The flooding of AFC Wimbledon's football ground was "totally predictable" given the history of the site, a campaign group has said.
Heavy rain caused drains to back up, with the Cherry Red Records Stadium swamped by 10,000 litres of water - leaving the pitch unplayable.
The flood on September 22 triggered a fundraiser to repair the pitch and get the club hosting matches again.
Michael Burnage, of the Save Wimbledon Stadium Action Group, had campaigned to save the previous stadium on the site which hosted speedway and dog racing but was demolished in 2002.
He claimed that everyone at AFC Wimbledon was aware that the site was a flood risk and it had been hit many times in the past, including a devastating deluge in 1968. The stadium is also close to the River Wandle which has burst its banks in the past.
Mr Burnage told the BBC: "We all knew that it was just a matter of time. The question in our mind was not if there would be a flood on the site, but when it would happen."
A League Cup tie with Newcastle United was one of the games postponed after the pitch collapsed following the latest flood. Drone footage showed the extent of the damage to the pitch and stadium which was opened in 2020.
The first match back at the ground since the flooding will be against Carlisle United on Saturday. Newcastle United donated £50,000 to AFC Wimbledon to help it fix its pitch.
A crowdfunder raised more than £100,000.
Mr Burnage added: "We have every sympathy for the staff and officials of AFC Wimbledon having to deal with the impact of this latest flood, but to say it was unpredictable is simply not true.
"As part of our campaign, we highlighted our years of experience on the site, recalling the countless times that the stadium and the car park were flooded."
He said that developers, the council, City Hall and the Environment Agency were all warned about the dangers of future flooding, adding: "We are incredibly frustrated by recent events."
Jon Stevens, a curator of the Dons Den, which is home to many items from the previous stadium's speedway heyday, said "historically, it's always flooded".
He told BBC London: "It's been well documented that it's flooded quite substantially.
"Regarding building a brand-new stadium and it still flooding, I guess maybe something’s been overlooked.
"I don’t know why they did that: that’s the million dollar question.
"Were there enough measures in place to combat any potential flood?"
An Environment Agency spokesperson said: "As the stadium is a brownfield redevelopment in a high-risk flood zone, its planning involved lengthy discussions, mapping and reports on how the flood risk would be managed.
"We originally objected to the proposed development due to insufficient information. Once this had been supplied, we were able to remove our objection and requested several planning conditions."
A Merton Council spokesperson told the BBC: "The stadium is built on previously developed land with a historic risk of flooding, a risk common across many developed areas of London.
“Given this risk, and the increase in flash flooding caused by our changing climate, the planning proposal was, like all proposals, examined rigorously.
"The council’s planning committee and the Environment Agency sought to ensure the stadium would remain safe, that the building would not increase risk of flooding nearby, including to homes, and that damage mitigation and recovery plans were thorough and robust.
“We are working closely with the Environment Agency and AFC Wimbledon to manage the risk of flooding, and to support in the review of the club's flooding processes.”
The club said it had been “overwhelmed by the generous financial contributions” following the flood. “‘From everyone at the club, thank you to each and every person and organisation who has done so. We are eternally grateful.”
