The Coronation Fountain, a landmark in Welwyn Garden City, had to be turned off due to the hosepipe ban.
However, the council is now paying Â£450 to fill it up again, so that the town looks its best for key 2012 events.
It will be working on the 4 and 5 June and when the Olympic torch relay passes through the borough on 8 July.
The fountain on Parkway in the town was built to celebrate the Queen's accession to the throne in 1952.
It is supplied by an underground tank, but had to be switched off after the water level dropped and could not be refilled.
The council is buying water from a landscaping firm which already supplies water from a natural lake source, to maintain the borough's open spaces.
It cannot be drunk so is permitted under the hosepipe ban regulations.
Council chief executive, Michel Saminaden, said: "They have told us that there is an abundance of water in this lake so we are probably doing them a favour by taking it."
Mr Saminaden added that the council decided against asking the Veolia water company for a special dispensation.
"I thought that wasn't the right thing to do because we would be using precious water," he said.
"What we are doing now is using water that is surplus and we have been told categorically that there is no problem in using it.  This is a better all round sustainable solution.
"I am extremely pleased that we have been able to find a solution which will enable everybody to see the fountain in all its glory on the occasion of these two great celebrations."

A young palaeontologist working with the University of Manchester found the fossil in 2008, in the collections of Doncaster Museum and Art Gallery.
He realised it was the 189-million-year-old remains of an ichthyosaur - an extinct marine reptile.
Further study confirmed it to be a previously unknown species.
The finding has now been published in the Journal of Vertebrate Paleontology.
Dean Lomax, the 25-year-old palaeontologist who studied the specimen, said it was so well preserved he could determine the contents of its stomach.
"We could see tiny hook-shaped features that were actually the hooks from the tentacles of squid," he said.
"So we know what its last meal was."
Mr Lomax worked with Prof Judy Massare, from the State University of New York, comparing the specimen's fossilised bones with those of almost 1,000 other ichthyosaurs in museums in the US and Europe.
Mr Lomax explained that subtle anatomical features in its fin bones set the species apart from others.
It is not uncommon to find ichthyosaur fossils in England. The sharp-toothed marine reptiles swam in large numbers in the seas around Britain when the dinosaurs roamed.
This particular specimen was found in the rocks of Dorset's Jurassic Coast in the early 1980s and brought to the museum, so it is not clear how it was eventually mistaken for a copy.
Dr Silvia Danise from Plymouth University said its "rediscovery" was a "striking example of how important museum collections are for scientific research".
"Collections are treasures that show their value each time we're able to look at them with a different perspective, and by asking new scientific questions," she told BBC News.
Dr Blanca Huertas, from the Natural History Museum in London, pointed out that there were still many species to discover in museum collections.
"Sometimes we discover things in the field," she said, "but the collections are an incredible source of opportunities, since visiting them, people can study specimens and collections from hundreds of places across the entire planet and travel in time."
Source: Encyclopaedia of Paleontology.
This new species has now been named Ichthyosaurus anningae - in honour of Mary Anning, the British fossil-hunter who discovered the first ichthyosaur on the Dorset coast in about 1811.
The hope now is that news about the significance of this ancient specimen might help track down the fossil hunter who found it.
Dr Stephen Brusatte, a palaeontologist from the University of Edinburgh added that there was "a whole lot more still to find out there".
He told BBC News: "Palaeontology is a unique science because you don't need an advanced degree or specialised training to find a fossil, just patience and a keen set of eyes."
A Hertfordshire council is buying in water from a local landscaping company so that a town fountain can be switched on for Jubilee celebrations.
[NEXT_CONCEPT]
A fossil stored in a Doncaster museum for 30 years and thought to be a plaster copy has turned out to be a new species of ancient reptile.