The purpose of this site is to inform you of the harmful effects of Eurasian watermilfoil, the steps we are taking to control it and how you can get involved.  Our 2016 battle against milfoil is shaping up nicely and we have high expectations.  The new milfoil committee is working hard to ensure that we will be successful.

At the end of last season, even with the formidable labors of the milfoil crews, we found that we were unable to keep pace with the spread of the weed . Milfoil was growing where we’d never seen it before, and the existing patches were becoming harder to control. We decided that we needed to become more aggressive the following season and attack the milfoil with everything at hand. There are limited weapons that we are permitted to use on the lake and most require state permits. We currently have permits for machine harvesting, which is limited by the calendar, as well as bottom barriers.  We have initiated the permitting process for herbicides to be used in selected areas.  Hand picking, the old standby that needs no permits, is always available and is always encouraged.


The LDFLA has been very proactive in its efforts, creating a program to control the spread of milfoil.  Starting in 1989, the milfoil program consisted of volunteer “pullers”, who hand-cut and removed plants from Lake Dunmore and Fern Lake.  As milfoil expanded throughout the lake, so did the program, growing in 1994 to employ two divers to pull the plants from June through August, and again in 1999 to five divers.  These methods initially proved very effective, so much so, that in 2004, the association received the Environment Merit Award from the state of Vermont for their control of Eurasian Milfoil in an environmentally friendly way (i.e. non-chemical control).

The success of the milfoil program began to be severely tested in 2009 when the plant increased exponentially across the lake.  The cause of the proliferation has not been proven, but is believed to be linked to flooding that occurred in August of 2008 when a storm dropped five inches of rain in a four hour period in the region.  The flood caused many small cottage septic tanks to overflow into the lake and increased runoff, thus providing a nutrient-rich environment that aquatic plants like milfoil thrive on.  Over four times as many plants were pulled from 2008 to 2009; over nine times as many plants were removed from 2009 to 2011; and another substantial increase occurred in 2012.

In response to these increases,  the lakes association focused more money and effort on harvesting milfoil.  By 2010, the then six member dive crew was struggling to control the spread, so volunteer Allen Wilson helped obtain a permit for a different method of controlling milfoil—suction harvesting.  The following spring, Allen and the crew rigged a used pontoon boat to create a mechanical suction harvester, greatly speeding up the hand pulling process—divers no longer had to return to the surface with armfuls of harvested plants.  Instead, as divers pulled the plant,  they hold a long suction tube to literally vacuum up the plant, depositing it into a collection grate built into the pontoon boat.  Divers could stay down longer and pull many more plants.

LDFLA Milfoil Harvest Team

As divers had to clear larger infested areas, re-growth in previously maintained areas was inevitable.  Thus in 2012, the program expanded again by adding a second suction harvester and hiring full time crew manager.  Growth continued, and by 2015, the team had grown to four vacuum harvesting machines, a small service boat and a crew of 17 working 240 hours a week.

Current Status

The milfoil team is working hard to keep the invasive weed in check, but the cost of the program has dramatically risen over the past several years, and is only partially funded by resident dues and state and local taxes.  The addition of the boats, the suction harvesters and additional divers, has driven the yearly cost of the program from $25,000 in 2008 to $125,000 in 2012.  In order to ensure that Lake Dunmore and Fern Lake can continue to fund the milfoil program, the association launched the capital campaign Lakes Alive with a goal of raising $1,725,000, most of which to be placed in permanent endowment for the expressed purpose of protecting the water quality.

This campaign has been even more successful than expectations with over $2,000,000 pledged to date.  The milfoil has been even more widespread this summer, threatening to spread throughout the North Cove and expanding along the east shore across from the island.  The crews have cleared major patches, often working the boats two shifts each day.  Small patches and individual plants exist all over and at the end of the season they are being identified and removed.

The Future

Harvesting must be an ongoing process to just keep even with the milfoil growth.  More harvesters, crews and time on the water will be needed.  We have initiated the application process to use herbicides on the hardiest patches in the lake, and we hope for the permit to be issued by the 2016 season. Assuming we get the herbicide permit in 2016, we will be able to reduce the operation to three harvesters and less crew, but should be able to greatly increase production and hopefully keep the growth under control for the first time.

The committee is designing a GPS reporting system so homeowners will be able to easily report milfoil sightings and crew management will be faster and more precise.  In the meantime, you can use this link to report milfoil in your area using a zone-based system.

Read our 2015 State Grant-in-Aid Report

Read our 2016 State Grant-in-Aid Report

Read our 2017 State Grant-in-Aid Report

Read our 2018 State Grant-in-Aid Report

Our Main Tools

Below are the primary tools that we employ to fight milfoil on Lake Dunmore and Fern Lake.  Click below to learn more.

Suction Harvesting
Our main line of defense. Divers manually pull each plant from the bottom, carefully getting the entire root when possible. The entire plant is then sucked to the deck of the harvester boat where it is placed in buckets for disposal on land.

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We have been working closely with the state and also studying what other lakes have been doing successfully. The newer, more selective and specific herbicides do not kill most aquatic plants.  As such, we have applied to the state for a permit to use milfoil-specific herbicides on a very limited basis to address some particularly difficult patches.

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Other Methods

Addition methods we employ or have investigated to supplement our main tools.

Methods we employ

The LDFLA employs greeters at the public boat launch (near Waterhouses) to inspect boats and educate boaters about milfoil and other invasive species.  The primary way that invasive species are spread to and from our lakes are by clinging to the hulls of boats and trailers.

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This consists of posting an affected area with buoys to prevent boaters from creating fragments. We currently do this with the red and yellow buoys to limited effect. For us to actually cordon off an area is illegal and would require getting a state permit.

Methods we've investigated

These aquatic insects with an appetite for milfoil are so far an unproven technology.  We have a test section on Fern Lake we are watching. There have been some success stories on other lakes, but each lake is different.

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Bottom Barriers
We have applied for and received state permits to start employing Benthic (bottom) these next year. These are used where it is impractical to pull plants by hand, such as in rocky or clay soil where the diver’s fingers can’t get the entire root.