Aquatic Weed Control

Picture a serene lake with sparkling water, inviting you to cast your reel for a trophy-sized fish, embark on a peaceful boating adventure, or take a refreshing dive. But an unwelcome intruder may be lurking just beneath the water, ready to entangle your lure, clog your motor, or snare your legs with a jungle of long tendrils. Lake weeds may not only interrupt your enjoyment of the water, but they can also be extremely hazardous to people, pets, and essential stormwater infrastructure.

Submersed lake weeds are just one aquatic plant category. Aquatic weeds can also be found floating on the surface or emerging from shallow waters around the perimeter of the waterbody. EPA-registered herbicides are effective tools to manage large infestations safely and rapidly, but they do not always get to the root of the problem. Aquatic weeds can reproduce in many ways that allow them to return after an herbicide application. These include seeds, spores, tubers, rhizomes (horizontal underground shoots), and fragmentation via small pieces of plant matter. Additionally, some stakeholders may prefer an all-natural management solution to their lake weed problem. To establish lasting control of aquatic weeds, and depending on the type of lake weeds you are dealing with, physical removal is sometimes the best or preferred option.

Aquatic experts can choose from a variety of removal methods based on the target lake weed species. Mechanical hydro-raking is a highly effective tool to physically remove the intricate root systems, tubers, rhizomes, and seeds that are buried in the bottom sediments. A hydro-rake is essentially a floating barge equipped with a backhoe that can dig out up to 500 pounds in each scoop. The sediment and plant matter are then deposited on-shore for disposal. In addition to removing entire plants, hydro-rakes help restore depth and volume to the waterbody to reduce the risk of flooding. 

Common submersed weeds:

• Watermilfoil
• Hydrilla 
• Mudmat 
• Fanwort

Hydro-raking, however, is not an effective method of removal for floating plants, which do not have true root systems. To target floating weed species through physical removal, aquatic experts rely on a floating mechanical harvester equipped with a cutting mechanism and a steel conveyor belt that transports plant matter to an onboard holding area. Once full, the plant matter is off-loaded at the shoreline for dewatering and removal. Because many floating plants reproduce through fragmentation, harvesting is recommended 2-3 times per season to maintain open water.

Common floating weeds:

• Water Hyacinth
• Water Lettuce
• Giant Salvinia
• Water Chestnut

In some cases, it may be difficult to remove emergent weeds with mechanical equipment without impacting the shoreline or delicate wetland areas. But in these cases, physical management is still possible through methods such as cutting and burning. Like some submersed weed species, many emergent plants have rhizomes and complex root systems that allow them to thrive for many seasons after a management program has been implemented. Aquatic experts may use strategic cutting, burning, and hand-pulling over the course of 2-3 years to eliminate them. Often, these methods must be used in conjunction with herbicide applications to be fully effective.  

Common emergent weeds:

• Phragmites
• Purple Loosestrife 
• Torpedograss
• Alligatorweed 

After becoming established, nuisance and invasive aquatic weeds can be extremely difficult and frustrating to manage. Once full control has been regained, it’s crucial to implement an ongoing preventative maintenance to ensure they do not return. Through an annual management program, aquatic experts incorporate comprehensive services that are tailored to the unique needs and characteristics of your waterbody.