Resources and Guidelines

How-To Documents

Making Milfoil Mats


  • Unfold the mat completely.
  • Attach rebar at the two ends using 6” lengths of cord on every other grommet.
  • Add additional rebar about every three feet, which is every 2nd or 3rd grommet. It is better to have more rods than not enough. Our current 35’ mats typically have 19 grommets along the length, and placing rebar every other grommet gives 10 rebar/mat; a good number.
  • Weave the rebar through the mats by slicing a 2” lengthwise slit in the tarp using a box cutter, about every 2 feet. Keep the holes as small as possible; if they are too big the milfoil grows through the holes! The best technique for doing this is to lay the rebar in position on the mat, and then drag it off, which will leave a rust line on the mat. Then drag the rebar back onto the mat, cutting holes and weaving as you go. This makes it easier to pass the rebar back from the bottom to the top, and can be done by a single person.
  • Tie the ends of the rods to the grommets at the edges of the mat using 6” lengths of cord. (Note that the grommets occasionally do not line up, so if necessary, cut a hole near the edge of the mat to tie the rebar.)
  • Tie a foam float to the two corners of one end of the mat. (This makes the ends of the mat roll visible after being dropped on the lake bottom. We used to do both ends, but it got entangled in the protruding rebar ends.)
  • When finished, roll up the mat beginning on the end that does not have the floats.
  • Tie the tarp roll together with 3 lengths of cord. (There is no need to use slip knots; the divers will use their knives to cut the cords.)


  • Tarp: Premium, Green/silver Tarp, 20’ X 35’. Kotap America Ltd., Lawrence, New York. Tom Wynne has been supplying these tarps, at cost, for about $50 each.
  • Rebar: ½” x 20’ rods. Supplier has been TC Murphy Lumber, at cost, for about $8 per rod. This works out to $80 of rebar per mat
  • Avery cord: This is a ribbon-like synthetic cord. Also obtained through Tom Wynne, at cost. A possible labor-saving alternative is to use plastic slip-ties, but we have not tried that.
  • Small Styrofoam floats (Can be made from bright colored “noodles”, cut into 3-4” lengths.)

Note: Prices shown for materials are circa 2008.

Mat Laying Crews and Tasks

Mat Laying Crews and Tasks

Main diver will start / stop events. Once divers are down, pontoon boat captain will take over command.

Pontoon boat with “Captain”

  • Captain will start / stop event
  • Captain is in charge of diver’s safety
  • Will use megaphone, if needed, to direct operation or to tell other boats to stay at a distance
  • Will use underwater horn (or simply bang on boat) if divers need to come up immediately.
  • Megaphone and under-water sounding horn available from Karen Meltzer
  • Transport rolled mats.
Other motor boats

  • Assist captain with diver’s safety by keeping spectators in motor crafts away.
  • Shuttling divers or other volunteers when needed.
  • Drop and pick up “diver down” buoys
  • Carry spare mesh bags and surface nets
Canoes/ kayaks

  • 3-4 boats
  • Assist pontoon boat captain with diver’s safety by watching divers’ air bubbles, ideally one boat per diver.
  • While a few collection nets are available for use, please plan to bring your own (CrossRoads usually stocks inexpensive butterfly nets. The ideal implement is a pool skimmer.)
  • Collect any milfoil fragments.
  • Bring a plastic grocery bag to remove your fragment collection at the end of the day for disposal away from the lake. (Milfoil makes good garden compost.)
  • Keep other boats (spectators) away from diving area
  • Assist captain with diver’s safety by watching divers’ air bubbles

Additional Tasks for Hand Harvesting

Shuttle Boat

  • Collecting milfoil from canoes and kayaks
  • Bringing milfoil to shore.

  • Collect mesh bags from divers
  • Bring milfoil to shuttle boat
Milfoil Disposal

  • 1-2 people.
  • Equipment: 1 large garbage pail. A second small garbage pail may be useful.
  • Unload milfoil from shuttle boat as it is brought to shore.
  • When the work is over, dispose of the milfoil by taking it to the Town landfill, or compost it at a location away from the lake.
  • If the event is expected to produce a large amount of milfoil, i.e. one or more truck loads, arrange to borrow a truck from Brant Lake Camp and contact Doug Paton so that he can obtain a permit from the Town.

Shoreline Monitors Program

While this may seem obvious, the first step in controlling milfoil in the lake is to know where it is located. Historically, the location of milfoil beds came from lake residents and visiting fishermen who happened across the mifoil. More recently we have hired professional divers to not only hand harvest milfoil in known locations, but also to spend some of their time searching for new milfoil locations. However, it would be prohibitively expensive to have them do a complete survey of the lake. To address this problem the Brant Lake Shoreline Monitors Program was established in 2011. The lakeshore was divided into 14 approximately � mile sections, and trusted volunteers were solicited to be responsible for monitoring each section. This page provides functions to support this activity.

Contour Maps (2014)

AIM Milfoil Map (2012)