WASHINGTON — The National Park Service has for decades allowed members-only beach, yacht, and sports clubs — including New York City’s largest beach resort — to “monopolize” public lands that by law should be open to all, an Interior Department audit shows.

The audit also found that the Park Service failed to consider “environmental consequences” for 18 of 20 sites included in the survey.

The clubs “have enjoyed exclusive rights to public lands through restrictive and costly memberships that deny the general public the same benefits,” the report reads. “In some instances, the National Park Service has authorized this exclusivity for 30 or more years.”

The Washington Canoe Club in Georgetown and the Breezy Point Surf Club in Queens are among the private clubs occupying waterfront land, the survey by the Interior Department inspector general’s office found. Park service officials acknowledge the problems but say they have no idea how many private clubs occupy public land under so-called “special use” permits. A sampling of parklands for the audit turned up five private clubs occupying scores of acres on the East Coast, three in New York, and two in the Washington area.

An Interior Department inspector general’s audit in 1984 raised the same questions as the latest audit, but the park service did little to address them, despite officials saying then that they would take action.

National Park Service director Mary Bomar “has committed us to find out the extent to which these special use permits limit public access, and not to renew any special permits until she can make a determination on whether they limit public access to these areas,” said park service spokesman David Barna.

“It’s going to take us some time,” he said. “We have 391 parks on 84 million acres and we’re going to look at every one.”

Senator Grassley, who is a Republican of Iowa, the ranking member of the Finance Committee, and a longtime agency oversight advocate, also plans to examine the issue.

“The Interior Department appears to be taking the public out of public lands,” he said. “Taxpayers shouldn’t be subsidizing swimming pools, beachfront property and canoe clubs on taxpayer-owned land for the exclusive few who can afford to pay the membership fee.”

All of the clubs in the audit occupied their locations at the time the land they are on was turned over to the park service. The park service’s Mr. Barna said that, when the agency acquires land, it deals with existing occupants in a variety of ways but parkland must be open to all.

“It’s going to be a case-by-case basis. This is not going to be easy, which is why nothing was done in 1984,” he said.

A reassessment could bring changes for the Washington Canoe Club, whose special permit expires this year.

Located in a century-old boathouse on fenced-off Potomac riverfront land in Georgetown, the club’s membership is restricted to 200. The club trains sprint canoe and kayak racers, and has sent a competitor to nearly every Olympics since 1924. Its property was ceded to the park service in 1971, according to the audit.

Membership requires two sponsors, a personal interview and a board vote. The club’s fund-raising arm raised more than $20,000 at an auction last year. The club’s annual payment to the park service is $5,000, the audit says.

“I would like to negotiate a reduction in the lease, because we’ve got a lot of things we’re trying to do programmatically at the club,” which recently hired a coach from Poland, said club president Andrew Soles.

He said public access would not fit the club’s mission. “We want to be the center in the U.S. for sprint and kayak racing,” he said. “We don’t want to become a rental-of-aluminum-canoes place … that sells people lemonade down by the river.”

Two of the biggest New York beach clubs, Breezy Point and Silver Gull, located in the Gateway National Recreation Area on the Rockaway peninsula in Queens, operate on special use permits dating from the 1970s. Both clubs were singled out in the 1984 report questioning their exclusive use of large swaths of parkland, but they have remained private.

The park service has renewed permits for those clubs, as well as nearby Rockaway Point Yacht Club, for more than 30 years without the legally required environmental reviews, the audit said. Among the environmental concerns the park service failed to consider were waste disposal, hazardous material storage and the impact on the park’s plants and animals of the more than 3,000 people who are members of each club.

Breezy Point Surf Club occupies 60 acres of prime oceanfront land in the park. According to its website, the club “offers acres of pristine beach area for roaming and relaxation,” as well as an Olympic size and kiddie pool, playgrounds, mini golf, and playing fields.

Breezy Point pays the park service $340,000 yearly, about one-tenth of what it earns. A summer membership for a family of four is $1,500, and requires renting a bath cabin or cabana which range from $400 to more than $4,000 for the season.

The Silver Gull Club celebrates “Our 34th Year of Fun in the Sun with the National Park Service” on its website. The club features four pools with water slides, water aerobics to meditation classes, a poolside patio bar and free day camp. Summer membership for a family of four starts at $2,200, plus a changing cabin or cabana, which ranges from $700 to more than $4,000. The club pays one-tenth of its $3 million in revenues to the park service.

The Rockaway Point Yacht Club’s permit expired in 2004, the audit said. The club continues to pay the park service $500 a year, the same rate it charges each of its 100 members.

Managers at the three clubs could not be reached.