Waterford — As vandals continue to strike Harkness Memorial State Park, the Friends of Harkness volunteer group is growing concerned that repairs aren’t happening quickly enough.

Earlier this year, the friends group sounded the alarm after vandals smashed windowpanes and broke window frames three times in as many months.

Since then, Connecticut Environmental Conservation Police have responded to four other incidents at the park, according to Dennis Schain, spokesman for the state Department of Energy and Environmental Protection.

On May 23 around 5 p.m., a person or people with a crowbar or something similar tried to open one window of the iconic Eolia Mansion and successfully forced open another, damaging its frame.

On July 17 about 6:30 p.m., a park staffer discovered a door at the rear of the Carriage House, which is home to the park’s gift shop, had been forced open.

Nine days later, around 5:30 p.m., police learned someone had broken a window in the door of a small building near the mansion.

The most recent damage came within the past month, according to Eileen Grant, a past president of Friends of Harkness who now is active with Friends of Connecticut State Parks.

Schain said a report for the most recent incident wasn’t yet available. A trip to the park revealed many windowpanes at the rear of the Carriage House are broken or missing. None of the windows is boarded up.

In an email, Grant said the friends group is concerned the building’s current state could lead offenders to damage other buildings on the grounds.

“The worse Harkness looks, the more likely it will attract further criminal activity,” she said.

According to Schain, DEEP is in the process of putting final approvals and contracting in place for a project to repair all of the damage, including that which happened in the spring.

The project, Schain said, should start within the next few weeks. He didn’t yet have an estimate for the cost of the repairs.

Grant said such repairs are complicated because of the historic nature of the buildings. Contractors who qualify must be specialized, prepared to deal with lead abatement and other issues.

She said the damage sustained this year could cost up to $100,000 to fix.

It wasn’t immediately clear where that money would come from, although a likely source is the mansion’s wedding rental account. It has been used for years to help with maintenance and upkeep costs.

In addition to urging DEEP to expedite repairs at the park, the Friends of Harkness also called on the agency to enhance security there.

Grant said there’s a plan to install security cameras on the grounds’ primary structures, but they aren’t there yet. In the meantime, she said, adding more employees would be ideal and likely cheaper than the cost of further damage.

“We are brokenhearted that senseless vandalism is undoing our past work, undercutting our chances for planned future restoration projects and leaving park visitors under the impression that Harkness is a neglected and inadequately maintained state property,” Grant wrote.

Schain said while “it is virtually impossible to stop determined criminals,” the park is “taking steps to increase the vigilance and strength of our oversight of these buildings.”

Not wanting to compromise the park’s strategies, Schain wouldn’t clarify what those steps entail.

l.boyle@theday.com