Like an island, the Potomac properties are surrounded by Rockville land.

The 7.9-acre enclave is the last of its kind within the municipality.

Amid annexations — a process to enlarge the city’s corporate boundaries and align municipal borders with property lines — two properties on Hectic Hill Lane have avoided incorporation for decades.

“I suspect that they perhaps didn’t see the benefit,” Jim Wasilak, Rockville chief of planning, said of the individuals who owned the property in the 1980s when annexation discussions began. “They would be paying additional property taxes in the city with perhaps no apparent increase in services.”

Generally, annexations are petitioned from property owners, Wasilak said. The city benefits from the moves because they give the city planning and zoning control, he said. The city annexed four properties within the past year and has no pending annexations.

In 1983, the state prohibited the creation of new enclaves; the Hectic Hill enclave, which consisted of more than two properties, was created in the 1970s, Wasilak said. At the same time, the state provided for municipalities an easier process to annex existing enclaves.

“The city, at that time, initiated annexations on seven of our enclaves that existed then, including this one,” Wasilak said.

A year later, owners of 8311 and 8321 Hectic Hill Lane testified against annexation before the Rockville mayor and city council.

The other six existing enclave properties were annexed into the city, along with other properties on Hectic Hill and two abutting properties that existed as part of the enclave.

The property owners at the time, John Voegtly and Lacey Gude, opposed annexation because taxes would rise, according to transcripts from a 1984 public hearing. They received services such as trash and garbage collection and police and fire protection from Montgomery County.

Annexation would result in an annual increase in ownership costs of $1,488, from $12 to $1,500 per year, because Rockville property owners need to pay city taxes and for trash collection and water and sewer access. (The properties have self-contained water and sewer systems.)

In this case, the city was trying to eliminate the enclaves.

The Hectic Hill property owners argued their land acted as a buffer between housing developments along Fallsmead Road, Horizon Hill Park and Potomac Bend.

“Rockville is becoming increasingly more densely populated, and there are all too few remaining residential green areas,” Voegtly told the council in 1984, according to a public hearing transcript.

He ran the property as a farm, raising horses and breeding game birds.

“I certainly don’t want to see it being added to subdivisions which you are saying you might be pressured into if it is annexed,” then-councilwoman Viola D. Hovsepian said.

The properties — valued at $1.2 million and $1.5 million, according to state property records — look much the same today. Hectic Hill sits tucked off Wootton Parkway, a wooded oasis adjacent to a main thoroughfare.

Claire Zhang, the current owner of 8311 Hectic Hill, said she hasn’t thought much about whether to annex into the city.

“We are new,” she said, noting that her family has been living in the house for about four years.

The owner of 8321 Hectic Hill could not be reached for comment.

Annexations require an application through Rockville’s department of community planning and development services. The Rockville mayor and council need to approve annexations with a majority vote.

The 1984 council, led by mayor John R. Freeland, decided to allow Voegtly and Gude to keep their properties as part of Montgomery County.

That island still appears on Rockville maps.

“You have no idea what that adds to the community,” Sue Eckstein said at the 1984 public hearing, referring to the two Hectic Hill properties. “You can walk through there. You can [breathe].”