Phase one results of Lincoln County Stream Crossing Inventory now available

LINCOLN COUNTY – In the spring of 2025, Lincoln County’s Land Services Department initiated a project to assess culvert stream crossings on public roadways throughout the County. The objective of this project is to evaluate culverts based on their current condition and environmental impact.

Using this information, crossings are then prioritized for replacement. The findings of this project are ultimately shared with the municipalities responsible for the maintenance and replacement of these structures. That information will allow road managers to plan for culvert replacements, determine the correct size and placement of those structures and provide avenues for various forms of financial aid.

It has been determined that three project phases will be necessary to assess all the culvert crossings in Lincoln County. Using the Wisconsin Department of Natural Resources (DNR)'s Surface Water Data Viewer (SWDV), 573 crossings have been identified for assessment. The Land Services Department received a Surface Water Grant from the DNR to complete phase one, which assessed over 200 crossings in the Townships of Birch, Harrison, King, Merrill, Pine River, Russell, Schley and Skanawan.

Crossings are assessed and prioritized using the Great Lakes Stream Crossing Inventory protocols, which consider factors such as stream constriction, erosion, fish passability and the condition of the culverts. This data helps to identify the culverts in most need of replacement or repair.

Results from phase one show that significant stream crossing improvements could be made throughout our road system. Passability results show that of the 209 assessed crossings, 86% were a barrier or had the potential to be a barrier at certain flows for fish and other aquatic organisms. Improperly placed culverts are often perched or set incorrectly, leading to velocity barriers, depth issues or ponding issues that impede fish passage. Only 11% of assessed crossings were determined not to be a barrier.

Additional insights for phase one include: 54% of assessed crossings were determined to be undersized; 90% of crossings did not meet the buried depth standards; 28% of crossings were exhibiting major to severe deterioration; and 25 crossings were experiencing significant erosion (two tons/year or more).

Representatives from local municipalities were invited by the Land Services Department to participate in a workshop to discuss the results of phase one. Beyond discussing the phase one results, attendees heard from professionals with Trout Unlimited, Wisconsin’s Department of Agriculture, Trade and Consumer Protection (DATCP) and the DNR, which all offered insight on proper culvert placement, construction practices and potential cost-sharing opportunities.

A final report detailing the findings from phase one is now available on the Lincoln County website at www.tinyurl.com/3xfwjr3z.

For more information on this project, contact Tom Boisvert, Conservation Program Manager, at 715-539-1054 or via email at thomas.boisvert@co.lincoln.co.wi.