Mechanical Harvesting – A mechanical aquatic harvester (harvester) is a type of barge used for a variety of tasks, including aquatic plant management and trash removal in rivers, lakes, bays, and harbors. Harvesters are designed to collect and unload vegetation and debris using a conveyor system on a boom, adjustable to the appropriate cutting height, up to 6 feet below the surface of the water.

Shredding – Swamp Devils and Cookie cutters are small barges designed to shred aquatic weeds, equipped with engine-powered, front-mounted blades. The cookie cutter was developed to address emergent aquatic vegetation and floating islands of vegetation and sediment, and to cut openings in shoreline and wetland areas through emergent wetland plants (USACE).

Mechanical Control Methods – USACE

The Swamp Devil Aquatic Vegetation Cutter (formerly known as the Cookie Cutter) has been used on Lake Victoria since 1998 to help control dense mats of water hyacinth. A film crew from National Geographic visited our base in Kisumu for three days to shoot exciting footage of the equipment in action. While they were out on the lake, they happened to film a rescue made by the Aquarius staff, who retrieved two fishermen who had been trapped in their boat for two days, stuck in the dense weed growth.

The exotic water hyacinth has severely impacted the Lake Victoria region from both an environmental and an economic perspective.

Watch the Program

Botanically, wild rice differs from common rice, and is actually a cereal grass that grows in shallow lakes and streams, ripening in late summer. While the range of wild rice stretches from Manitoba to Florida, the most prolific stands are located in the upper Great Lakes of Michigan, Wisconsin, and Minnesota. Today Wisconsin has seventy major rice fields in thirteen counties. The grain usually begins to ripen in sections of the Wolf and Wisconsin rivers before lakeside areas are ready to be harvested.

Only Wisconsin residents may harvest wild rice in the state and must purchase and possess a wild rice harvesting license.   Harvesters are limited to gathering wild rice in boats no longer than seventeen feet and no wider than 38 inches that must be propelled by muscular power using paddles or push poles. The grain is still harvested by hand using wooden sticks (flails) that bend the tall stalks over the canoe. As the seed heads are tapped, some rice falls in the canoe and some in the water to seed the bed for future years. The flails must be rounded wooden rods or sticks no more than 38 inches long and hand-operated. Harvesting should be done gently, so that the stalks and beds can be harvested again as more rice matures.

Many of the large wild rice beds in Wisconsin have been lost due to pollution, exotic species, large boat wakes and especially changes in water levels.  Dams erected many miles away can also affect the harvest, for wild rice grows in the shallow parts of lakes and streams, maturing best if a fairly constant water level is maintained. The primary method of wild rice lake management is by controlling water levels on the lakes by operating water control structures (dams), ditch maintenance, and beaver dam management.  Aquarius Systems’ equipment is also used to help maintain the wild rice by removing aquatic vegetation and helping to restore the flow of water.

An aquatic vegetation cutter (AVC) better known as a Swamp Devil® effortlessly plow through bogs, water hyacinth, cattails, small trees, tulle, tussocks and other stubborn growth.  In the process it also carves through the subsoil creating an open water channel up to three feet deep and eight feet wide, allowing the water to once again flow freely.

Learn More about Wisconsin Wild Rice