aquatic vegetation management – Aquarius-Systems

November 2025 Newsletter

Fri, 21 Nov 2025 15:10:12 +0000

Leaves Fall, Lakes Stay Busy!

A Message from Our Leader: Looking Back, Planning Ahead for Our Lakes

As the Leaves Fall, Harvesting Winds Down

When Communities and Harvesters Work Hand in Hand

What’s Really Happening Beneath the Water?

Apple River Flowage Wraps Up Another Strong Harvest Season

Thu, 23 Oct 2025 16:03:21 +0000

As the harvest season winds down, aquatic weed harvesters across the region are being pulled from the water and stored for winter. For many lake districts, this time of year brings a chance to reflect on the season’s results—and the numbers out of Polk County are impressive.

The Apple River Protection and Rehabilitation District (ARPRD) reported removing roughly 2.73 million pounds of aquatic vegetation from the Apple River Flowage as of June of this year. This follows back-to-back years where totals reached around 3.8 million pounds, highlighting a consistent and highly productive management program.

Keeping the Flowage Open and Healthy

The 640-acre Apple River Flowage sits within a watershed that covers more than 111,000 acres. As with many Wisconsin waterways, invasive and fast-growing native plants—like coontail and curly-leaf pondweed—can quickly limit boating access, trap nutrients, and reduce dissolved oxygen levels if left unmanaged.

Through consistent mechanical harvesting, the ARPRD helps maintain navigation channels, improve water flow, and reduce the buildup of decaying plant matter that can lead to poor water quality. Unlike chemical treatments, mechanical removal takes the vegetation out of the water entirely, helping reduce nutrient recycling and long-term regrowth.

A Sustainable Approach to Aquatic Management

Mechanical harvesting is one of the most effective and environmentally responsible tools for managing dense aquatic growth. By physically removing weeds rather than killing them in place, this method helps protect fish habitat, limit algae growth, and keep waterways open for recreation.

The Apple River Flowage’s ongoing success shows how local commitment, steady maintenance, and the right equipment can make a lasting impact on the health of a waterway.

Learn about ARPRD

February 2025 Newsletter

Fri, 01 Aug 2025 17:03:39 +0000

Water Warriors: Native Aquatic Plants vs Invasives

A Message from Our Leader: 2025 Lake Conference Season

Milwaukee: A Global Leader in Water Innovation

How Michigan Fights Road Salt’s Invasive Side Effects

Planting Native Aquatic Plants to Fight Invasive Species

Upcoming Conferences

Midwest Aquatic Plant Management Society 45th Annual Conference
Virginia Lakes & Watershed Association Annual Conference
Pennsylvania Lake Management Society 35th Annual Conference
National Water Quality Monitoring Council 14th Conference
Illinois Lakes Management Association Annual Conference
Western Aquatic Plant Management Society 43rd Annual Conference
Indiana Lakes Management Society Annual Conference
Wisconsin Lakes & Rivers Annual Conference

Florida Balances Hydrilla Control with Wildlife Habitat Needs

Tue, 05 Dec 2023 22:06:16 +0000

The Florida Fish and Wildlife Conservation Commission, the state’s lead agency for hydrilla control since July 1, 2008, faces a daunting challenge. It not only manages the spread of non-native hydrilla by spraying herbicides to maintain waterways for boating navigation and flood control. It also must consider the wants of Florida residents while keeping the best interests of wildlife foremost in its plans.

There is no disagreement that hydrilla has to be managed. But how it is managed creates passionate differences of opinion. Hydrilla can be excellent habitat for fish, waterfowl and marsh birds like the endangered Everglade snail kite. But unchecked, the non-native weed can rapidly overtake the entire surface of a lake, shade out native aquatic plants like eel grass and pickerelweed (also called flags), and lower dissolved oxygen content to hinder sport-fish growth.

Mechanical Methods for Aquatic Plant Control Explained

Fri, 17 Nov 2023 16:00:32 +0000

Mechanical control methods involve the complete or partial removal of plants by mechanical means, including: harvesting, shredding, mowing, rototilling, rotovating, and chaining. These management techniques for plants rarely result in localized eradication of the species, but rather, reduce target plant abundance to non-nuisance levels.

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

Aquatic Weed Growth in Wheeler Reservoir Creates Mixed Reactions

Tue, 20 Sep 2022 21:09:55 +0000

A recent increase in aquatic vegetation in Wheeler Reservoir in Alabama has anglers smiling, but local skiers, pleasure boaters and homeowners see the weeds as a menace.

Tennessee Valley Authority officials said they are hearing lots of complaints from homeowners and boaters about the hydrilla, eel grass, star grass and milfoil up and down the river. However, their focus is on maintaining access to the lake at ramps and developed recreation areas.

An aquatic weed harvester is used to to cut channels in the weeds on the water, to get in and out of these public access areas, but eradicating the aquatic plants can negatively affect the health of the waterway and impact the local economy.

Wild Rice Harvesting, Culture, and Restoration in Wisconsin

Tue, 07 Oct 2014 13:39:05 +0000

Wild rice is an annual aquatic grass that produces seed that is a delicious and nutritious source of food for wildlife and people. Harvested in the early autumn, wild rice was an immensely important commodity to Native Americans, particularly the Ojibwe and Menominee, who lived in the areas where it grew abundantly. The Menominee even took their name from the Indian word for wild rice, manomin, and were often referred to as the Wild Rice People by Europeans.

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

The History of Aquatic Weed Harvesters and Their Role in Waterway Management

Mon, 06 Feb 2012 11:58:17 +0000

Little thought is given to aquatic weeds unless you live or recreate on the worlds waterways. The aquatic plant harvester industry has grown in response to those concerns.

With Pictures of steam powered cutter boats dating back to the late 1890’s, we know that excessive plant growth has been a problem for a long time. At first, the problem was dealt with manually. People came up with clever tools to help make weed cutting easier. Others tried hand pulling the plants, but the going was slow.

The true origins of the harvesting industry began with a weed cutter boat built by the Hockney Company in Silver Lake, Wisconsin, in 1903. It is interesting to note that this machine was not originally built to meet recreational purposes; it was made in response to fussy Chicago housewives! Around the turn of the century, ice was harvested from Wisconsin lakes destined for Chicago iceboxes. The housewives there didn’t like cleaning out the weeds when the ice melted. Hockney designed this small boat, which featured a reciprocating cutter bar and duck-feet-like paddles for propulsion, to cut down the weeds in the fall so that clean ice could be harvested in the winter.

From this modest beginning many attempts were made to modify and improve these early cutter boats. In the early 1960’s, brothers John and Doug Dauffenbach founded D&D Products Incorporated located in North Prairie, Wisconsin and began manufacturing a more modern harvester which are still in production today, operating as Aquarius Systems. Like an underwater lawn mower, an aquatic weed harvester simultaneously cuts the vegetation, collecting and storing the weeds on board. The cutter head located on the front of the harvester uses sickles similar to those found on farm equipment, and generally cuts from one to six feet deep. A conveyor belt on the cutter head, which is always in motion, brings the clippings onboard the machine for storage. Once full, the harvester travels to shore to discharge the load of weeds.

Harvesters come in a variety of sizes, with cutting swaths ranging from four to twelve feet in width and up to five or six feet deep. The onboard storage capacity varies as well, and is measured in both volume and weight. Harvester storage capacities generally range from 100 to 1000 cubic feet of vegetation by volume, or from one to eight tons. They are usually propelled by two paddle wheels that provide excellent maneuverability and will not foul in dense plant growth. Harvesters may be propelled by twin hydraulically powered props.

Mechanical harvesters offer an environmentally sound method of controlling nuisance vegetation. As these weeds are removed from the lake, the water is immediately ready for use and there are no restrictions on use of the area that might be experienced with herbicide or some biological control treatments.

Removal of this biomass prevents its eventual decay and settling to the bottom, helping to reduce sedimentation in the lake. There is some nutrient removal with harvesting too, as the nitrogen and phosphorous that is bound up in the plant exits the water body. Harvesting is usually not lethal, leaving behind an oxygen and habitat producing plant, which is often desirable.

The aquatic weed harvester has come a long way from its crude and cumbersome origins. The future holds infinite possibilities. Some of the concepts being researched include: New paddle wheel designs for greater efficiency, a new hull design that more closely resembles the hull of a boat, and a remote controlled transport barge. We’re also researching ways to turn the harvested plant material into a marketable product. As the hydraulics industry evolves, this too will have an impact on changes in the harvesting industry.

We cannot be entirely sure how the harvester of the future will look, but with nuisance aquatic plant growth reaching epidemic levels globally, the industry is certain to be around for many years to come. We’ve learned over many, many years that nothing is impossible.

Mechanical Weed Harvesting Restores Malawi’s Shire River Hydropower

Fri, 18 Nov 2011 17:37:00 +0000

Ninety-eight percent of Malawi’s electricity supply comes from five hydro plants on the Shire River. An increase in floating aquatic weeds and debris caused serious operational problems at the stations and resulted in millions of dollars spent on repairs. For example, the intake structures at one plant were so blocked by accumulated weeds, water could not pass through. This situation created a vacuum in the intake tunnel while the machines were running; the result was a collapse of the intake screens. Repairing the screens and returning the station to service cost more than $12 million.

After several years and a couple of failed weed management programs officials needed a better way to minimize the effect of aquatic weeds to hydro plant generation and restore the beauty of the Shire River at the same time. That “better way” involved a mechanical means to combat the weeds including an Aquarius Systems weed shredder (Swamp Devil™), a mechanical weed harvester, a shore conveyor, and a trailer conveyor.

The Aquatic Vegetation Shredder was immediately put into operation. This boat contains two blades at the front, which are used for both propulsion and as cutters. It chops aquatic weeds into pieces about 15 millimeters long. In addition to collecting weeds that have been chopped by the automatic vegetation cutter, the weed harvester can cut and collect weeds that have not been chopped. Once the harvester is at capacity, it off-loads the weeds onto the shore conveyor and returns to work. In the mean time the shore conveyor transports the cut weeds to the unloading site on shore. Trucks then take the weeds to a designated depository site.

The success of the project can be measured on several levels. There have been virtually no plant shut downs after nearly three years running and the hydro station owners can operate its hydro facilities in an almost debris-free environment. This has allowed greater efficiency of the hydro stations and has improved the image of the company to its customers and stakeholders. The success is also measured by the social benefits in the nearby area. First, it has created jobs. The project employs a marine engineer and other marine technicians, in accordance with the national water machinery regulations. Second, depositing the weeds in farm fields is improving soil fertility. This allows local farmers to reduce their reliance on artificial fertilizers, which coincidentally is what provided the nutrients for the aquatic plants to grow and multiply to begin with.

Aquatic Plant Harvesters for Efficient Lake Weed Management

Mon, 12 Sep 2011 16:29:53 +0000

Aquatic Plant Harvesters offer an environmentally sound method of controlling excessive aquatic plant growth and nuisance vegetation in waterways of all sizes. These heavy duty work boats are highly efficient in the management of submerged, emergent and free floating aquatic vegetation.

Like an underwater lawn mower, an aquatic weed harvester cuts aquatic vegetation, collecting and storing the weeds on board. Aquatic weed harvesters are fitted with a pick up conveyor at the forward end of the machine, which can be lowered up to six feet deep to cut weeds. One horizontal and two vertical cutter bars sever the vegetation as the machine moves forward through the water, and, when the storage hold becomes full, the weed harvester returns to shore to unload.

Depending on the size of your lake, the type of your weeds, the percentage of weeds you would like to remove, and how quickly you would like to harvest them, we will work with you to design a fully customizable weed harvester to meet your exact needs.

Although many of our mechanical weed harvesters are customized to match the needs for your lake, a variety of models are available at stock sizes ranging between 100 feet³(or 1,500 lbs) and 1,050 feet³ (or 16,800 lbs) for capacity of cut vegetation held on board.