When you hear the phrase island city, you probably don't think about Santa Rosa.

Yet there are more than 50 "islands" — pockets of unincorporated Sonoma County — within Santa Rosa's city limits.

The largest, of course, is Roseland.

But as the city expanded to the west and southwest, it hopped over vacant land, mobile home parks and the edges of several neighborhoods. In some areas, homes on one side of a street are in the city while those on the other side are in unincorporated territory.

A handful of county islands also can be found on the east side of town.

This all may seem trivial — the difference between being shaded yellow or white on a map of Santa Rosa. In fact, it does make a difference. It has a direct impact on the delivery of public services and, in turn, the efficiency of public agencies.

For at least 17 years and probably longer, the county commission that reviews annexations has pressed Santa Rosa to take in these islands, especially those with fewer than a dozen residents.

Public services in those areas are provided by the Sheriff's Office and other county agencies as well as various special districts whose primary service areas are elsewhere.

In an emergency, mutual aid agreements ensure a response from the nearest police officers or firefighters. But who do residents call about a remodeling permit or a pothole?

The county Local Agency Formation Commission recently renewed its push for Santa Rosa to annex the smaller islands. Under a new policy, Santa Rosa cannot annex only a portion of islands with fewer than a dozen registered voters. That covers about a quarter of the 51 county islands in the city.

Santa Rosa officials balk at the cost of adding land and residents to the city. Cost, indeed, is a factor, as evidenced by the lengthy negotiations over annexing Roseland. Yet it's also true that Santa Rosa wasn't in any hurry to annex Roseland or any of the smaller county islands when the city was expanding elsewhere.

Some members of the commission favor a tougher approach — requiring annexation of entire islands up to 150 acres. That may have been too large a burden to place on the city at this time, but Santa Rosa needs to be more proactive on this issue.

Sonoma County Supervisor Efren Carrillo, who represents Roseland and west Santa Rosa, delivered a blunt message at the LAFCO hearing 10 days ago: "I don't think the city has done an honest job in at least identifying what their long-term trajectory is."

Chuck Regalia, Santa Rosa's director of community development, said that would require a shared effort by the city and county to arrange a large annexation such as Roseland. OK, and it would be sensible to take that same approach with the smaller islands, too.

There's no better time to start than now.