Big Round Lake

Water Quality

One measure of a lakes health is the trophic state, which relates to the amount of algae in the water. The average summer trophic state for the last 5 years was 71 (Hypereutrophic) and was determined using chlorophyll data. For a Shallow Lowland lake, this is considered Poor. Shallow Lowland lakes do not stratify, or form separate layers of water, during the summer months and have watersheds greater than 4 square miles in area.

Big Round Lake has been monitored by volunteers since 1992. Volunteers monitor water clarity with a black and white Secchi disk. Some also collect water samples, which are sent to the State Lab of Hygiene to be analyzed. Volunteers are the source of the majority of Wisconsin's lake water quality data, and their dedication is greatly appreciated. Additional monitoring has been done through projects funded in part by DNR Lake Grants and Aquatic Invasive Species Grants. Reports and graphs featuring data collected by volunteers, DNR staff and others can be viewed below.

Water Quality Reports and Graphs

Station Name	Station ID	Map	Max Year	Reports
Big Round Deep Hole South	10057676	Map	2023	Details
Big Round Lake - Deep Hole Near Milltown WI	493145	Map	2024	Details