Benthic Barrier



The benthic Barrier is the perfect solution for suppressing troublesome aquatic plants that obstruct boating and swimmers. This lake bottom barrier is constructed of professional-grade nonwoven fabric and is typically framed and anchored to the bottom of a lake to block the sun and stop aquatic vegetation growth.

This fabric blanket can be placed directly over existing vegetation on the lake bed. As the plants beneath biodegrade gas bubbles will rise and push up on the fabric blanket making it is important to frame the benthic barrier with wood and have it weighted down and anchored so that it doesn’t move out of place and become an issue for swimmers or boat navigation.  

The barrier will need to be monitored 1 to 2 times a month to ensure large gas bubbles aren’t trapped or have moved the barrier. The frame may need to be lifted to let the gas “burp”. You can also make some cuts in the fabric to help release any trapped gasses. This maintenance becomes less of an issue once the existing plants have broken down.

A barrier like this can be built and installed by a property owner. The ideal time to install a benthic barrier is in the winter or when the plants have died back seasonally. This timing makes installation easier, however, should you need to install this in the summer or peak growth season then it’s advisable to first prune and cut back the existing vegetation.

Product Specifics

  • Series: Benthic Barrier
  • Size: Various
  • Square Feet / Roll: Various
  • Free Shipping
  • Need a Written Quote?
    Request Online > 
  • Volume Pricing Available on Large Rolls
         (widths 9 feet and above)
  • Questions? Call (800) 520-7731

6 oz Non-Woven Geotextile Fabric

  • Professional Grade
  • UV Resistant
  • Non-Biodegradable
  • Will Not Rot or Mildew
  • Resistant to Rodent and Insect Damage

All of our geotextile fabrics are professional-grade and are designed for use in both residential & commercial applications. Our fabrics are designed for years of continuous use in the designated application.


  • All Fabric Ships for Free (standard ground, see map)
  • Expedited shipping only available on orders over $2,000 
         Call: (800) 520-7731 for pricing and ship times

Shipping estimates shown on the map pertain to this specific product only. Fabric orders typically ship same day if the order is placed before 12:00 noon CST. Transit times displayed in the map are listed in business days, and are approximate. The day that the order is shipped is not counted as a transit day.



6" Landscape Staples



To the best of our knowledge, the information contained herein is accurate. However, Pro Fabric Supply cannot anticipate all conditions under which the above product information and the products which we distribute or the products of other distributors or manufacturers in combination with the products which we offer, may be used. We accept no responsibility for results obtained by the application of this information or the safety or suitability of the products we distribute either alone or in combination with other products. Final determination of the suitability of any information or material for the used contemplated, or its manner of use, and whether the suggested use infringes any patents is the sole responsibility of the user. Please note: Pro Fabric Supply is a distributor of geotextile fabric, not the manufacturer. We source material from a number of different United States based geotextile manufacturers.

How To Use Benthic Barriers To Maintain Control Over Aquatic Plants

If you don't know what Benthic Barriers are, they help control invasive aquatic plants. They have weighed tarps that operate similarly to black plastic mulch. These barriers are also known as bottom barriers or bottom mats. Benthic Barriers are very effective for controlling invasive aquatic plants such as Milfoil which are found in dense, small to medium-sized patches. Very active areas of invasive plants are found in boat channels, docks, and beaches that are controlled by using Benthic Barriers.

In areas where boating is prominent, it's advised the barriers are below 5 feet in the water. Control infested areas over 500 sq ft with Benthic Barriers are not recommended because of the price tag for installation and maintenance. You might consider using small mats that are around 5 x 5 inches placed strategically to locate and kill the invasive plants while allowing native plants to continue growing.

There is one big problem with Benthic Barriers, they are not selective. They will kill or damage all plants, both invasive and native, and will have a negative impact on fish and bottom-dwelling invertebrates. In general, plants that are not targeted are minimal but not totally eliminated. Eliminating Benthic Barriers when fish are spawning and cutting back in the area chosen to treat will help.

Not more than 10% of a selective area of water or the littoral zone of the water should be covered at one time. For areas that have high infestations, only cover a specific area then move the mats to the next area and repeat this process as needed every 60 days. The materials used for the construction of these barriers include fiberglass screening, geotextile, or another heavy-duty landscape fabric, along with an absorbent pond liner, and burlap.

Lakeside Cleanup

Cleaning Lakeside from Invasive Species

The challenges Involved with Installing a Benthic Barrier Includes:

One – The material is awkward and must be moved as quickly as possible to the chosen location on the water's floor.

Two - The material must be kept in place while currents and surface movements are taking place overhead. Also, releasing gasses from below will try and uproot the materials.

To start with, the mats have to remain in place which is a huge challenge and that must be resolved well in advance, then it's back to plans for transportation and placement. The material used for the Benthic Barriers will easily float and therefore must be tied down. As this is a big step, you need to know what you plan on doing ahead of time not upon arrival. You'll need to know what types of weights you need to use and how they will be placed well ahead of time. Some good anchoring choices include bricks, cinder blocks, rocks, and sandbags.

The weights will be lowered onto the mats in a pattern and its frequency is required to make sure the material remains flat on the bottom. If it's calculated correctly, the weights will be sufficient for holding down the mats. Another option is using rebar rods or rebars enclosed in perforated PVC pipe. The weighting devices are attached directly to the barrier material. In many cases, electronic ties are used to ensure they will stay in the right position on the mats. When using rods, some of them will be running across the width of the mat and can be attached before distribution and then rolled up in the mat to provide the required weight to get the mat to the bottom.

The rods that run along the sides of the mats will be installed later on when the mats are in place. It doesn't matter what material is being used for anchoring as the weight will vary depending on the depth of the water and other conditions including the water currents, the surface activities, the amount of plant material being covered, etc. The mats will be more stable in deeper, calmer waters. Some barrier materials are more porous allowing gases to escape under the barrier. There are other barrier materials such as geotextile and plastic tarps that are less absorbent having a habit of trapping gases. Keep in mind, the accumulation of gas can cause billowing and displacement. Before installing, you must have perforations at regular intervals beforehand. Two-inch-long slits can be created using a sharp knife or holes burned into the material using a wood-burning tool. Show caution when perforating the mats, only allow enough perforation to keep the mats from billowing without losing the mat's light-blocking integrity.

Even with the best intentions, boat anchors, swimmers, propellers, or other activities can dislodge or damage Benthic Barriers. Frequently conduct a visual inspection twice a month and perform maintenance to ensure the mats remain in place in order to be effective. Maintenance includes any possible repairs, the removal of silt, and releasing the build-up of gases so there are no billowing issues. You should mark the treatment areas and ask people to temporarily avoid any activities near the site. This will help keep down any disturbance issues.

Transporting and using the mats comes with advanced planning and good preparation. Underwater devices such as fiberglass rods or PVC pipes, floats, anchored buoys, and GPS to mark the perimeters and corners of treatment locations and the barriers once they are in place. You will also have to guide the control team to the sites for maintenance or moving to a new location.

For offshore sites, barriers must be constructed so they can be transported by boat from the shore to the designated location. Mats that have been constructed and packed for distribution are loaded onto boats and then transported to the treatment areas.

Creek with Invasive Plants

Invasive Plants in Creek

Team Members

One person will feed and guide the mats to the scuba divers who will take the mats to the lake floor. The mats are unpacked and spread out over the treatment area and then weighed down. If you have to perform manual harvesting along with barrier placement, the team might require more divers along with weed handlers, fragment spotters, etc. These barriers vary in size significantly while mats are chosen by various factors such as the size and configuration of the infested area for control. The number of people that will take on the task of installation and removal, the size of the boat to carry the mats to the assigned area, the kind of material and the amount of material, along with the required resources needed, the available storage space, etc. In general, the larger the mat, the more cumbersome it will be to move and maneuver. Most barriers are designed to be removed after the treatment period then cleaned, repaired, and stored for future use. In some circumstances, the barriers are moved from one location and sent to another location. In other cases, they are moved underwater. In some New England states, but not Maine, non-removable barriers made of non-synthetic natural fibers like burlap are installed and then left there becoming biodegradable.

Well-maintained reusable barriers can last for 10 years or longer depending on the material, how it's used, and maintenance.

Removable barriers that are installed during the growing season must be removed within 60 days of installation. The only exception to this rule are barriers that have been installed in the fall and the 60 days extends into the winter months. Mats left over the winter months must be removed at the start of the new growing season.

The cost for Benthic Barrier layering material will depend on the type, quality, and performance rating of the material. The New York State Department of Environmental Conservation estimates the added cost for installation is around $10,000 to $20,000 per acre. With the help of volunteers who are not only creative but energetic and dedicated, the lake groups in Maine are finding new creative ways to lower the cost associated with the installation of Benthic Barriers. Their impressive work is heading toward ways to have more effective methods for controlling invasive aquatic plants and without a doubt moving in the right direction toward the future.

Swamp with invasive plants

Invasive Plants in Water

More About Invasive Aquatic Plants

First off, invasive aquatic plants grow in marine and freshwater environments such as wetlands, estuaries, coastal areas, lakes, irrigation systems, rivers, aquaculture facilities, and hydroelectric systems. Invasive aquatic plants will cause a great deal of damage to the environment, our health, and the economy. These plants spread diseases, drive out wildlife and native plants, and can harm infrastructure.

These plants present a serious threat to all water environments including small streams to larger bodies of water. Invasive aquatic plants will reduce the quality of water, cost a great deal of money to control, and cause damage to the ecosystem. These plants create dense mats of vegetation that will block out sunlight and deny native plants the possibility of growth.