2022 State of the Lake Report

As has been the case for many years, FOFL completed the annual lake water quality testing on Finger Lake. In 2021, the testing program was not impacted by the COVID pandemic, and all testing was completed in the normal fashion. The Association is part of the Wisconsin Citizen Lake Monitoring Network (CLMN) and annually conducts four rounds of testing at the deepest point on the lake which is over thirty feet deep. All the supplies and lab testing services are provided by CLMN at no cost to the Association and CLMN works with the WDNR to assess the results we obtain to determine the state of the lake’s water quality and issues an annual report. Bill Abba and Sue Sazama conducted the testing in April, June, July, and August. If any lake resident wishes to participate in this testing program, please let Bill Abba know.

The results from the 2021 testing showed little change from the last few years. The brown color of the lake water, caused from the natural tannins washing into the lake from the surrounding watershed, remains though there did appear to be some reduction in the intensity of the color. Light penetration in the lake remains at around 12 feet which is consistent with last year. Summer oxygen levels dropped off to near zero below 15 feet like we have seen since the water level reached the very high levels we have experienced for the past 5 or so years. A thermocline formed at 15 feet in depth in the lake after ice out and remained until fall turnover when the whole lake mixes and oxygen returns to high levels at all depths. Oxygen levels were very good in the top 15 feet throughout the year. The results of all of the testing we conduct shows that Finger Lake is in very good shape with no concerning issues.

It is important to note that we do not test for bacteria in Finger Lake that could enter the lake from improperly operating septic systems. There is a point where it would be a good idea to test for leaking septic systems, possibly with a DNR grant. Leaky septic systems can contaminate lakes with coliform bacteria and excess nutrients which can cause health issues and algae blooms. There is no evidence of this happening right now, but we do not test for it at this point. All residents should keep septic tanks pumped as required by the State of Wisconsin and ensure their system is operating properly.

The one big change that occurred as the year progressed was declining water levels in the lake. By the end of summer, water levels had dropped several inches because of low rainfall. The decline reduced water levels to the point lake water was not draining into the outflow on Rangeline Road and, at one point, that pond nearly dried up. Reduced rain and snow fall can cause the water table to decline which can have an impact on lake levels. We will have to wait and see how much snow this winter brings to see how lake levels will be impacted going into next summer. I still believe that the significant reduction in the Southern Naiad nuisance plant we have seen the last few years is caused by the brown water color and high water levels we have experienced caused by heavy rain and snow falls and the resulting runoff of large amounts of tannins. Lower water levels may bring clearing, less brown water, and possibly heavier Southern Naiad growth. Time will tell.

Currently, water quality on Finger Lake remains in very good shape! Thanks to all residents for helping keep it that way. If you have questions or concerns, contact me.