Lac Notre-Dame and Usher Lake Association

Eurasian Milfoil

Originating in Europe, Eurasian watermilfoil is an invasive aquatic plant that usually grows at depths of 1 to 4 metres and can form a dense carpet on the lake’s surface. According to Environment Canada, “this plant not only pushes out indigenous plant species, but may also be harmful to fish populations by crowding out their spawning grounds.”

Take steps to reduce weed levels

  1. Each broken-off bit of weed can turn into a new plant. Avoid areas of the lake infested with the plant, particularly with motorized boats. The worst mats are marked by Association buoys in bad summers - stay out of those areas with any kind of boat at all.

    • Milfoil bits may also drift in that have been cut up by boat motors, and lake residents are encouraged to remove them from the lake - use them as compost far from shore.
  2. Cutting does seem to help, as long as you remove the cuttings. Lake residents who have been consistently cutting the weeds for a few years notice that fewer and fewer appear. Try not to stir up the bottom as you cut - that just moves food into the water for the weeds. Raking is not advised at all.

  3. Stop sediment from entering the lake - it feeds the weeds. Maintain the natural vegetation along the shoreline or restore degraded shorelines to reduce sediment inflow. Rehabilitate your shoreline with native plants like Red Osier Dogwood, Pussy Willow, Sweet Gale and Blue Flag iris, as outlined in the Ottawa River Keeper Guide below.

  4. Stop nitrates from fertizers and phosphates from detergents from entering the lake. These nutrients feed the weeds as well as damaging the overall health of the lake.

History of Milfoil in Lac Notre-Dame and Usher

The Association was founded in 2004 in response to the Eurasian Milfoil explosion in the lakes. The Association received valued advice and assistance from biologist Paul Hamilton of the Canadian Museum of Nature. Mr. Hamilton has continued to support the Lake’s efforts by monitoring our water testing results and advising us about important changes in the water quality.

  • Electric cutter history: An electric cutter was purchased before 2008 by the Association, with a financial contribution of $6,400 from the Municipality of La Peche and is stored at Bob Scott’s.

The cutter required mounting on a barge and a team of 10-12 volunteers to manage both the cutter and the manual labour
of removing the heavy cuttings from the water. After a few years, as the weed levels naturally declined, & the cutter
was no longer used due to the huge amount of effort required to organize a volunteer team, boats, fuel and strong
bodies. The barge was destroyed in 2010, as it was stored at Camp Kalalla, and was a danger to the camp.

  • The Association did not renew the insurance for the cutter; therefore future users would need to sign a waiver to borrow the cutter and would have to return it in the same condition that they received it in. No one has done so since 2010.