Erosion Study Project

University of Wisconsin, Steven's Point

New Study to Help Lakes and Farms Solve Erosion Issues
Start-Up Discussions First Step in Working Together

COLA recently commissioned the University of Wisconsin - Stevens Point to conduct an erosion study of the Upper Couderay River Watershed (UCRW). COLA initiated the study as part of COLA’s WDNR-approved LCO Lake Management Plan.

The erosion study, now completed, contains the modeling and mapping necessary to help both farmers and lake associations in the watershed identify farm parcels most vulnerable to erosion. The goal now is to encourage farmers, with the help of county conservationists and others, to adopt appropriate management plans. Because all lakes in the watershed ultimately flow into Lac Courte Oreilles, the erosion study was designed to provide guidance on protecting productive soils in the watershed as a means of ultimately preserving the water quality of LCO.

The Upper Couderay River Watershed (need link for map) covers 125 square miles and contains 12 billion gallons of water. Those lakes most affected by agricultural erosion include Round Lake, Lac Courte Oreilles, and Sand lake. In total, there are 10 lakes and 10 lake associations (true?) in the UCRW.

Erosion is a concern for farmers because exposed topsoil can be washed away by rain and snowmelt, or blown away by wind. This reduces the overall productivity of the land and contributes to the sediment load for streams, rivers and lakes.

Water bodies near agricultural operations face serious additional threats from erosion. In the UCRW there is a mixture of animal and crop production, mostly dairy, beef, corn soybeans, and various forages such as alfalfa. Manure from dairy and beef operations is commonly spread across farm fields as a means of recycling animal waste. But manure is very high in phosphorus, and if manure is not handled in a timely and appropriate manner, it will be carried by runoff into nearby waterbodies, along with misapplied fertilizers and pesticides. Manure applied in winter can be is particularly damaging. The ground is frozen, and when the spring thaw starts, manure runoff will seriously degrade water quality in streams, rivers, and lakes.

To address these problems, two scientists from UW Stevens Point, Douglas Miskowiak and Kyle McNair, used techniques developed by the WDNR to identify erosion-prone areas in the UCRW. They used large, map-based databases to combine information on elevation, precipitation, crop rotation, crop management, drainage, soil erodibility, and runoff potential into an Environmental Vulnerability Index. This index can be viewed on a parcel by parcel basis and used as a first indicator of erosion potential.

Those parcels with a high Environmental Vulnerability Index value will undergo on-site verification, and COLA is encouraging Sawyer County and the Natural Resources Conservation Service to assist COLA with this task. Producers on erosion-prone land should implement best-management practices to address potential or existing problems. This overall plan of activities is in accordance with the commitments laid out in the Sawyer County Land and Water Resources Management Plan that has been approved by the WI’s Department of Agriculture Trade and Consumer Protection.

COLA can’t take on responsibility for the entire UCRW alone, and the intent has always been to share this watershed-wide work with other lake associations, county conservationists, and agricultural producers. COLA will help all parties in the watershed do their part to protect area lakes.