LIKE many folk who live in or near Edinburgh, I am shamefully less familiar with its main attractions than a Japanese or German visitor who is only passing through. Normally I avoid the honey pots where tourists throng, preferring to make my way across the city by back streets and vennels known only to those who have padded around these parts for years. On Saturday, however, I happened to find myself in two prime guide book locations – St Giles Cathedral and John Knox’s House. Both are on the ancient Royal Mile, where tourists outnumber the cobbles.

The scene might have been specially staged as a variation on the experiment of how many people can be fitted into a phone box. Queues of visitors were gawping at the cathedral’s vaulted ceilings and squeezing into Mr Knox’s low-beamed home, while outside thousands were milling the streets. From what I could see, they were from virtually all parts of the world, America and Australia, France and Fiji, and countries I couldn’t even guess at.

These recent arrivals, and those who will follow in increasing numbers as summer advances, are part of the seasonal influx to the capital that is as predictable and clockwork as the migration of long-distance birds. Summer sees them land in the greatest number, but Edinburgh these days is rarely empty. The year kicks off with the Hogmanay celebrations, which come close on the heels of the Christmas fair, and is followed by Easter and summer, before a tsunami of festival-goers descends in August. The idea of a defined tourist season, after which shutters are drawn and tumbril weeds roll down the street, now seems quaint. It’s not quite an all-year party, but it’s heading in that direction. And if the council has its way, hospitality and the guests who feed it, will soon be the capital’s raison d’etre.

In the weekend sunshine, Edinburgh’s Old Town was looking pretty good. How long it will remain that way, however, is uncertain. There are only so many visitors this tiny metropolis can accommodate before something gives. For many years, the place has been straining at the seams like a fat man’s jacket whose buttons are starting to fly off. Except with the city, the consequences will be far more serious than a trip to the tailor’s or a crash diet.

As one of Europe’s most enchanting capitals, Edinburgh has been hymned for centuries for the glories of its architecture and location, and the cultural delights it offers. Much has been said of late – and clearly a great deal more outcry is needed – about desecration by cynical and greedy planning approval of buildings so inappropriate they should have no place in its skyline. That, however, is a rant for another day. An equally pressing issue, and one that affects everyone who lives and works here, is the quality of life in a tourist haven where the needs of incomers seem sometimes to take precedence over those who pay council tax and business rates.

In parts of the town the state of roads and pavements is more like something you’d expect on the Karakoram Highway than near the seat of our parliament. Litter strews the streets and spills out of bins, followed by scavenging seagulls. Traffic congestion makes commuting a headache, and many buildings, flats and commercial properties are in such disrepair, they are an eyesore. Meanwhile, the mess in the wake of festivities is so unsightly, it’s as if teenagers had been left alone in charge of the city while we were gone, and issued a party invite on Twitter.

All of these are practical matters, but they are also aesthetic. As the landscape of Edinburgh frays at the edges, so does its appeal. It is astonishing how quickly charm can turn to tawdriness, elegance to decay. Locals’ patience also swiftly wears thin. Mine, for one, is threadbare.

A report last week showed an impressive 63% of residents and businesses are prepared to contribute towards the upkeep of the city and its major attractions. As if they don’t already give enough. Their generosity, however, was bettered by that of tourists, 71% of whom said they were prepared to pay up to 26% of their daily spend towards the maintenance of this world heritage centre.

Surely, then, there is no argument left against the tourist tax, about which Holyrood remains distinctly tight-lipped. George Osborne’s budget speech in March made it clear that the so-called “Edinburgh deal” – which includes East, West and Mid Lothian, Fife and Borders – was firmly on the table. The details of what this micro-devolution means have yet to be made public, or indeed to be resolved. So there is no better time, surely, to urge that Edinburgh uses its newly granted autonomy to lead the way as the first British city to impose a hotel tax, and to encourage Holyrood to embrace that concept. After greeting the proposal of a levy five years ago with froideur, the Scottish Government no longer has any excuse not to consider it seriously. Even to untutored eyes the city’s funds for upkeep and renewal are badly in need of a boost.

Nor would it be a radical move. Across Europe, such a tariff is common. Rates vary, but the principle remains the same. Whether you’re in a five-star hotel in Berlin or a B&B in Umbria, you will pay a small amount per person, per night, from 1.50 euros to five, usually for only the first week of your stay.

Best of all, these proceeds go not to the hotel but to the town. It is thus essential that if Edinburgh adopts this levy, as one dearly hopes it will, all proceeds are ring-fenced for the capital’s use.

This tax must not subsidise tourist events, or become a backdoor source of festival funding, or be subsumed by cultural projects whose cash has run out. It must be spent on the bricks and mortar, the nuts and bolts, of keeping Edinburgh in the manner to which it is accustomed. In other words, for doing what is necessary to make Edinburgh great, for everyone. Citizens who never see the Bolshoi in August, or step over the door of the Book Festival in Charlotte Square, or traipse up to the castle, must see and feel the benefit. After all, it is their home that attracts incomers. If their environment is not well cared for then nor, in time, will visitors be as welcome or well-treated.

You could view a tourist tax as like a dripping roast. It will provide a steady, mouthwatering stream of revenue (an estimated £15m annually) that, if it does not exactly pave the streets with gold will replace missing kerbstones, fill potholes, improve traffic flow and air quality, and provide more litter bins and refuse collections.

And unlike in Europe, guests who stump up a very modest sum will find on their doorstep world-class art galleries and museums. In many of their home countries, entry would cost more than a week’s levy but in Scotland they are entirely free. From whatever angle you look, everyone benefits. Name another tax that would make so many people smile.