Figure-1 One of the original test installations by ABV des 7
The Do-It-Yourself (DIY) dock kits are the result of the 3-year test done by an environmental group called ABV des 7, in Québec, Canada. The test was completed in 2015 and took many people, but yielded exceptional results. Establishing the barrier involved laying a biodegradable burlap fabric on top of the Milfoil, with sand bags to hold it down. It demonstrated that it will kill off the Eurasian Milfoil in its first season with the burlap, then biodegrading over a 1 to 3-year period.
Figure-2 shows the edge of one of those original test installations, 4 ½ years later. The image shows how dense the Milfoil was before the installation and how well the burlap worked.
The manual installation process was later refined so that a DIY kit could be installed from a single boat with only 2 to 4 people in it. It can be easily installed down to 8 feet (2.4m) deep, but installing it down to 12 feet (3.6m) is also possible with a little more effort. The deeper depths require the boat to be further ahead of the roll to keep the installation ropes at a shallow angle. It provides a simple way to kill off Milfoil in swimming areas and adjacent to private docks.
Figure-2 The edge of the original test installations, 4 ½ years later
More detailed installation instructions will be provided with the kit, along with to access to an installation video to be made this summer.
The DIY Burlap dock kit
The DIY kit includes a burlap fabric sheet which covers a 12.5 ft wide X 33ft long (3.8m X 10m) area along with 18 empty burlap sand bags and instructions. One end of the burlap sheet is folded over and sewn to create a sleeve.
The burlap is installed by unrolling the fabric on top of the Milfoil infestation and holding it down with the supplied bags (filled with about 5 pounds of sand) or similar weight rocks from the shoreline. The Eurasian Milfoil is killed off by the burlap holding the fragile plants to the lake bottom.
The customer is required to buy a 1” dia. X 10ft long metal electrical conduit (metal tube or pipe), 100 feet of ¼” dia. rope and a roll of electrical or duct tape. All of which can be re-used for multiple kit installations.
- Any other 10 ft or 12 ft pipe can also be used, e.g. 1-1/2” dia. conduit, ¾”-nominal pipe, 1-½” ABS pipe, etc. All are suitable. A 1-1/4” dia. X 10ft long metal fence tube was used in the Figure-3 photo.
- If wood is used (e.g. 2”X2” spruce), more weight needs to be added to the burlap sleeve end to offset the floatation of the wood.
To install the kits, the following process is used:
- Open the kit and unfold the burlap in an open area
- Add approximately 15 pounds of local sand or small stones to the end sleeve
- evenly spread it throughout the sleeve leaving 1-foot empty at each end
- Cut the 100-foot rope in half and tie the two 50 ft pieces to the pipe. Use the tape to hold the 2 ropes evenly spaced at 8 feet apart (1 foot from on each end of a 10-foot pipe or 2 feet from each end of a 12 ft pipe)
- Lay the pipe, with ropes at 90° on top of the burlap as shown in Figure-3
- note that the pipe does not need to extend all the way to the ends of the burlap
Figure-3 Installation rope/pipe on burlap. Rope tied and taped on pipe
Roll the burlap up like a carpet roll, with the pipe and rope inside. This is done in such a way that the ropes are continually rolled up with the burlap. See figure-4
Figure-4 Burlap, pipe and rope, partially rolled up
- Completely roll the burlap up and wrap the remaining rope around the roll so that it can easily be transported to the installation location. See figure-5
Figure-5 Kit in transport configuration
- Fill each of the 18 sand bags with approximately 5 pounds of local sand (a shovel full) or collect 18 rocks of similar weight to hold the burlap down during installation. Local sand is recommended, since similar sand is already in the lake. So it will not change any lake chemistry.
- To start the installation, the roll is placed in the water and the first 2 feet of the roll is unraveled. See figure-6. At this point the first three sand bags or stones are placed on the end of the burlap to hold it down. One in the middle and one on each end.
Figure-6 Kit in installation configuration
- The burlap is about 40% heavier than water when wet, so once it soaks up water (in a few minutes) it will stay on the bottom. Submerge the entire roll in the water. After the full roll has been saturated, installation can begin.
- The roll will now easily unravel underwater as the 2 ropes are pulled up and forward. Pulling on the ropes forces the burlap roll to unravel, since the 2 ropes have been rolled up with the burlap.
- Once the roll moves into greater than 3 or 4 feet of water, the remainder of the installation can be done from a boat. See figure-7. It is best to keep the boat ahead of the roll, so that the ropes are approximately at a 45° angle. Should the roll come up against an underwater obstacle, the ropes can be pulled on at a steeper angle to help lift the burlap roll over the obstacle to continue unraveling.
Figure-7 Kit in installation configuration
- The 5-pound sand bags or rocks can be dropped 3 at a time for every 6 feet of burlap that is unraveled. Drop one in the middle and one close to each side.
- When the roll is completely unraveled, the previously installed sand or stones in the end sleeve will hold the end down. At this point the installation pipe can be pulled up with the ropes attached to it and used for other installations.
Once the burlap has been installed, the area is free from Milfoil. Be careful not to get fishing hooks caught in the burlap, since they could pull it off the bottom or out of place. Heavy power boat acceleration in shallow areas could also move the burlap out of its position in the first season or 2.
The burlap process kills the Milfoil off by holding the frail Milfoil plant to the lake bottom. As such, it is less effective if the lake bottom has large rocks close together, since the fabric will drape across the rocks. It will cover a sunken log, but is not suitable for covering submerged trees with branches.
The burlap process is not suitable for other water vegetation. It works on Milfoil, since it is a frail plant that can be held to the lake bottom. If there were any other indigenous plants in the area before the Milfoil dominated the area, those plants will most likely grow through the burlap and regain their dominance once again. This effectively helps to restore the original lake ecosystem.
 ABV des 7, is a non-profit environmental group responsible for the 7 watersheds North of Gatineau, Quebec, Canada. They consider Eurasian Milfoil as their number one environmental challenge. www.abv7.org