The frantic paddling under the surface that this strategy entails, however, is approaching panic intensity, as water authorities in Andalusia, one of the most badly affected regions, resort to ingenious and expensive measures to keep barren land from becoming a desert.
This is Spain's fourth consecutive year of drought, the worst for 100 years. Since 1992, rainfall in the south has been less than 30 per cent of average; reservoirs are at 10 per cent capacity and falling. At the Concepcion reservoir that serves Marbella, jewel of the Costa and playground for the rich, water laps bleakly at the bottom of a chasm of dry mud. The Rio Verde, which feeds it, is a parched, meandering valley of cracked earth. The reservoir is so low that, for the first time since it was built 20 years ago, houses that were submerged have become visible once more, and people from the nearby village of Istan have been back to have a look at their former homes. "There's only enough water for a bird bath," said one villager as he sat gloomily over an anis in Istan's only bar El Chorro (which translates, cruelly, as "the stream"). "It will be exhausted by June if there is no rain," he added.
The authorities are taking a positive view, in what smacks of a swiftly mounted public relations offensive. The Hydrological Confederation of the South is confident that reserves will last until November. "The Costa continues to be as marvellous as ever, as you can see," the Confederation's spokesman, Manolo Frias, assured me in Malaga. "The water problem is practically solved for us this year."
It is a message repeated by the hotel industry. "They have much worse problems in Israel and the Canary Islands," insisted Francisco Mena, spokesman for the Costa del Sol hotels association. "Desalination plants offer a long-term solution. I'm not worried if it doesn't rain."
But many fear that, should the autumn rains fail again, catastrophe could follow. Restrictions on water usage are in force all over the south, causing inconvenience and hardship to town-dwellers and threatening farmers with ruin. Cadiz, Malaga and Granada are seriously affected and the more northerly provinces of Jaen, Seville, Cordoba, Ciudad Real, Valencia and Castellon are braced for possible restrictions.
A week ago, night-time restrictions were imposed for the first time in Torremolinos, whose 33,000-strong population multiplies five-fold during the summer. In Marbella the water is cut off from 2pm to 6am the following day. Last Wednesday it was cut off for 48 hours without warning when the reservoir dipped so low that air threatened to enter the pipes.
When I ask the mayor of Marbella, the flamboyant Jesus Gil y Gil, how his town hall is confronting the drought, he interrupts me. "Did you turn on your tap this morning?" Yes. "Did water come out?" Yes, but only because hotels have underground reservoirs that can last for up to three days and refill during the unrestricted hours. Householders without tanks fill up the bath and the wash-basins - and, I realise later, the water tastes of salt.
Despite his bravado, Mr Gil takes the crisis sufficiently seriously to have authorised the drilling of 32 new wells, and so furious was he that the confederation - accountable to the Ministry of Public Works in Madrid - had reduced supplies to Marbella and diverted water elsewhere that he threatened reprisals: "We may even consider blowing up the reservoir."
Mr Gil almost spat his disgust at the local and national authorities. "I have no confidence in them because they do nothing." And he added bitterly, referring to the Catalan leader Jordi Pujol, partner in the government of the Prime Minister, Felipe Gonzalez, "If the drought had been in Catalonia, it would have been solved long ago." For him the long-term solution lies in piping water from the north.
Spain's struggle for water is political. The government's National Hydrographic Plan has been meandering through parliament for more than three years, dammed into sluggish backwaters by the refusal of the country's water- rich regions to allow transfer of their precious resource. The plan, which would involve the construction of pipelines to channel water from north to south, was conceived to cope with what is recognised as long- term climate change.
Cuts in the water supply which now affect 2 million people may affect up to 8.5 million if there is no rain this autumn, the government estimates. In February, the government announced that it would spend 1.2bn pesetas (£6.3m) on emergency measures, but still hoped that the spring rains would save the day. The spring rains never came, and some emergency measures are now in train.
The most spectacular so far was a plan to ship water from the Ebro river in a tanker from the Catalan port of Tarragona to the Mallorcan capital, Palma. On 10 April the floating reservoir Mostoles arrived with 30 million litres of water to supply the thirsty island. The maiden voyage was a fiasco: the ship's recently repainted hold had not dried properly and the water was tainted with solvent, and so undrinkable. In the port of the parched island, the ship's entire cargo was tipped into the sea. The mercy shipment is due to be repeated every three days.
The government has instructed the ports of Cadiz, Huelva and Malaga to prepare for the possible accommodation of reservoir ships, but in Marbella Mr Gil is sceptical that this offers anything more than emergency cover. "Sticking plaster" was his verdict.
Earlier this month, southern farmers tramped for days across their arid lands to the Andalusian capital, Seville, where they held up their stunted vegetables to the cameras and beseeched the authorities to give them money to improve ancient infrastructure - 40 per cent of water is lost through leaky pipes - to transfer water from the north, and to compensate farmers for ruined crops. "What the government offered us is a siren's song - it sounds beautiful but it means nothing," said Javier Madrid, a leader of Uaga - the farmers' union of Andalusia - in Seville last week.
Farmers are having to abandon crops that require regular watering, such as rice and cotton. Last week the Andalusian government warned in its weekly farmers' bulletin that producers of sunflowers and chickpeas needed rain urgently if their plants were to survive. The drought is even threatening Spain's traditional citrus cultivation. Agriculture is the thirstiest sector in Spain, gulping down 80 per cent of the country's water. The rest is divided equally between industry and what the statisticians call "human use".
Human use is where most of the Costa's water goes. But in the resort town of Fuengirola, which has water only on alternate days, "we are not drinking the water any more, it tastes so bad," says Ken Brown, a Briton who has lived on the Costa for 32 years. Ken, who works in Fuengirola but lives in nearby Mijas, fills big plastic bottles from a public fountain of spring water in Mijas for his colleagues to share, but now water from the Mijas fountain could be rationed.
In the bars of Fuengirola they make coffee with mineral water, and Dianne Fletcher, who has lived in the town for three years, does all her cooking in mineral water. "The water's always off at night all along the coast. You end up buying five-litre bottles of water just for washing, and you get used to taking buckets from the swimming-pool to flush down the loo."
A town hall spokesman, admitting that some of the city's water tasted foul, said there was a problem with one of the recently drilled wells whose water contained a high concentration of salts, but he insisted there was no health risk.
Throughout the parched province of Malaga, a political row is raging over the prospect that Peter will be robbed to pay Paul. Juan Ferrer is president of a farmers' association in the Axarquia agricultural region east of the city of Malaga which produces mangoes and avocados, and early vegetables under plastic. The area is supplied by the Viniela reservoir that the Minister of Public Works, Jose Borrell, on a recent visit, promised would soon be linked by a new pipeline to the city of Malaga. The prospect fills Mr Ferrer with horror. "We are quite opposed to taking water from our reservoir to serve Malaga and the Costa while Malaga does not exploit the resources it has to the west. The area of the Sierra de las Nieves has lots of water."
The pine forests of Sierra de las Nieves in the west of the province have recently been granted special environmental status by Unesco. The village of Istan is on the edge of the forest and a notice pinned up in the El Chorro bar announces that the mayor, Ines Ayllon, refuses to allow wells to be drilled until environmental studies have been made into the effects.
This cuts little ice with Mr Ferrer. "I respect the environment, but communities shouldn't have to die for the sake of half a dozen pine trees. If they take water from our reservoir to supply the tourists along the Costa, we'll be the ones to pay the price."
This is the fear throughout the south - that residents will be made to suffer to keep the tourists happy. It was summed up in acid fashion by a commentator in Cambio 16 magazine this week: "The day will come when we Spaniards will swim in shit for lack of water, while the tourists enjoy what little there is; and we will have to disguise ourselves as tourists to get a shower, and teach golf in schools so that our children can walk on real grass."