Perennial potholes.

IT'S springtime in New England and the flowering trees have blossomed out everywhere. And so have the potholes.

Well, not quite everywhere. Some communities are bringing the problem under control, including this prosperous university town not far from Portsmouth.

Civil engineers and public-works directors are proclaiming the gladdening news that chronically potholed roads are not an inescapable fact of life in a cold climate.

''Road systems management,'' if you can excuse the jargon, is catching on in public-works departments. The two key features are an emphasis on preventive maintenance rather than pothole patching, and a systematic survey of all a community's streets. The survey is often computerized and usually involves a numerical-rating system - 1 to 10, for example - for the roads. This method enables towns to do roadwork systematically rather than reactively. (''Mr. Mayor , you wouldn't believe the size of the hole in front of my house.'')

And spending some money up front lets towns save a lot of money a few years down the line.

If the money that driving over poor-quality roads costs motorists - in tire wear, auto damage, reduced mileage, and so on - were spent up front to build new roads or reconstruct old ones, ''we could have a good-quality road system for substantially less - and I mean substantially less - than we spend now to get a crummy system,'' says Lynn H. Irwin of Cornell University. Bad roads are, in effect, an indirect gasoline tax of 40 cents per mile, he says, citing figures from The Road Information Program in Washington.

The problem, though, is that roads are most cost-effectively treated when they don't look all that bad to the average citizen - at least not when the firefighters want a raise and the schoolteachers are fed up and the town library has had to cut back hours.

An asphalt overlay, applied to a well-built street in fairly good condition, can extend the life of the street by as many as 15 years, according to Professor Irwin. Price tag: $65,000 a mile. But past a certain point, roads deteriorate quickly. If the overlay is put off too long, it will be less effective, or ultimately, completely useless. The road may be so far gone that there is no way to take care of it short of reconstruction. Price tag: $650,000 per mile.

If a road is seriously potholed, it's too late, civil engineers say. There's nothing to do but dig it up and start over. The road is, in effect, a membrane, like the ''web'' on a cup of hot chocolate. When potholes appear, it's a sign the membrane's surface tension has been destroyed.

At a time when every public dollar is turned over and looked at hard two or three times before it's spent, the professional systems-management approach has to include some politicking.

George Crombie, public-works director here in Durham, has his own ways of making points. ''We rent a bus and load it up with the members of the planning board and drive them over to some of the neighboring towns. We take them through some of the subdivisions there, where the roads are falling apart after just a few years, and we ask them, 'Do you want our roads to look like this?' and they say, 'No.' ''

He drives a visiting reporter through a subdivision in Durham, built in recent years, since the town instituted its strict standards for streets: 18 inches of gravel in the subbase, plus a three-inch asphalt overlay. His car almost floats along the unblemished asphalt.

A short distance away he pulls onto an older road. It wasn't built to the current standards but has been treated with a coating of stone chips which has improved the surface considerably. It's rougher than the first road, ''But we find that helps with traction during the winter.''

Then he moves across the town line to a subdivision built at the same time as the newer section over in Durham.

The difference is dramatic. As a result of inadequate underground drainage, sand has washed onto the roadway, which is already breaking up badly along the edges. It looks as if a dragon had ambled out of the woods, bitten off great chunks of the asphalt, chewed them up and, finding them wanting, spit them out again.

A chronic problem for growing communities is subdivisions where substandard roads end up costing the town more in street repairs than the houses generate in property taxes. Mr. Crombie and his colleagues argue before the planning board for high standards on subdivision construction, and if that makes Durham a more expensive town in which to build, so be it. ''We say to the developers, 'If you can't afford us, we can't afford you.' ''

Durham has some advantages that not every community in New England can match. It is a prosperous community, with the University of New Hampshire as its main industry. Property values are high enough so that even relatively low tax rates still generate comfortable revenues.

Durham started in the roads-systems-management approach some years back, after the university's dean of technology joined the public-works advisory council. Morale is high among the town's relatively large, professional, and well-paid staff because they know they are more than just pothole-patchers.

''On a stone seal, for example,'' Crombie says, ''you could just call up a contractor and say, 'Come do it for me and send me the bill.' But here we've got enough expertise in house to suggest how the mix could be put together cheaper, and save 40 percent on the job. Towns that keep public-works salaries low end up spending more in the long run.''

And the importance of community cohesiveness should not be underestimated. With 11,000 people, Durham is the kind of place where a bridal shower merits a write-up in the local paper; it is worlds apart from Boston, for example, with its geographically distinct neighborhoods and political rivalries.

Nantucket, Mass., is another illustration of how smaller communities can do things more easily. Local officials were tired of spending a quarter million dollars every year to patch the same potholes and decided to authorize $3 million for a major upgrading of the roads. The resort island - all of which is officially one town - commissioned the Boston engineering firm of Vanasse/Hangen to survey its 66 miles of public streets, which were becoming a detriment to the tourism on which the island depends.

After the survey came a plan to take care of the most critical needs first. As the projects were let to bid, particular care was taken to group them for economies of scale, to entice mainland contractors into bidding - which they did not when Nantucket was just patching. The bids for the first, smaller phase of the $3 million project in 1983, expected to be $545,000, came in at $408,000. Bids for the second phase, estimated at $3 million, came in in April at $2 million. ''I really enjoyed opening that bid,'' says James D'Angelo, an associate of Vanasse/Hangen. ''Everybody knows it was a good bid, but I don't know if anyone perceives just how good that was.''

But even while some towns are seeing the light on systematic management, others are having a hard time keeping up even longstanding policies of preventive maintenance - particularly in Massachusetts, under the fiscal restraints of Proposition 21/2.

Newton Sweet has been public-works director for the comfortable bedroom community of Danvers, Mass., since 1968. He is not optimistic about the town's prospects for being able to maintain its system.

He benefits from a generally businesslike attitude within town government, he says, and is able to spend his public-works budget as he deems fit, free of political pressure.

But local revenues are not keeping pace with inflation, despite general prosperity and the rise of the 2.5-car family. And Danvers is not keeping up with its maintenance schedule as he would like. Road reconstruction is taking second place to interim maintenance. ''But all we're doing is postponing disaster.''

The Danvers Public Works Department maintains the town's school buildings, so Mr. Sweet is particularly aware of the local young people here. And he worries what they will think a few years from now.

''It will be 1994, and all the parents who voted for 21/2 will be off retired in Florida or Puerto Rico or someplace, and the kids will point to me and say, 'Ten years ago, this guy used to do a good job on the streets around here. What happened?' ''