That green stuff you see everywhere isn’t algae – it’s duckweed, one of the smallest flowering plants in the world!
What is duckweed?
Duckweed is a very small vascular plant that thrives in shallow water. It loves the lake’s shallows, because it can take advantage of all the nutrients that the shallow lake sediment gives off.
Why don’t you get rid of it?
Duckweed can double its number in just a few days. So even if we skimmed it off the top of the lake, it would come right back. We also can’t spray herbicide on it, since Sharon Woods Golf Course is irrigated with lake water and the herbicides would kill the turf on the golf course.
Why has it gotten so much worse?
Think of the reservoir basin as a bowl that accumulates sediment and nutrients from the surrounding watershed over the years. Sharon Lake was dredged in the 1980s, but streambank erosion in the watershed has continued to bring sediment in and fill in the lake over the past 30 years. This sediment has accumulated at an unanticipated rate, creating shallow areas where duckweed can thrive. Now that there are acres of shallow water, there’s a continuous source of nitrogen and phosphorous from the soils that also fuel that duckweed growth.
What’s the solution?
Dredging the lake is the only long-term solution. Great Parks is beginning the environmental studies for this expensive and complicated project in the coming months.
Who can I talk to if I have more questions?
Please contact our Natural Resources Director, Bret Henninger, via email
or by phone at 513-521-7275.