Rosie Hartzler, president of the Highland Lake Association, kicks off the group’s annual meeting on July 18. Jane Vaughan / Lakes Region Weekly

WINDHAM — Although an algal bloom has not appeared at Highland Lake this year, experts are still concerned about the long-term health of the 640-acre body of water that straddles Windham and Falmouth.

About 70 people showed up for the Highland Lake Association’s annual meeting. Jane Vaughan / Lakes Region Weekly

The Highland Lake Association, which was formed in 1989, is a nonprofit dedicated to preserving and protecting the natural resources of the lake and its watershed.  At the group’s annual meeting on July 18, experts and association members presented information about the lake’s progress over the past year and the nonprofit’s goals going forward.

“In the past couple years, we have greatly increased our intensity of testing and expanded that program,” HLA President Rosie Hartzler said at the meeting, which was held at Cornerstone Church on Cottage Road.

During an update on the lake’s water quality, Dr. Karen Wilson, an associate research professor of environmental science and policy at the University of Southern Maine, said, like previous years, she expected a full-blown algal bloom this year, but “it didn’t happen.”

She and her team of researchers have been collecting data on a variety of variables, including water clarity and the amount of phosphorus in the lake. They are now investigating what caused past algal blooms and why one did not occur this year.

In addition, Wilson said, because this spring was wetter and colder than last year, it affected how the lake warmed up and when the alewife population arrived.

“The bottom of the lake is warmer this spring,” Wilson explained, meaning there is less dissolved oxygen for the fish.

“The objective really needs to be keeping phosphorus levels down. Without that phosphorus, you can’t have an algal bloom,” she added.

Wendy Garland, an environmental specialist at the Maine Department of Environmental Protection, provided an update on the watershed’s management plan at the meeting.

The plan is being developed after conducting a watershed survey in 2018 that involved surveying 129 sites around the lake, as well as a septic system survey and an assessment of other possible sources of pollution.

The survey, Garland said, “was really a key first step of getting a handle on watershed phosphorus sources.” The sites that have the highest impact on Highland Lake are private roads.

Now, she said, the goal is to make “a plan that we can all follow over the next 10 years, 20 years.” She hopes the plan will be completed by the end of the year.

As part of the watershed management plan, the technical advisory committee has developed six strategies that will help reduce the amount of phosphorus going into the lake, explained Heather Huntt of Cumberland County Soil and Water Conservation District.

Those strategies include fixing the problem sites, reducing the impact of septic systems, maintaining the roads, preventing new problems, maintaining ongoing support and water quality monitoring.

The lake “needs ongoing work, it needs you, it needs a lake association heavily involved, it needs a community heavily involved,” Huntt said.

HLA Treasurer Dennis Brown added that although the association’s budget for this year is lower than last year’s, it is still more than $8,600 short of its fundraising goal.

“If you like what you see, please help us out and get us over the top. It’d sure be nice if we could wrap that up,” he said.