FAQs

What is an aquatic noxious weed and how do I identify them?

A: Every state has its own noxious weed list and this list will tell you whether the plant is growing on land or in the water. Noxious weeds are plants which have been identified as aggressive, meaning they can disturb or damage native wildlife habitats, crop and domestic animal production and/or human activity.

How do I know the difference between a good water plant and a noxious water weed?

A: Your state’s Department of Ecology has likely developed a book that contains photos, drawings and information about water plants. There are a variety of differences in plant species that act as identifiers, from life size and shape to habitat and tolerances.

What water plants are you trying to control or kill?

A: One of the most invasive plants we have in Northwest waterways is the noxious weed, Eurasian watermilfoil (EWM), a plant that can clog a lake or river and cause damage to the native plants. Because EWM can grow faster than the native, water plants, it reaches the surface and blocks the sun from the native vegetation. If the native plants don’t grow, many water birds that use these plants for nesting will only have EWM, which can be a problem by tangling up baby birds.

Also, thick mats of EWM can slow water flows, warming the water (which can squeeze oxygen out of the water) and make the water environment conditions hard on fish. Fish can spawn in EWM, but once it gets real thick, the fish don’t have quality habitat.

Flowering Rush is another invasive/noxious weed that has become an issue in our waterways. It’s aggressive growth has a lot of negative potential for the Northwest’s aquatic ecosystems, so Lakeland has been at the forefront of detecting and eliminating the plant as much as possible, before it spreads even further.

Some other aquatic noxious weeds in the waters of the Northwest are curly leaf pondweed and hydrilla. Shore line noxious weeds include phragmites (an invasive grass), yellow flag iris and purple loosestrife (escaped ornamentals), and tamarisk (also known as salt cedar). Keeping a wide variety of native plants in the water and along the shore can make conditions better for wildlife.

Can I remove Eurasian Watermilfoil (EWM) on my own by using a rake or pulling it by hand?

A: We prefer you don’t remove EWM unless you can get the whole plant. EWM can grow from small pieces of its stem, so when it breaks up, from raking, pulling or chopping with boat props, the problem can get worse.

If you think you have EWM in your waters, contact your local Noxious Weed Board or office and let them know; they can conduct a survey and positively identify the plant and determine the treatment for control.

If pieces of EWM wash up on your shore, remove them upland so they don’t return to the water. You can get rid of EWM by putting it in the garbage or composting it in your landscape.

FAQs

I have all kinds of weedy plants around my dock that make it hard to swim or use my boat; can I remove those plants?

A: It’s not a good idea to remove native aquatic plants because established native populations can limit the spread of EWM into the area. Plus you have good fish habitat.

Some states, like Washington, require a permit to remove native plants along your shore line. Limited dock and beach access clearing by hand or rake can be done under a Washington Dept. of Fish & Wildlife (WDFW) “Aquatic Plants and Fish” pamphlet; contact them for more information.

What kind of pesticide are you using in the water?

A: The product we use in the water to control or kill water plants is an herbicide, the same products you use in your landscapes or pastures to control weeds.

The herbicide active ingredients used most often are Diquat, Hydrothol, and Aquathol. You can find great information about these herbicides at the National Pesticide Information Center (NPIC) website. They have information sheets about these and other herbicides.

 How are you spraying the herbicide on the plants?

A: The herbicide is applied either as a liquid product or a granular (pellet) product; it depends on the weed being controlled.

The liquid herbicide is applied from an airboat (much like those used in the Florida Everglades). A system of hoses is put into the water from the front of the boat, which are attached to a tank inside the boat. The tank is filled with the herbicide and water from the lake and/or river is sucked into the tank, mixes with the herbicide, and then is injected underwater to where the noxious weeds are located. Shoreline plants or emerged plants are sprayed with a hose and sprayer attached to the airboat, a backpack, or an ATV.

The granular herbicide is applied from a rotary spreader mounted to the front of the airboat. The spreader is a larger version of what is used on land (like a Scots® fertilizer spreader). With a large, open container that is filled from the top, the spreader distributes the granular herbicide across the surface of the water in a wide sweep. The pellets sink to the bottom where the aquatic noxious weeds are located, sticking to the leaves.

 Will the herbicide treatment to the water damage my boat or my dock? 

  A: No, the herbicide will not affect your boat or dock.

FAQs

I use the lake water as my main source for irrigating pastures or watering my landscape; will using treated water to irrigate harm grasses, shrubs, flowers, vegetables, etc.?

A: Yes, treated water can damage landscapes if it’s used during a restricted use period. Some of the herbicides used for treatment of water plants are the same kind of chemicals used for weed control on land.

How long after treatment will we be unable to use the water for pastures or landscapes?

A: Depending on the type and amount of herbicide, these restrictions could be for 3 days to 10 days. Lakeland Restoration Services will provide updates on water-use restrictions through our website and toll-free phone line so you know when it’s safe to use the water again.

What kind of restrictions can we expect if our water is treated?

A: Once the herbicide is in the water, the restrictions for water use will be in place. Restrictions can include:·

No human or livestock consumption (drinking)·

No irrigating pastures or watering landscapes (including gardens, lawns, and flower pots)·

No swimming for 24-hours (Washington State restriction)

Sometimes there are no restrictions, again it depends on the type of herbicide being used and how much is being used.

How do we find out when an area is being treated and if it’s under restrictions?

A: According to the NDPES (National Pollutant Discharge Elimination System) permit, which is required to do aquatic herbicide treatments, you will be notified multiple times before a treatment occurs in your area (for more information about NDPES permits, contact the Environmental Protection Agency; in Washington State, the Dept. of Ecology; in Idaho, the State Dept. of Agriculture).

A mailed notice of intent to treat water plants will arrive between a month to (2) weeks before a treatment. This will give you basic information about the aquatic herbicide treatment and a contact number and/or website you can go to if you have questions.

Two days (48-hours) before herbicide is applied to the water, your dock and/or shore line will be posted with a notice/ flyer that tells you what herbicide is being put into the water, what the restrictions will be and when treatment begins. Use this time to do your irrigation or watering of landscapes.

Then it will be up to you to use the toll-free phone line or website to follow the restriction updates after the herbicide is applied.