BELGRADE — State officials are warning boaters this Memorial Day weekend of a temporary ban on boats that will be enforced on Great Meadow Stream and a portion of Great Pond while volunteers work to rid the area of an invasive aquatic plant.

The popular waterway has an infestation of variable leaf milfoil, which can overtake natural habitat in a lake. Environmentalists say it is easily spread by tangling in boats’ motors and other equipment.

The Department of Environmental Protection, with assistance from the Maine Department of Conservation’s Boating Facilities Division, have put out buoys labeled “area closed” marking the southern boundary of the restriction.

Samantha DePoy-Warren, spokeswoman for the DEP, said the restriction extends from where Route 225 crosses Great Meadow Stream in Rome and Smithfield south into the northern portion of North Bay in Great Pond. The ban went into effect last month and will continue through Sept. 21.

DePoy-Warren said watercraft may not enter or travel the waterway except in an emergency or when state officials and volunteers are in the process of surveying or removing milfoil.

Starting Sept. 22, non-motorized watercraft, including kayaks and canoes, will be allowed in the waterways, but motorized craft will be prohibited through the year’s end, she said.

DePoy-Warren said it is hoped the restrictions will limit the spread of milfoil, which accounts for 17 of the 23 infested lake systems documented in Maine.

The restriction also will allow DEP staff and volunteers from the Belgrade Lakes Association and Belgrade Regional Conservation Alliance to remove the plants safely.

John McPhedran, director of the state’s Invasive aquatic plants program, said surface-use restrictions are rarely used but can be an integral tool to tackle invasives and their devastating impact.

“We are confident that this short-term inconvenience will have a long-term payoff in protecting Great Pond’s water quality, habitat for native fisheries and wildlife, recreational opportunities and values of lakefront property,” McPhedran said.

The state also has a surface-use restriction in place on Davis Stream in Jefferson to stop the spread of invasive hydrilla into Damariscotta Lake. DEP and volunteers from the Damariscotta Lake Watershed Association are working to remove that plant.

DePoy-Warren said the most effective prevention effort continues to be the state’s Courtesy Boat Inspection Program. The Lakes Environmental Association and the Maine Congress of Lake Associations has been contracted by the state to train volunteers and organize the statewide inspection program.

She said trained inspectors conducted 76,105 inspections on 116 waterbodies in 2011, making 287 saves that stopped the spread mostly of variable leaf milfoil plant fragments. She said boaters should inspect their boats and equipment before and after use.

Boaters should check for and remove plant debris from the anchor, lines, live well, bilge, motor prop, all fishing gear and their trailer and related equipment including the hitch, trailer axle and license plate, she said.

Mechele Cooper — 621-5663

mcooper@centralmaine.com