The phrase "a single municipality" is correct and usable in written English.
You can use it when referring to one specific city or town that has its own local government.
Example: "The new policy will only apply to a single municipality, rather than the entire region."
Alternatives: "one municipality" or "a sole municipality".
Sekondi and Takoradi, a single municipality since 1946, became one city in 1963.
The two parts were not united under a single municipality until 1715.
"Civic committees", local parties formed by local people to contest just a single municipality, already hold 22 of the 330 mayorships.
"Until last year there was really no finances available for those repairs and the repairs were often beyond the resources of a single owner or often a single municipality.
When open space does go on the market, even when it's a large amount of land, it often only involves a single municipality and is ignored by residents of other communities.
By the early 17th century the name London began to embrace both the City of London and the City of Westminster as well as the built-up land between them, but the two never merged into a single municipality.
At that time I tried to get help from the county, largely because I saw it not as a single-municipality issue, but a much broader, and overlapping, area concern.
An exception is a survey within one single municipality as each municipality has the rights to draw samples from its own BRP.
Rob Ford's popularity is linked to the 1998 amalgamation of the six municipal regions of greater Toronto into a single city municipality.
Specifically, each polygon belongs to a single biome, municipality, vegetation type, soil type, and land use/cover.
In addition, big brown bats (Eptesicus fuscus) were sampled at 5 different sites (sites #17 21) within a single urban municipality in Northern Colorado Fort Collinss) during the summers of 2007 and 2008.
