2023 Annual Meeting Presentations

The meeting began with a power point presentation on the state of the lake. Conservation efforts gong back to the 60’s and 70’s were discussed up to present date.

A significant portion of the presentation centered around the major issue of why Beaver Dam Lake is an impaired body of water, that is nutrients and specifically phosphorous. Phosphorous is the limiting nutrient for the growth of algae. It is the reason the lake has such a serious algae problem for most of the summer, to the point of health warnings to avoid contact with the water at times. The phosphorous in the water column that is available to algae comes from a number of sources. A chart was presented from a 2018 engineering study showing that 30% enters the lake from the watershed, runoff from agricultural practices, from residential properties, and other surfaces.

45% is due to the lakes overpopulation of rough fish. This is because we have decades worth of silt and sediment at the bottom of the lake that contains phosphorous. The rough fish stir up that sediment through their feeding habits and release some of that phosphorous into the water column, and additionally their excrement releases phosphorous. The fish themselves can not create phosphorous, they simply facilitate moving it into the water column. The rough fish, like all living things, contain about 1% of their dry weight ( roughly 90% of their body is water) as phosphorous, so when a million pounds of rough fish are harvested, about 1,000 pounds of phosphorous is physically removed from the lake.

20% is due to stratification where low dissolved oxygen levels at the bottom of the water column result in phosphorous being released from the sediment. The balance is from shoreline erosion and minor sources.

2023 Presentation PowerPoints