'Monstrosity on stilts': Powerhouse museum under fire after Parramatta River floods

With sections of the construction site for Sydney’s Parramatta Powerhouse now submerged by flood water, debate has reignited over the suitability of the $915m project’s riverside location.

An independent Parramatta-based flood management consultant, Steven Molino, told Guardian Australia on Monday that events over the past three days should serve as a wake-up call to the New South Wales government.

“The lower parts of the Parramatta Powerhouse will go underwater … that’s just the nature of the riverside location that has been chosen,” he said. “Now it’s up to the state government to decide whether the risk is worth it – and that risk assessment has not been done.”

The Parramatta River broke its banks on Saturday, flooding the path that runs alongside the museum site and inundating the ground floor of a four-level car park slated for demolition as part of the museum’s construction.

It is the second time in just over a year that the proposed site for the museum has been inundated by a swollen Parramatta River during heavy rainfall.

On Monday the NSW premier, Gladys Berejiklian, rejected suggestions that flooding in the Parramatta precinct proved the location’s unsuitability for the state’s most ambitious museum project to date.

“I dispute that strenuously,” she said, before handing over to the local Parramatta state MP, Geoff Lee, who said he had conducted an inspection of the affected area on Sunday.

“[What] we have had is a bit of water there, but we have a 68-storey building right next to the Powerhouse [site], it is five metres up … it is not flooded,” he said, adding that any claims to the contrary were “spurious” and “absolutely misleading”.

A statement issued by the Museum of Applied Arts and Sciences said the museum’s design and engineering considerations would ensure that in a one-in-1,000 year flood event water would not even reach the building’s ground floor.

“What the weekend demonstrates is that our new museum, Western Sydney’s first cultural institution, is positioned well above even the rarest of flood events,” said the museum trust’s president, former NSW Liberals leader Peter Collins.

“The flooding we saw on the weekend wouldn’t have come within four metres of the museum entrance.”

The NSW’s opposition spokesperson for the arts, Walt Secord, said the government must heed the weekend’s warning and move the site to drier ground nearby, at the Female Factory site.

“This was supposed to be a one-in-1,000 year event, but it has happened twice in two years,” Secord said. “In a desperate bid to overcome the flooding problems, the Berejiklian Government has created a monstrosity on stilts.

“The Powerhouse Parramatta site has now been inundated by flooding twice in less than two years, yet [the government] is continuing with this debacle of a project despite expert after expert advising against this site.”

Molino, who gave evidence at the state government’s inquiry into museums last month, said the government’s much-vaunted one-in-1,000 year scenario meant that in the building’s predicted 100-year lifespan, there was a 10% chance that water was going to get into the building.

“If it was an office building with just office furniture and carpets and everything, it wouldn’t matter – if it gets flooded you go down to Carpet Court and buy new carpet, you go down to Officeworks and buy new furniture – it’s all easily replaced,” he said.

“But the information we have at present suggests that the electrical power supply will go out [during flooding] and the generators won’t operate the air conditioning system. So you’ll have a spike in humidity … and if you’ve got items in the collection made from paper, textiles, and even wood and some metals, [the museum’s] collection will deteriorate, be possibly irreparably damaged or even lost.

“Now the decision might be made that the probability of this occurring is an acceptable risk, but no one has gone through that process.”

The Infrastructure NSW-delivered project must go through such a risk assessment, but only after construction has been completed and the project reaches its occupation stage.

A museum specialist and member of the Powerhouse Museum Alliance, Kylie Winkworth, said Molino’s concerns were valid.

“It is odd that the condition of consent to investigate the risk of flood damages to the collection is conditioned at the occupation stage instead of prior to construction, when it should in fact have been part of the EIS [environmental impact statement],” she said.

“The NSW Government will spend $1bn and not know if the building is fit for purpose and safe for collections until it is ready for occupation.

“This is quite bizarre – and reckless.”