A year after the Tisbury conservation commission discovered what it called the worst wetlands violation in decades, the town board, as well as the state Department of Environmental Protection, have come down hard on a West Chop homeowner responsible for dredging 11,600 square feet and filling in 1,235 square feet of wetlands at Mink Meadows Pond without a permit.

Stiff state fines along with the cost to restore the wetlands could cost the property owner, Mary Howell, of Arlington, Va., and Vineyard Haven more than $100,000. State environmental officials said they have not yet decided whether to fine the contractor who did the work.

Last February Tisbury conservation commission agent Jane Varkonda was alerted by neighbors to unpermitted dredging work as well as a large pile of fill that was accumulating on what had been freshwater marshland at Mink Meadows Pond. The work had been carried out by contractor Steve Handy on behalf of Ms. Howell. In addition to the damage done to the wetlands, a survey of the area also revealed that most of the work was done off Ms. Howell’s property, on lots owned by two abutting private property owners. Ms. Howell’s property does not abut the pond. Last year local wetlands consultants told the conservation commission that Ms. Howell had approached them, inquiring about requirements for dredging prior to the work. Mrs. Varkonda said the work was done in clear violation of the Wetlands Protection Act.

At their meeting on Tuesday the conservation commission voted to approve an order requiring Ms. Howell to restore, refill and replant the wetlands, as well as to require her to put $70,800 in an escrow fund to complete the work in the event she defaults. Ms. Howell was not present at the meeting and Mrs. Varkonda said she has never met her.

On Thursday Mrs. Varkonda said the escrow amount would have to be amended to include the cost of work to control the invasive plant phragmites in the area, as well as to include the cost of hiring a qualified wetlands specialist to oversee the project. She said those additions would likely add tens of thousands of dollars more to the cost of the restoration.

In addition, on Thursday, Massachusetts DEP spokesman Ed Colletta said his department had just issued an $11,650 fine to Ms. Howell that day, half of which would need to be paid in 30 days while the other half would be suspended for three years. The remaining amount would not be levied if Ms. Howell complies with the town conservation commission. He said the state department had not yet decided whether to fine Mr. Handy, the contractor.

Mr. Colletta explained the heavy penalties.

“The problem here was that she and her contractor did this work without any kind of local or state approval,” he said. “Wetlands are very important areas. They’re a very important habitat for various species including endangered species, they’re also very important areas for storm runoff and they help with flood management. They’re just a very important resource area that needs to be protected.”

Mr. Colletta said the state handles hundreds of wetlands violations a year.

As part of the Mink Meadows Pond wetlands restoration Ms. Howell will need to install siltation barriers around the affected areas and slowly reintroduce the excavated fill to the pond, while carefully avoiding filling in other parts of the pond, before replanting work can take place. Even after the work to restore the wetlands is finished, the conservation commission will continue to monitor the site for two years. If less than 75 per cent of the vegetation has grown back by that time there will need to be additional work to remedy the habitat.

While the price tag for the restoration work is high, in a recent conversation Mrs. Varkonda said the steep fines were not necessarily a deterrent to future violations.

“We just saw one today where someone had done something similar but on a smaller scale in Edgartown Great Pond,” she said. “And it was a repeat violator.”