Light on muddy waters?

A Thames Strategy? Sounds impressive, visionary even. What's it going to do?

Transform the river from what the document describes as ''a barrier to movement, and a psychological dividing line between north and south London'' into a busier, more exciting, dramatic and useful part of the capital. Alas, it's far from clear that this transformation will happen.

Why not? This is an official government report, isn't it?

Yes. But strategy does not mean action plan. The document is 90 glossy pages of text, maps and photos that skilfully explain what's wrong with the Thames then set out broad proposals for improvement.

So why don't ministers get on with implementing those proposals?

This is London, not Paris. Mr Gummer is not about to announce fat new improvement grants and state-funded grand projets on the riverbank. What he has promised to do is produce strategic guidance later this summer for the City of London and 16 London boroughs strung out along the river. He has set up a Thames Advisory Committee with senior property developers, architects, planners and editors on board.

Strategic planning guidance sounds much less exciting than a Thames Strategy. What is it?

London boroughs decide whether proposed riverside developments win planning permission, with the Environment Secretary having powers to overrule them. This guidance sets out planning principles for these boroughs, telling them about the nature of new development the Government wants.

Aren't property developers the people who have done so much to disgrace the river with grandiose and appalling bankside buildings?

Yes, but they are the most important people in all of this. The Government looks to the private sector to lead the Thames renaissance by financing exciting multi-purpose developments - offices, homes and shops - on the many vacant and run-down riverside lots.

And will it?

Not for some time. The next property boom is still awaited and, as the Thames Strategy document says, ''there are relatively few signs of construction along the riverside". There are also masses of housing and office schemes that have been granted planning permission but not built.

Two buildings sum up this bleak state of affairs: the partly demolished Battersea Power Station and County Hall, which may be kept empty by its Japanese owner for years. The one that gives hope is Bankside Power Station, opposite St Paul's Cathedral and earmarked for a new Tate gallery.

So is all this just a vain appeal to property developers to come back and build better?

Well, Mr Gummer also wants ''exciting young architects'' and established ones to draw up proposals for some key sites, in the hope that their visions will inspire the property industry, councils and Londoners. The architect Sir Richard Rogers, a member of the new advisory committee, pointed out that they might want to be paid for their work. Mr Gummer was vague about this.

But let's not be too pessimistic about the Thames Strategy and put its fate entirely at the whim of architects and developers.Central and local government are important players, through their power to approve schemes and through the hundreds of millions of pounds available in various urban regeneration funds. The strategy does set out the kind of thing government desires. It's good at explaining what is wrong and talks about other important issues - such as water quality, access to the river and footpaths, and the potential for carrying freight and passengers on the Thames.

What about water quality?

That's the one thing we really have got right over the past 150 years. The Thames is as clean as the rivers in other capital cities, if not cleaner, thanks to massive investment dictated by central government. The dead, stinking river of Victorian times has been transformed into one of fair to good water quality supporting more than 100 species of saltwater and freshwater fish. An eight-pound salmon was caught recently in the West India Docks. Unfortunately, the Thames will always be brown and murky due to its strong tidal flows which scour up silt.

And public access?

Under a splendid plan, the Thames Path National Trail, you'd be able to walk beside the river on one bank or the other from the source to the Thames Barrier. But along the 40-mile stretch in London there are numerous small gaps, and some big ones. Worst omissions are two long stretches where one cannot walk on either bank. One of these is at the south- western end of the Isle of Dogs, opposite Deptford. The other is from Wandsworth Park to Battersea Bridge, with the opposing north bank from Hurlingham to World's End also inaccessible. Some landlords and residents refuse to contemplate the public passing between them and their riverside frontages.

As the Thames Strategy points out, getting people to walk beside the river is not only a matter of providing bankside paths. Good pedestrian connections to the rest of London, and clear, coherent signs are needed. New pedestrian bridges and ferry crossings would also encourage walkers.

Why, oh why, don't we make more use of the river to move people? Why has the only proper commuter service of recent years, the RiverBus, gone bust?

We've heard all that stuff about the Thames being a great unused and unobstructed motorway running right through the middle of the capital. But the reality is more complicated. It's a very bendy motorway with a speed limit of about 40mph and a limited number of exits - quays and piers - where you can get off a boat at high and low tide.

The vast majority of London homes are more than a mile from the river, and most West End, City and other central London workplaces are at least half a mile from the banks. This drastically reduces the Thames's potential as a route to work. For all but a few the journey will always be much quicker by train, tube, bus or cycle.

That said, there are about 30 tube and rail stations five minutes' walk or less from the river. The Thames's potential for moving Londoners around their congested, polluted city is desperately unfulfilled. What are needed are large and continuing government subsidies for the riverbus, more quays, more promotion and its integration into the travelcard system. Over to you, Department of Transport.

What about freight? Can't the river be used to get lorries off the road?

It already is. Each year 600,000 tonnes of household and commercial garbage is shipped downstream to the riverside landfill site at Mucking in Essex. Rubbish is the largest single category of riverborne cargo, although another 1.3 million tonnes of minerals, oil, cement, wood, metal scrap and other cargoes make their way up and down the Thames.

The river will only ever be suitable for bulky cargoes moved in hundred- or thousand-tonne quantities; small consignments of goods for shops and business around the capital have to go by road. Its use for bulk cargoes should be expanded, but the trend is in the opposite direction. Road hauliers are always competing to handle the riverborne traffic, and some of the 15 remaining quays where goods are handled are prime locations for yet more riverside office development. Before the last property boom there were twice as many working wharves.

What else is on the riverbanks?

Open space - mainly parks - occupies 28 per cent of the 60 miles (two times 30 miles) of riverbank between Hampton Court and Greenwich. The next biggest frontage is housing with 22 per cent, and this has more than doubled over the past quarter century. Offices, public buildings and shops occupy a slightly lower proportion and have also almost doubled in 25 years. The biggest decrease has been for industry, especially heavy industry and utilities.

Who runs the Thames now?

Many organisations, which makes it difficult to turn dreams and grand visions into reality. As well as the 16 boroughs and the City controlling bankside development, there is the National Rivers Authority which is in charge of preventing flooding and combating pollution. The Port of London Authority is responsible for navigation, dredging and piers while the Department of Transport has to certify all vessels carrying more than 12 passengers.

Have there been earlier visions for the Thames?

Oh yes. Sir Richard Rogers's great linear riverside park, the plans of Victorian engineers to impound the London section of the Thames behind a great barrier, ending the rise and fall of the tides ... the list goes on. Londoners have long had a guilt complex about neglecting their big, muddy river. The first strategic plan for the capital - Abercrombie's 1943 County of London Plan - aimed "to exploit the banks of the river for the benefit of the community to bring this magnificent natural feature into the life of the metropolis".

Finally, excuse the curiosity, but how many bodies are found in the Thames?

On average, one a week, say the Metropolitan Police.