Culvert Restoration Program

Culvert Restoration Program

The Bad River watershed is the largest basin on the south shore of Lake Superior. Fish passage and sedimentation at road stream crossings have been identified as major concerns in the watershed. To address this concern, the Bad River Watershed Association (BRWA) initiated the Culvert Restoration Program in 2004 to conduct a watershed wide, quantitative road-stream crossing inventory and identify specific sites that are priorities for remediation. Now SRWA continues this project.

When roads were first built in the region, we focused on getting cars and trucks across the stream.  We didn’t consider the potential negative effects that crossings can have on our streams and fish.  With over 1,000 road stream crossings in the region, the effects of these crossings on our streams and fish can be significant.

Culverts act as barriers to fish by blocking access to quality habitat upstream.  For instance, there may be a drop at the outlet that prevents fish from getting into the pipe, or the water may be flowing too fast for fish, especially smaller ones, to make it all the way through a pipe.  Road crossings can also have a negative effect by adding sediments into our stream channels when there is a road failure or a regular eroded stream crossing.  The extra sediments can cover the stream bottom, smother insects which are the food for fish, and limit spawning success.

SRWA’s Culvert Restoration Program aims to:

  • Educate citizens about the environmental and fiscal costs of improperly designed and/or installed culverts
  • Identify and inventory all road/stream crossings
  • Prioritize crossings in need of repair with respect to fish passage barriers and sedimentation
  • Search for funding to help pay for new installations

The Culvert Restoration Program is successful due to a collaborative partnership of local governments and agencies.  Key partners of the program in addition to SRWA are the US Fish and Wildlife Service, Wisconsin DNR, Ashland County, Iron County, Bayfield County, local town officials and road crews, and streamside landowners.

Site Selection

Two sets of criteria are used to judge which sites become prioritized. One measures stream habitat, the other measures the road-stream crossing condition.

Culverts are prioritized according to the quality and quantity of habitat that their remediation can provide.  Other factors that determine which sites are selected include the condition of the pipe, erosion around the pipe, sedimentation and flooding or road wash out.  Generally the culverts that have the most priority in replacement are those that are closest to Lake Superior and house a migratory fish population.

Another consideration that plays a key role is how much stream the replacement opens up.  If a culvert is the only culvert on a 2 mile stretch and is an inadequate fish passage, by replacing it you open up 2 more miles that had not been available previously.  However, if another culvert is just down the stream by a ¼ mile then it will not open up nearly as much water.

A few culverts are what is termed “first impassable barriers” meaning that is the first spot in the river that migrating fish cannot get past.  Culverts of this nature also receive priority because any culvert beyond this culvert will not benefit fish migration without first replacing the “first impassable barrier”.

Site selection is a process that is carried out to efficiently utilize resources in our watershed.  This means coordinating with local, county, state and even federal agencies to see that SRWA dollars are spent on culverts that would not have already been fixed by one of these agencies.  After a list of priority sites is assembled by SRWA, stakeholders decide annually which sites will be funded for remediation.  The same basic sets of criteria are used in these decisions.  Although certain grants such as the USFWS coastal program can only be allocated towards opening or improving sites that connect directly with Lake Superior. Certain sites may also be priorities on the agendas of other agencies.

For more information on the Culvert Restoration Program please contact Kevin Brewster, Watershed Restoration Manager, at 715-682-2003 or info@superiorrivers.org