The Lower Nemahbin Lake Association (LNLA) has been busy working to ensure the health of Lower Nemahbin Lake.  Left uncontrolled, aquatic invasive species (AIS) could overtake the lake—reducing the ability to enjoy swimming, fishing, and boating activities as well as impact the value of lakefront properties.

Over the past year, the LNLA has engaged in the following activities, all with the goal of reducing the presence of aquatic invasive species in the lake:

Starry Stonewort Treatment:  Starry Stonewort (SSW), an aggressive invasive macroalgae, was discovered by an LNLA volunteer in the public boat launch access area between Lower and Upper Nemahbin lakes in late August 2019. Working in collaboration with the Wisconsin DNR, Waukesha County, and the Upper Nemahbin Lake Management District, the LNLA continued efforts begun in 2019 to remove SSW from the boat launch area. Key activities during the 2020 season included hand pulling in late July and August of 2020 conducted by Eco Waterway Services. A DNR survey of Lower Nemahbin Lake conducted at the request of the LNLA found no SSW in the rest of the lake. Funding for LNLA’s work in 2020 was made possible by a grant from the DNR and a contribution from the Upper Nemahbin Lake Management District. 

Nemahbin Starry Stonewort Time Line 2019-2020

Lower Nemahbin 2020 Treatment Summary submission

Eurasian Water Milfoil: Left uncontrolled this plant can take over a lake, until the only solution is very expensive weed cutting machines.

  • A survey conducted in the Fall of 2019 indicated 11 areas of EWM (see map below)
  • Spring 2020 treated areas #2 and #3 (about 2 acres).
  • Spring 2021 treatment is planned for same area as 2020

Clean Boats, Clean Waters (CBCW):  The CBCW program conducts trailer inspections and educates boaters on how to prevent the spread of AIS at boat landings. This summer represented the second year for LNLA sponsorship of this program. The program inspects and removes aquatic plants from boats and educates boaters with respect to draining live wells and other water containers. The program reached 780 boat owners this season, a 70% increase from 2019. 


[excerpt from LNLA Newsletter by Nancy Mathiowetz]

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Please make payment now by website or mail check for $40 to LNLA, PO Box 180151, Delafield, WI  53018