London — Britain, which probably sports more brollies (umbrellas) per capita than any other nation in the world, is experiencing the improbable: a severe drought. In Wales and the western half of England the drought is the worst in living memory. Reservoirs are drying up. Rivers are receding. Evaporating marshlands threaten Britain's rich bird life, and normally lush green meadows are unrecognizably brown.
The grassy banks that sweep down from Princes Street to the rocky foundations of Edinburgh Castle in Scotland's imposing capital city look more California brown than Scottish green.
For a country that can be as wet as a sponge, the protracted dry spell has meant water restrictions, including a ban on using garden hoses, for more than 20 million people, or 40 percent of the population.
Although the heaviest rains in months have doused England's southwest in recent days, it will need to rain ''incessantly and torrentially for weeks and weeks to restore the situation to normal,'' says Martin Smith, a Glaswegian in the Department of Environment. ''You can't make up in a few days what we haven't had for months,'' he explained.
A colorful pamphlet entitled ''Your Water,'' which people can pick up in the waiting room of the Thames Water Authority in London tells the way it should be:
''Everyone in Britain is aware that water is plentiful. Hardly a week goes by without rain, and if the weather's dry for a fortnight we call it a drought!''
Clearly that pamphlet went to press before the unusually warm Easter, which seems to have marked the beginning of the drought that is singeing so much of what William Blake once described as England's ''green and pleasant land.''
So unexpected is the drought, even though Britain experienced a severe dry spell eight years ago, that people are tempted to say, ''It must end soon. It's not natural.''
The long, dry, sunny days are a boon at least to the nation's cereal farmers, who are rubbing their hands over the prospects of a golden harvest, and to the record 13 million tourists taking advantage of the good weather to tramp all over the British countryside this year.
The British weather, notoriously fickle at the best of times and a prime topic of conversation for Britain because of it, has been particularly perverse this year.
This is because the west (Devon, Cornwall, the Lake District, Wales, and the Western Isles of Scotland), normally the wettest parts of Britain, are the worst-affected drought areas. Scotland's Western Isles can get between 120 and 150 inches of rain a year. The east (London, East Anglia, and the channel ports, usually the driest part of Britain) has largely escaped this year's drought and is maintaining adequate water supplies.
The River Thames, for instance, is down to only about 89 percent capacity, but Portsmouth, Devon's largest city, which normally receives 12 inches of rain between March and July, has so far received only half its usual quota of rain.
Derek Gregg, assistant manager of the Thames Water Authority, the largest of the Thames regional water authorities in England and Wales, explains this year's idiosyncratic weather patterns: ''During the winter we had for very long periods the winds in the north or north by east, which meant that it was the eastern seaboard of the British Isles which got the sort of rainfall expected in winter. Ironically we found ourselves, although historically the driest part of Britain, with ample supplies.''
''Normally,'' he explained, ''this country gets southwest winds, which bring the soft, refreshing rains to Devon, Cornwall, Wales, and the northwest, which are very seriously depleted.''
The public-spirited attitude of Britons to cut down on their water usage has pleased water authorities, who say this has helped conserve dwindling stocks. In numerous cases where restrictions have not yet been requested, citizens have called up to find out if it is all right to use their hoses in a country where gardening is a passion.
But the occurrence of yet another drought, so soon after the equally unusual 1976 drought, has brought taunts from some quarters that the country has failed to learn the lesson of 1976.
Since the 1976 drought about half a dozen new reservoirs have been built. In the case of the proposed Roadford reservoir in Devon it has only recently received the go-ahead.
According to a source who has watched the incessant maneuvering since 1976, there were too many interested and conflicting parties. Farmers didn't like to see such good pastureland going for a reservoir. Environmentalists were concerned about saving the hedgehogs. Scientists, realizing that the west was more prone to earthquakes, were troubled by the seismic effects an underground disturbance might have on the reservoir walls. And the local water authority was at odds with the government on the scale and the kind of demands that would be made on the reservoir.
Today, eight years after it was originally proposed, they are only now starting to break ground.
The problem with comparisons with 1976, the experts say, is that the situation is not comparable. Any improvements since 1976 would only be meaningful if the east, which was worse hit in 1976, were similarly affected this year. But it is not.
In part, the west did not proceed far with drought precautions in 1976 because it was not affected by that drought and because it has an ''it-always-rains-in-the-west'' mentality. Or so they thought. The vagaries of this year's weather pattern suggest that residents in the west may have to revise their assumptions.