Are the weeds worse than usual this year? Experts say no.

Maybe all those weeds in the lake aren’t as bad as they seem.
As Fred Lubnow and Chris Mikolajczyk of Princeton Hydro, along with Donna Macalle-Holly of the Lake Hopatcong Commission, prepared to launch from Hopatcong State Park to check water quality samples around Lake Hopatcong on Tuesday morning, they were expecting the worst.
“Usually Donna and I don’t join Chris for an assessment until July or August,” Lubnow said. “But after all the talk at last night’s [Lake Hopatcong] Commission meeting, I’m glad we’re getting out here before the weed harvest begins, to get a sense for just how bad things are.”
Several hours later, Lubnow felt better about the weed situation on the lake. “Overall, for all the sites, it’s not as bad as we thought it was going to be,” he said.
That’s not to say that the concerns of residents—such as Charles Morel of Woodport, who complained about wall-to-wall weeds in front of his house at the Lake Hopatcong Commission meeting on Monday—weren’t warranted.
“There definitely were some spots with high densities of plants, and mat algae on top of that,” Lubnow said. Specifically, he pointed to the northern end of Woodport (where Morel lives), a small cove called Shallow Cove (just west of Hurd Cove in Lake Hopatcong), and River Styx, particularly in the “T” area.
But aside from those three locations, Lubnow said, all of the sample stops only showed light to moderate aquatic plant growth.
“Obviously there will be more plant growth as we go through the season,” he said, adding that, come summertime, the higher water temperature and increased amount of light will cause more rapid weed growth. Other factors that might have contributed to an increase in weeds in those trouble spots include a very rainy spring that brought runoff into the lake, and a reduced weed-harvest effort in recent years because of a lack of funding.
Water monitoring of Lake Hopatcong goes back to the late 1970s and early 1980s. In 1983, the Lake Hopatcong Regional Planning Board secured funding to do a phase I diagnostic study of the lake, in part to determine the sources of pollution and problems, so that the board could work toward solutions to find them.
“Lake management,” Mikolajczyk said, “is not just about treating the symptoms, but also about treating the causes.”
Those were put into a restoration plan, and Lubnow said all activities since then have been based on that plan.
Another plan was created in the early 2000s, but did not include an aquatic plant survey. Last year, the Lake Hopatcong Alliance used money from its I Boat NJ grant to conduct such a survey, which incorporated more than 500 data points. “When you compare the survey of the 80s to the survey of last year, there really aren’t major differences, and there is no indication that the weed harvest effort has spread the weeds,” Lubnow said. “The two dominant weeds continue to be Eurasian milfoil, a non-native plant, and tapegrass, a native species.”
Consistent water-quality monitoring of the lake has been in place since the 1990s. “That’s a pretty rare thing,” Lubnow said. “But it’s really important, both to be able to identify how the lake is doing when people ask, and to track development of various restoration projects and identify how the lake is responding to them.” That also helps, he said, when trying to secure funding for future storm water and other restoration projects. “It’s really a cyclical thing.”
Initially, the Lake Hopatcong Commission paid for the monitoring through its operating budget, but in the last couple of years, the state has funded the effort through DEP 319(h) grants; the commission and Princeton Hydro are in their second year of a three-year monitoring plan. Macalle-Holly said that financial support—which includes monitoring, a year-end report, and assessments—comes to about $18,000 per year. “So it’s not accurate when people say that the state isn’t doing anything to fund the lake,” she said. “They’ve continued to fund this.”
For Tuesday’s monitoring trip, the trio took a Princeton Hydro outboard motorboat to 16 different sites around Lake Hopatcong, including five sites that are close to the shore and specifically tied to restoration projects that have been completed. Each stop involved a series of water-quality checks, including dissolved oxygen, temperature, pH level, conductivity, water clarity, and total suspended solids. Princeton Hydro also checks phosphorus levels, since it is the nutrient most linked to aquatic plant growth, and chlorophyll A, which is a quick way to determine algal biomass.
Through the years of conducting these tests while simultaneously completing storm water projects, the water quality on Lake Hopatcong has steadily improved, and phosphorus levels have not increased in the last four or five years, Macalle-Holly said.
The monitoring station consistently with the lowest quality has been the River Styx station. “It’s not rocket science,” Lubnow said. “You look at the topography and the development and you can see why.” That area gets a rush of nutrients into the water every time it rains.
On Monday, the Lake Hopatcong Commission approved a plan to fund the weed-harvesting effort for the month of July, potentially using the last of the money in the commission account to do so. In addition, with the guidance of Princeton Hydro’s weed survey, the Lake Hopatcong Alliance is conducting two alternative weed-control options, including a weevil project near Lify Island and a bioraking project in Bright’s Cove.
Lubnow and Mikolajczyk said other options, such as chemical treatment or dredging, would be much more pricey without guaranteed results. “To treat Lake Hopatcong with chemicals, it would cost a tremendous amount of money,” Mikolajczyk said, adding that the treatment’s success is also very dependent on uncontrollable conditions, such as rainfall.
Macalle-Holly said that the commission’s official stance is to discourage chemical treatment, but she can provide a list of certified providers for those who are seeking it. (To read a full story on chemical treatment, click here.)
Watching the team conduct its first survey from the dock at Hopatcong State Park, Hopatcong resident Ted Glogiewicz said he was glad to see efforts under way on behalf of the health of the lake.
“Up in Woodport and over in River Styx, those weeds are some of the worst I’ve seen,” he said. “And I’m on the lake every day.”
For now, lake residents such as Morel and Glogiewicz can expect to see the weed harvesters on the water in the coming days, and know that Princeton Hydro will continue its regular monitoring in the coming months. And aside from those trouble spots—which are likely to get immediate attention from the harvesters—the weeds are on par with what the lake community has faced in the past.
“The weeds are going to increase as we go through the growing season,” Lubnow said, “but at least for not it’s not as bad as we thought.”