Big Chetac Lake is a 2400 acre, shallow, highly eutrophic or nutrient-rich lake that forms the headwaters for the Red Cedar River near Birchwood, WI in southwestern Sawyer County. It is the top lake in a three lake chain which includes Birch and Little Birch Lakes. Water from the system exits Little Birch Lake over a small dam and then joins the Balsam-Red Cedar-Hemlock Chain of Lakes. In 2007, The Big Chetac Chain of Lakes contracted with SEH, a natural resources consulting agency to complete a six-phase multi-year lake study. The study was designed to determine the causes of nutrient enrichment in the system.
Big Chetac and Birch Lakes Association
Phase One collected water quality, lake level, and tributary information. Phase Two collected groundwater data, looked at the internal loading of nutrients into the lake, and evaluated the nutrient contributions of an aquatic invasive plant species, curly-leaf pondweed. Phase Three completed full nutrient and water budgets for the lake. Like a bank account, a budget determines what and how much is coming into the lake and what and how much is going out of the lake. Phase Four completed a historical analysis of the water conditions in the lake by collecting sediment cores form the bottom of the lake. These cores went deep enough in to the sediment at the bottom of the lake to determine water and lake conditions back over at least a century. Phase 5 evaluated the aquatic plant abundance, density, and diversity in the lake. Phase 6 included a Lake User Survey distributed to as many local lake residents as possible. Survey results are being combined with all data collected in the other phases to draft a Comprehensive Lake Management Plan and Aquatic Plant Management Plan for the Big Chetac Chain of Lakes. These plans will make recommendations and outline activities that could reduce nutrient loading that is turning the lake excessively green, improving the overall health of the entire system.
It is expected these activities will be implemented through funding obtained from a variety of sources including lake residents, local town and county authorities, and through several State of Wisconsin cost-share grant programs. Volunteer time and donated services and materials will be used to help offset the financial burden to the Big Chetac Chain Lake Association. Plant management, specifically for curly-leaf pondweed control, and activities to reduce runoff over the near shore area, improve the watershed, and to promote greater Lake User understanding of the processes at work in the Big Chetac Chain of Lakes are scheduled to begin in 2010.
Phase 7 started once the Lake Management Plan Report prepared by SEH was presented to the Lake Association and Approved by the DNR. The DNR provided the Lake Association with their recommendation on what they would like to see in the final Lake Management Plan that they chose to adopt. The Lake Association then formed a committee to create an actionable Lake Management Plan with input from the DNR. That management plan was drafted in 2010 and put into final form and later adopted by the Lake Association.