raise and widen County Road 134. The Koochiching County Highway Department led the road project and was able to remove the cattail material that had collected near the roadway edges between the east and west bays. County Road 134 remained open through most of this portion of the project and allowed KSWCD to frequently monitor the bays. KSWCD staff also completed multiple native plantings after water levels dropped, allowing seeds to grab hold of the land before the water rises again, as they tend to float.

Couchiching First Nations Lands and Resources Coordinator was contacted in July to procure wild rice that was native to Rainy Lake. Unfortunately, KSWCD staff were notified in September that the wild rice crop was poor and there would be none to spare for the project. Other wild rice seed sources on the U.S. side were checked through various agencies but the poor crop issue was state-wide.

Plans remain in place to seed wild rice in 2025 and clay has already been placed at the access to make clay balls, which assist with seeding.

The final phase will be to restore native vegetation, including wild rice, to inhibit the return of non-native hybrid species and create a more resilient native aquatic habitat. Two acres of the site appear well suited for native aquatic vegetation. A seed list of 26 species native to Koochiching County, courtesy of Minnesota Wildflowers, has been assembled with the advice of Minnesota Native Landscapes. Wild rice seeding will be attempted following best practices recommended by Voyageurs National Park and Treaty #3 Communities which have successfully re-established significant wild rice growth within First Nation Communities on Rainy Lake.

Two acres in the project area will be seeded with a custom wetland seed mix, developed in collaboration with Minnesota Native Landscapes, containing 26 species which are native to Koochiching County. A similar seed mix was utilized by Voyageurs National Park following a hybrid cattail removal project. With guidance from Treaty #3 Community leaders, VNP, and MN DNR, 1 to 2 acres will also be seeded with native wild rice seed. If the guidance reveals that wild rice is not well suited to our project site, sedges and bulrush will be seeded instead.