An obstacle course featuring pools of water and waist-high mud is slated to return to Old Bethpage Village Restoration next summer, upsetting preservationists but buoying Long Island’s tourism boosters.

Preservationists had worried that the August 2015 Tough Mudder — the first held on Long Island — would damage the 209-acre re-creation of a mid-19th century Long Island village, which includes 51 historic buildings.

There appeared to be no damage, but Natalie Naylor, president of the Nassau County Historical Society, urged the county to move the event elsewhere. “I’m distressed they are returning,” she said.

Robert MacKay, former director of the Society for the Preservation of Long Island Antiquities, said an obstacle course “is an inappropriate activity for this open-air museum, which has been the focus of so much effort over many decades by so many people.”

In August, participants ran past some of the historic buildings, slogged through mud and swung over a pool of water created for the event by digging a hole in the ground. The county required Tough Mudder to restore the site to its pre-event state. The village was closed to the public during the event.

Mary Studdert, spokeswoman for the Nassau County Department of Parks, Recreation and Museums, said Tough Mudder “organizers have proved their respect for the village’s assets” and the county will not move the event, which boosts the Island’s economy.

advertisement | advertise on newsday

The two-day event, which attracted about 8,000 participants to the 10-mile obstacle course, pumped $2.5 million into the Long Island economy through spending in the region’s hotels, restaurants, gas stations and other businesses, said Jennifer Rothman, sports sales manager for the visitors bureau.

Brooklyn-based Tough Mudder, which in 2016 expects to hold more than 60 obstacle-course events in eight countries, also makes Long Island attractive as a potential destination for other money-generating events, Rothman said.

Tough Mudder is a challenge rather than a race. There are no awards for finishing first. Participants often rely on each other to get over a wall or for encouragement, said Fernanda Borgogelli, 39, of Franklin Square, who participated in the August Tough Mudder and said she was excited to hear it would return in July.

“It’s all about a team effort,” she said. “You’re there for each other. It doesn’t matter if you’re weak or strong.”

This year’s Long Island event will feature a regular Tough Mudder — usually about 10 miles — on July 23 and a 5-mile version of the course, Tough Mudder Half, on July 24.

Tough Mudder will pay Nassau County $50,000 to hold the 2016 event at Village Restoration, up from $30,000 for the August event, Studdert said. That money allows the county to invest more in the village, she said.

Tough Mudder handled security at the obstacle course. But county police spent $6,134 for traffic control and security near the venue, police officials said.

Kate Fitzpatrick, vice president of community development and venues for Tough Mudder, said in an email that Tough Mudder did not request the police presence, and the county did not request reimbursement.