Professional Lake Management (PLM) surveyed Clark Lake today (Tuesday, 6/7/16) to check the success of the weed treatment program that took place on May 18th.  Jeff Fischer commented “the offshore areas look particularly good.”  At the time of the comment, he had yet to examine all areas that had been treated.  As soon as results are complete, you will be able read about them on this website.  Jeff is a PLM representative and has a degree in marine biology and fisheries.  The photo below was taken today as he surveyed the lake.

Jeff Fischer

The pump system in the photo was not used in Clark Lake. Instead, granules were used. They fall straight to the bottom and attack the invasive weeds.

The treatment this spring is the first under the Special Assessment District (SAD) established by unanimous vote of the Columbia Township Trustees last August.

The quick spreading invasive weed is hybrid Eurasian water milfoil (HEWM) which can create huge problems.  Lakes that did not take action found that this invasive species greatly curtailed recreational use of their lakes, destroyed wildlife habitat and hurt property values.

The pre-treatment survey taken on Friday, May 13, showed about 30 acres of HEWM in the lake.  The growth areas were marked by GPS and those readings were used in targeting the HEWM–and only the invasive plant.

Clark Lake Treatment Areas May 2016 05-16

Jeff comments “this is a systemic treatment…the product causes the plant to grow wildly, extending spindly stalks, and then it collapses on itself.” The product used is Renovate OTF which is in granule form.  As the granules are administered, they fall directly to the plants.

Because a Special Assessment District (SAD) has been established, treatment of this weed will take place wherever it is found in the lake, typically in waters up to 20 feet deep.  For treatment to be effective, it must occur when the weeds are actively growing.

There may be a need for follow up spot treatments for stubborn patches or newly found growth, later in the season.  Those tentative dates are for the weeks of June 13, July 18, and August 18.

Notices were mailed to lake front property owners as well as posted on each property the day of treatment. According to PLM’s Steve Hanson, “Renovate OTF has been most effective in treating HEWM in lakes like Clark Lake.”  He also points out that the restrictions apply only to areas within 100 feet of treatment zones.  Much of the HEWM in Clark Lake is found along drop-offs or out in the middle of the lake, not within 100 feet of the shoreline.

Establishing the SAD was the culmination of a year-long drive by Clark Lake residents to stiffen the fight against this invasive weed.  When DNA testing confirmed its presence in the lake and a survey in fall 2014 revealed about 20 acres in the lake, these residents formed the Clark Lake Invasive Species committee. They quickly came face-to-face with an ugly truth of the threat HEWM poses. The SAD allows treatment wherever the weed is found in the lake. The SAD also supports the cost of the treatment through a $64.42 per year assessment to owners of each lakefront property.

Through private donations to the Clark Lake Spirit Foundation, four areas of the lake were treated early last summer. PLM performed the treatment with a permit from the DEQ and with the consent of property owners. Because of the limitation of property owner rights, the areas treated stopped at 250 feet from shore. HEWM grows in waters of up to 20 feet deep, and there is a lots of it beyond 250 feet. The SAD addresses this limitation.

The Clark Lake Invasive Species Committee consists of Clark Lake volunteers who researched the problem thoroughly and concluded the only way to deal with HEWM was by the application of approved herbicides. They then took the message door to door, held a public information hearing in December 2014, and last spring started a petition drive to create the SAD.  All along the way, progress was reported in detail on this website.  At the first public hearing in August 2015, committee chairman John Deming told the trustees and the audience about  community response.  “In taking the SAD concept to residents, the committee found overwhelming support–95% of lakefront property owners contacted by the committee signed the SAD petition.”  The committee delivered to the township petitions signed by 74% of the lakefront owners.  Columbia Township trustees passed the SAD resolution unanimously.