Flowering Rush – Invasive species in Forest Lake
Informational /Open House Meeting
Meeting to be held on April 8 at Forest Lake City
Center
Forest Lake has recently become infested with an
aggressive aquatic invasive species (AIS) called Flowering Rush, sometimes
mistakenly called onion grass. Dense stands of flowering rush may interfere
with swimming and other recreational uses of the lake, and also choke out
native vegetation. Flowering rush is currently only in 2nd and 3rd
lakes and has not yet been detected in 1st lake. However, its spread
is imminent and it is only a matter of
time until 1st lake becomes infested. In 2014, the FLLA, in
conjunction with the CLFLWD and the City of Forest Lake, determined that an
effort needed to begin in order to rid Forest Lake of this invasive species.
The Forest Lake Lake Association (FLLA), in conjunction
with the Comfort Lake Forest Lake Watershed District (CLFLWD) and the City of
Forest Lake, is holding a public informational /open house meeting to educate
citizens and explain the planned treatment of Flowering Rush in Forest Lake
during the summer of 2015. The Informational /Open House will be held on Wednesday, April 8, 2015 from 6:30 to 8:00p.m. in the Forest Lake City Center (1408 Lake
Street South). This meeting is open to
all residents of Forest Lake and homeowners who live on Forest Lake.
Refreshments and light snacks will be provided.
Jerry Grundtner, a member of the FLLA Board of Directors,
said that “all entities are committed to begin the process of removing this
invasive species from Forest Lake before it reaches an uncontrollable presence,
and to prevent flowering rush from spreading into other water bodies in
Washington County and the State of Minnesota.”
The informational meeting will begin at 6:30 p.m. and from 6:40-7:45p.m., several guest speakers, including Blue Water
Science, representatives from the FLLA, CLFLWD and the City of Forest Lake,
will be present to share information on what flowering rush is, the planned
herbicide treatments and manual cutting that are scheduled to begin in July
2015, and will be able to answer any additional questions. The hope is that Flowering
Rush can be eradicated to allow Forest Lake to remain one of the premier lakes
in the region.
We hope to see many of you at the open house. RSVP is
preferred but not required.
History of Flowering Rush on Forest Lake
AIS are organisms that have been introduced, or moved by
human activities, to a location where they do not naturally occur. Due to a
lack of predators in new environments, AIS populations may grow exponentially
and choke out native vegetation. Flowering rush has been in Forest Lake for the
last 7-8 years and is steadily spreading.
Currently, Forest Lake does not have Zebra Mussels, Eurasian Milfoil, or
other aquatic invasive species found in Minnesota lakes.
It is not certain how it was transported to Forest Lake,
but flowering rush is extremely invasive and spreads in two ways: from the seeds
dropping from its purple flowers on top of the rushes and from the Rhizomes,
which are underground stems. The rhizomes are attached to the root system and
come loose when the plants are pulled.
Water currents, ice movement, muskrats and geese can easily move these
reproductive structures to new locations in the lake.
In July of 2014 Blue Water Science performed the initial
delineation of the Flowering Rush sites on 2nd lake and provided
markings and GPS locations of affected sites. On September 9, 2014, the CLFLWD contracted
with PLM, an aquatic herbicide treatment firm out of Detroit Lakes, to apply herbicide
to flowering rush identified on 2nd lake. On October 8, 2014 Blue Water Science went
back onto 2nd lake to assess the results of the herbicide
treatment.
From their assessment, it appeared that the application had
eliminated some of the targeted flowering rush but not all. It is important to remember that in all
discussions regarding flowering rush that it was always explained that this
would be a 2 -3 year process and that it would take multiple applications of
herbicide with the goal of eventually killing it completely.
Blue Water Science also performed a flowering rush
delineation on 3rd Lake on October 8, 2014. From the delineations in July and October it
has been determined that 2nd Lake currently has about 34 sites of
flowering rush ranging in size from 10 square feet (SF) to 1000 SF and 3rd
lake has 135 sites from 10 SF to over 50,000 SF (over 1 acre). This equates to
over 340,000 SF (approximately 8 Acres) of flowering rush identified. It appears that it is more invasive than
thought and is spreading more each year.
This is a multiyear effort and will require the
cooperation of all organizations and the homeowners who live on the lake. Maps
below show the extent and the locations of the flowering rush that were
identified in the delineations completed in 2014.
Sincerely,
Forest Lake Lake Association www.ourforestlake.com
Comfort Lake Forest Lake Watershed District www.clflwd.org
City of Forest Lake www.ci.forest-lake.mn.us
