Brighton is unusual among substantial English cities in not being on the banks of a major river.

But unbeknown to many of its inhabitants, there is a river which has had a profound effect on the development of the resort.

The Wellesbourne is a winter- flowing river of a type common where there is chalk. Lewes has a similar stream which can be seen in the Southover area.

Saxon settlers found conditions for living at Brighton ideal apart from the little river which emanated from a spring at Patcham which made low ground boggy.

It flowed through open country roughly where the A23 is today, until it met a second stream coming from Lewes at what is now The Level.

Together they ran down the Old Steine valley to the sea, which they met at Pool Valley, then open to the English Channel.

Because the land was at best swampy and at worst under water, no homes were ever built on The Level or the middle of the Steine.

So we have to thank the little river for the handsome chain of gardens stretching through the centre of Brighton to the sea.

The flow was strong enough at one time to power a water mill at Preston and in the town centre people enjoyed skating on the frozen water in the winter.

When the Royal Pavilion was built, architect John Nash took care to place it on a slight rise above the swamp. But a muddy pool used to form for much of the time just outside the palace on ground where fashionable people liked to promenade.

The Prince of Wales and the Duke of Marlborough together paid the cost of building a wooden sewer to put the river underground and this solved the problem.

Pool Valley was also bricked over, which made it easier to control the river’s flow to the sea after heavy rain.

But problems remained north of the Pavilion and in 1876 both the roads to London and Lewes were made impassable through flooding. More sewers had to be built.

Waterworks at Patcham built in 1889 relieved some of the flooding there but there were still inundations after exceptionally heavy rain.

The most recent and worst example was in the autumn of 2000, when Lewes was also badly flooded.

In Patcham the river rose to the surface and flooded many homes, causing considerable damage. Parts of Preston Village were also affected.

Millions of gallons were pumped away but the flooding was particularly hard to deal with because water was rising from under the houses.

There have been periodic plans to bring parts of the river above ground in the gardens and landscape it.

The most ambitious of these proposals by Lord Cohen of Brighton envisaged taking the concept all the way up London Road to Preston Park but the cost would have been immense.

So the Wellesbourne remains a lost river to nearly everyone apart from those who work in the sewers or go on public tours of them.