Cold-water stream systems
are virtually the only areas where brook trout can survive and thrive. This sensitive habitat is becoming increasingly scarce in eastern Minnesota and northwestern Wisconsin, due to beaver dams, development, loss of shoreline shade trees, and other land-use changes. Brook trout are intolerant of warm water and will either abandon warm streams or perish.
To reverse the trend of habitat loss in the streams that drain into the Riverway, the National Park Service has launched a new initiative with the Wisconsin Department of Natural Resources (WDNR), the Minnesota Department of Natural Resources (MDNR), and the Great Lakes Indian Fish and Wildlife Commission.
One specific project is focused on restoring Cap Creek, a tributary to the Namekagon River near Cable, Wisconsin. Historic accounts indicate the stream provided an excellent brook trout fishing experience. Springs in the lower section of the stream provided cold, high quality water. In the early 1950's, the landowner routed Cap Creek into a new channelized stream course, and excavated ponds surrounding the springs to make rearing ponds for rainbow trout. The rainbow trout were raised for local restaurants and for anglers interested in catching trout.
In the 1980s the National Park Service purchased the trout hatchery and surrounding land as part of the long-term program to protect the scenic qualities of the Namekagon and St. Croix Rivers. The buildings associated with the hatchery were removed, as were the water level and outlet control structures on the rearing ponds. The ponds themselves were retained, although with shallower water levels. Visitors to the site are able to see springs that seem to boil from the sand as the groundwater bubbles into the ponds. Because of the shape of the ponds, however, the scene does not look very natural.
Currently, the ponds harbor very little aquatic life. The shallow water offers no cover for fish to escape predators, and the bottom substrate is a homogenous mix of sand and silt providing very limited habitat for aquatic insects. The ponds have been described as "biological deserts" because of their limited biodiversity.
In 2001, the WDNR and the National Park Service began to discuss a restoration project for the lower segment of Cap Creek. Habitat engineers from WDNR surveyed the site and came up with designs for restoring Cap Creek to its original location. Components of the project include filling some of the ponds that are marginal wetlands, protecting the springs by incorporating them into the restored stream course, and stocking the new stream segment with native brook trout captured elsewhere in the Namekagon River watershed.
The project has gone through extensive review within the National Park Service and the WDNR. Wetlands and stream channel permits were received from the U.S. Army Corps of Engineers and the WDNR. The project was analyzed for its potential environmental impacts as required by the National Environmental Policy Act. Strict adherence to erosion and sediment control will be a critical part of the project. Re-vegetation of the stream banks and adjoining lands will be done using native vegetation. The project will be completed in 2003.