The story of the little boy who put his finger in a dyke is memorable because it speaks of heroism, sacrifice and the David-and-Goliath battle against the elements.

The story of how huge sums of public money were spent building and maintaining the dyke in the first place somehow failed to make it into children’s literature.

Modern engineering know-how may have made it possible for Canute – and the residents of Cuckmere Haven – to hold back the tide, but it comes at a huge financial cost.

The Environment Agency has a budget of £600 million to spend on flood defences this year, a figure that the Government has promised to increase to £800 million by 2010.

Such sums sound big but they are swallowed up quickly, and officials find themselves having to judge which schemes should get priority, which can be put off for a few years and which can be quietly forgotten.

Last year’s extensive flooding was a reminder of just how many parts of the country need tens of millions of pounds spent on them if the whole of Britain is to be waterproofed.

Because it is impossible to find enough money to make everyone safe from flooding, a balance has to be found between the work that needs to be done and the money that is available.

It also needs to be asked whether the money would be better spent, say, on building schools or hospitals.

And so it is, with a few environmental considerations thrown in, that stretches of the coast are being surrendered to the sea.

The retreat comes in different guises, some requiring the active destruction of sea defences by bulldozers to ensure that the sea returns in a controlled manner, and some simply a withdrawal of maintenance so that the battering of the waves and tides gradually destroys Man’s handiwork.

The big winners from the replacement of man-made sea defences with Nature’s “soft defences” are animals and plants, which retrieve a tiny portion of the habitat they lost over the centuries.

From a conservationist’s point of view, the recreation of salt marshes and mudflats is a welcome change from the usual battles in which they try to prevent the destruction of a valuable home for wildlife.

The downside is that several thousand people will lose out. The Environment Agency recognises that it will have to make a number of “unpalatable decisions” as it decrees who should be protected by investment in sea defences and whose homes, lands and businesses should be ceded to the waves.

By and large the decisions are likely to be a numbers game – the number and value of homes, properties and acreage that will be protected from the sea, against the number and value lost and the money saved by deserting them.

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