The soils in approximately one third of Bayfield County are characterized as highly erodible calcareous red clay. Nearly all of those soils are located in the Lake Superior watershed, along with a range of soils from deep glacial outwash composed of sands to silt loams. Timber harvesting, a major part of the county's economy, has a significant impact on these soils. Poor forestry practices, including poor forest road construction and poorly designed or inadequate stream crossings, are a major source of silt eroding into area streams. Background Slightly less than 800 square miles of Bayfield County drains into Lake Superior, with forested lands making up the majority of that land area.
Timber harvesting is a major part of the county's economy.
Logging practices often impact these water resources, and poor practices have historically been a significant contributor to nonpoint source pollution problems and water quality degradation in the Lake Superior basin. The goal of this project was to demonstrate the feasibility of using portable timber bridges for temporary stream crossings for timber harvesting equipment in order to reduce nonpoint source pollution in the Lake Superior watershed. Portable bridges have not been widely used in the region, therefore this is an opportunity to provide information about the cost and sources of portable bridges as well as to encourage their use. The advantages of this type of crossing are that it requires no in-stream construction or fill material placed in the channel, there is a low potential for introduction of sediment into the waterways, fish movement is not restricted, and there is minimal resistance to flood waters. Portable bridges may also assist logging contractors or other forest users that require temporary water crossings to access woodlands in an efficient, cost-effective, and less damaging manner.