Otter Creek Project Summary

The Otter Creek project began in 2006, with meetings and studies conducted to look at flooding problems along Otter Creek. After many studies, it was determined that none of the options presented would significantly reduce flooding along Otter Creek's banks. The watershed is extremely "upside-down" in its shape, with the widest part of the watershed at the top and becoming narrower as it drains down toward the Wisconsin River. This unique shape adds to the flooding problems that seem to occur on a yearly basis. The studies looked at a number of possible solutions for flood mitigation including building several small dams to hold back storm water in the upper watershed; road impact along Highway C; modifying drainage from the Badger area to reduce flow; removal of debris dams along the channel in Otter Creek; and the construction of a concrete channel at the lower end to drain into the Wisconsin River. The engineering analysis for these proposals lowered flooding levels.

During 2007, hydrologic and hydraulic studies were investigated by the USDA-Natural Resources Conservation Service (NRCS). The NRCS engineering staff spent extensive time and effort to look at the options and, based on the results of their modeling, determined that these options would have very little overall impact on flooding along Otter Creek. In 2008, the results of the engineering studies were presented to the steering committee.

Since flood control was not a viable option, the Otter Creek Steering Committee looked at what could be done to limit the impacts of flooding along Otter Creek. They settled on removal of debris along with grading eroding streambanks to a 5:1 slope or flatter. This would allow them to be stable from erosion, opening the floodplain along the stream to slightly lessen flood impacts. By removing debris and regrading the banks, many of the old dikes and sediment berms that have accumulated over the years would be cleared away. Removing accumulated soil deposits allows flood waters to drain from the fields, enabling them to dry faster after a storm event. The steering committee and landowners signed in support of this activity as a start for improving the conditions along Otter Creek.

A grant was written by the Land Conservation Department (LCD) with support from the Otter Creek Steering Committee, as well as many other groups and local towns. A Targeted Runoff Management (TRM) grant was received from the Department of Natural Resources (DNR) and the Otter Creek project was approved to begin in 2009.

The TRM grant was originally meant to provide cost-sharing for 1.5 miles of streambank work to be completed in 2009 and 2010. Stabilization of the banks would include removal of soil to shape once-vertical streambanks to a slope of 5:1 or shallower, and planting grass. This allows floodwaters to overflow the streambanks without causing erosion and to more easily return to the stream when flood levels decrease. The removal of soil to accomplish slope reduction significantly increases the channel capacity. The engineering designs added some fish habitat structures to be installed at the same time the shaping work is done. While DNR shocking found minimal fish populations along this stretch, it was agreed that we should try to improve the stream for fish while the restoration work is occurring.

Ecological education was a priority goal of the watershed project. This was accomplished through direct personal contact and outreach efforts. We held several field days to view watershed conditions and conservation practices. Outreach included a website, documentation of project information, and distribution of information through mailings and presentations. John Exo, Natural Resources Educator from UW-Extension, created a website that posted overall project information as well as meeting minutes, presentations, and other resources. NRCS prepared an extensive report of their analysis, which we summarized in non-technical language and mailed to watershed stakeholders. NRCS then presented their conclusions at a stakeholders meeting. Local newspapers printed articles covering specific project topics and overall project progress.

The project surveying and contract work was completed in late 2009 and engineering work, along with permitting for the projects, was completed in 2010. Due to the time it took to get approvals for permits, a variance was granted to extend the grant through 2011. All construction will be need to be completed during this final year of the grant. Due to competitive bids from area contractors, we were able to sign contracts in 2010 for an additional .75 miles of streambank work for a project total of 2.25 miles of streambank restoration. In early January 2011, LCD staff began marking trees for removal this winter so the grading can begin in the  summer, as the weather allows.

The project includes 11,290 feet of stream-shaping along Otter Creek and over ½ mile of rock riprap to protect sharply angled eroding stream corners. The project also contains 165 habitat structures to be placed with the shaping and riprap. The habitat structures include 126 rock boulder placements, 18 log placements, and 21 rock weirs. The project also incorporates two stream crossings and a small wetland restoration. This will create nearly seven acres of native grasslands along Otter Creek, on the properties of seven landowners. Five of these sites are adjoining, creating one stretch of protected stream over 1.6 miles long. The work can be viewed at several bridge crossings along Otter Creek:  north of the bridge on Otter Creek Road, north of the bridge on Prairie Road, and north of the bridge on County Highway C.

Outside of the grant-funded work, some landowners will be seeding down additional areas to grass and signing additional acreage into the Conservation Reserve Enhancement Program (CREP),  which pays them to set aside cropland. This will help protect these fields from damage from the frequent flooding events along Otter Creek.