With funding from the Region 3 Fish Passage Program, the Ashland National Fish & Wildlife Conservation Office (NFWCO) and its partners completed a culvert replacement on Wildcat Creek, which crosses Ashland-Bayfield County Line Road in the Town of Lincoln, Ashland County, WI, and flows into the Marengo River.

This area is part of the Bad River Watershed, the largest watershed on the southern shoreline of Lake Superior.  Native fish species such as brook trout, sculpin and redhorse species inhabit Wildcat Creek, along with naturalized brown and rainbow trout, and the creek provides spawning and nursery habitat for introduced coho salmon.  After a flood in the area in the late 1980s, the town replaced the culvert but unfortunately, it was not properly placed.  The upstream side was lower than slope needed, causing pooling above, and subsequent rain events ended up creating a perched culvert on the lower end. 

Ashland NFWCO purchased the new 6' x 60' culvert, and the Town of Lincoln supplied manpower and funding to hire the Ashland County Highway Department to supply a large excavator for the construction work.  Ashland NFWCO and the Ashland County Land Conservation Department (ACLCD) conducted a pre-construction survey for the correct placement of the culvert.  Plans for the culvert replacement were engineered by the ACLCD with assistance from the Natural Resources Conservation Service.

Construction started on August 21 and was completed on August 22.  The crew set up a 5" gas powered trash pump and a earthen dam was constructed above culvert.  The stream was diverted around the construction site and the road removal to uncover the culvert began.  A smaller diaphragm pump was used to lower the plunge pool below the culvert and all fish that were trapped in this pool were recovered and moved to the stream.  The old culvert was removed, the stream bed shaped to the proper depth and slope, and the new culvert was set in place. 

By the end of the first day the culvert was set and covered, and the road opened for traffic.  The earthen dam was also slowly opened to allow the stream to flow once again and deposit substrate into the culvert. 

Final touches to the stream banks and seeding/mulching of the site occurred the second day.  By the time the crew returned the morning of the second day the creek had head cut down approximately 2 feet to the old stream bed, exposing gravel beds and large woody debris that had lined the stream bank, and traveled 75 yards upstream.  Several small trout were observed swimming out of the culvert and heading upstream during the final touches to the area.

Ashland NFWCO also conducted a pre- and post- construction fish survey to assess the culvert replacement.  The pre-construction survey was conducted on August 17, 2007, with assistance from interns Abby Purdy and Ryan Huber, UW-Stevens Point students, working at the Northern Aquaculture Demonstration Facility, Red Cliff, WI. A segment of creek below the culvert was surveyed with a backpack electrofishing unit and all trout species were collected. 

In this stretch 176 trout were captured, 86 brown trout, 50 brook trout and 40 rainbow trout.  All fish received a lower caudal clip, and were measured and released.  A segment above the culvert was also shocked, with a total of 64 trout captured, 37 browns and 27 brookies.  These fish received a upper caudal clip, were measured and released. 

The recapture run was conducted on October 11.  Assistance was provided by Dr. Derek Ogle's Fisheries Science and Management Class at Northland College, Ashland, WI.   The same segments below and above the culvert were electrofished and all trout species were collected.  Below the culvert a total of 68 fish were captured, 47 of them brown trout, with five of these having the lower caudal clip (LC), five rainbow trout, with no recaptures and 16 brook trout, with two LC recaptures. 

Above the culvert a total of five trout, three browns and two rainbows, were caught.  Two of the brown trout were clipped, one with a lower caudal clip and the other a upper caudal clip.  It appears that the culvert is allowing fish passage and the inhabitants of Wildcat Creek are able to assess the upper reaches of Wildcat Creek.