Lake water quality improved again this past summer. Our blue green algae microcystin levels in 2017 were lower than any we have recorded. Because our weekly water tests gave little concern for blue green algae blooms, no copper sulfate treatments were completed.
We believe lower phosphorus concentration in the lake is responsible for the decline in blue green algae. During 2016-2017, phosphorus averaged 22 parts per billion (ppb) compared to an average of 187 ppb during 2013-2014.
During the past four years, we implemented an aggressive program to combat our microcystin worries. We dredged phosphorus enriched sediment. We treated the lake with copper sulfate when our weekly lake water monitoring tests caused concern. Also, we eliminated geese and installed aerators on a trial basis.
Individual home owners did their part too. They used phosphorus free lawn fertilizer, harassed geese so that they seek other environments, refrained from feeding geese, and kept clippings out of the lake and drainage ditches to prevent additional nutrients making their way into our water. They adhered to boating rules, both the no wake/idle speed only rule and ‘no plow’ rule, to minimize stirring of bottom sediments rich in phosphorus. On the lake front, they made sure the shoreline was adequately protected to prevent erosion. Also, erosion was controlled on construction projects involving bare earth.
Also, we think there was less phosphorus moving into the lake from the watershed. Improved farming techniques, decreased phosphorus use, riparian areas, cover crops, and cooperation of watershed farmers made an impact.
For a printable and downloadable Lake Water Quality Summer Review