Thames Water is to compensate three major arts venues in London after two burst water mains resulted in flooding, causing cancelled performances and putting in jeopardy the opening of a show.

The worst damage was suffered by the Comedy Theatre in Panton Street, Piccadilly, after a four-inch cast iron main spewed hundreds of gallons into the theatre basement, then up through the orchestra pit, submerging the front stalls in five feet of water and soaking expensive electrical equipment.

Its presentation of The Miracle Worker, about the life of Helen Keller, which cost around pounds 200,000 to stage, may have to be shelved, if the theatre, currently without electricity, seats or carpets, cannot be made ready in the next three days.

At the British Film Institute's, Museum of the Moving Image, at the South Bank complex, thousands of visitors were admitted free when the museum waived the pounds 5.50 charge after flooding last week soaked carpets. A 12-inch main had burst under a service road between the Royal Festival Hall and the Hayward Gallery.

Water also forced staff at the Festival Hall to wade through mud, silt and sandbags, the latter brought in to protect the theatre's computer system, which had been temporarily housed on level one of the building.

Bill Kenwright, producer of The Miracle Worker, said he had been forced to cancel two of six scheduled previews and it was doubtful whether the play could go ahead at all.

'We have to open on Tuesday or we are lost. It is crucial to get your own press night to get advanced publicity for the show and for the next 20 nights after Tuesday the press are busy.'

The producer said that, ironically, water featured throughout the play. Annie Sullivan, played by Jenny Seagrove, is the governess to the blind, deaf and mute Helen Keller, played by Catherine Holman.

In one scene, Helen puts her hand on a water pump and suddenly understands. Her first and only utterance in the play is 'water'.

Thames Water said yesterday of the incident at the Comedy Theatre: 'We will indemnify the theatre and production company in terms of liability and in accordance with the Water Industry Act, 1991.'

A spokeswoman said the company would also compensate the Royal Festival Hall and the museum. 'We do accept responsibility and feel sorry for the things that have happened. We are doing all we can to help them financially and practically.'

Thames Water said that the mains, made of cast iron and 'fairly old', had burst due to the hot weather which had caused the ground to move underneath the streets of London.

It said that staff were working round the clock to fit three new valves and pipes in Oxenden Street, which is round the corner from the Comedy Theatre. It said the new pipes were made of ductile iron, which is flexible and moves with the ground.