Once again, we started the Spring with what appeared to be Aquatic “Plant Free” lake. The shore clean-up was light at the start, but we know we have a very fertile lake that is perfect for growing aquatic vegetation and we knew it was just a matter of time before the plants will get heavy if we don’t start cutting aggressively.
The District does water quality testing every Wednesday morning. As part of that testing, we check water clarity (with a Secchi disc), Temperature, Oxygen levels, and Salinity. The Secchi disc is what is used to measure water turbidity or clarity. The clarity of Pewaukee lake has been improving greatly over the past 20 years and the Eurasian water milfoil has continued to decrease significantly. To date the lake has one of the highest diversities of plant life in the state. While most people hate “weeds” or aquatic plants, they are what makes a lake healthy. Plants intake nutrients and release oxygen into the water. Fish, frogs, turtles and other aquatic life need oxygen to grow healthy and strong. Without the aquatic plants intaking the nutrients, we would have algae showing up to consume the nutrients which then creates an algae bloom and it turns the lake to pea green soup.
Over the last 10 years we have seen an increase of the filamentous algae which has the appearance of clouds of green “cotton candy”. These algae are considered a “good algae” although it is uncomfortable for swimming, makes it difficult to fish and is not very pleasant looking. Some algae are good for a lake. It provides food for the zooplankton and all the microorganisms. Minnows and year of the young fish, feed on the zooplankton and the bigger fish feed on the smaller fish. In essence, the algae are the start of the whole food chain and is good for a lake as long as it is not a huge algae bloom or the nasty Blue Green Algea. The Blue Green Algae has shown up a few times and it usually does down by the beach where the seagulls are deficating and in areas where the water stays stagnant. We need just enough algae to keep the lake healthy yet we don’t want it to proliferate or turn into the bad blue green algae. So, to help minimize the algae, we recommend that lake residents and neighboring properties that drain to the lake to not fertilize their lawns with nutrient rich fertilizers as this can make the algae blooms increase exponentially.
The aquatic vegetation is just now starting to flourish, and our crews are on top of it. They are giving the invasive aquatic plants a good “haircut”, so we are keeping the vegetation at bay but maintaining plants to at a 12”- 18” height to help hold the lake bottom from eroding from high winds and large wave action. Keeping the plants well below the surface helps minimize the prop chop that creates all the floaters. While we are putting the crews in full force, we cannot emphasize enough how much more efficient we can remove the weeds if the lake property owners participate in the pile pick-ups on Mondays and Fridays. The Lake Pewaukee Sanitary District started this process many years ago and to date, other Lake Districts have been following our lead. This “pile pick up” is on Mondays and Fridays weather permitting. We send crews out to pick up piles of weeds that the lake homeowner’s have stacked up on the shoreline. While this does take effort from you, this effort goes farther than you think. If your Aquatic plants are piled, we can move around the lake quicker, pick up more weeds faster and it allows us to clean more shoreline and harvest more aquatic plants.
If you cannot possibly do this, there are high school and college kids willing to do it for you and it is not that expensive. It is no different than hiring a lawn service because you want a better lawn. Call our office for more information, as we like to work with these services and are even willing to pick up the piles they make. Our position is the more invasive aquatic plants we can remove from the lake the better off we all are.