The Beaufort Street Festival is at a "critical crossroads" and needs more money to secure its future, co-founder and City of Vincent mayor John Carey says.
Mr Carey, a former chairman of the Beaufort Street Network, said Saturday's record 150,000-strong crowd was such that a planned attempt at one of the world's longest Mexican waves had to be cancelled so volunteers could be used to manage the huge crowd. He said without extra funding the festival, a non-profit event, might have to be scaled back.
The one-day event costs $450,000 to put on, about 20 per cent of which was funded by Vincent council and Lotterywest.
"Given it costs $45,000 to $50,000 just to close the road, there's going to need to be a serious commitment of funding to the event to give it security over the next three to four years and to manage that size crowd," Mr Carey said.
He said it was possible the festival might need to run over two days to handle the bigger crowds, which could not happen with current funding.
Given the significance of the festival, Mr Carey believed Tourism WA should "come to the table".
Festival director Paul Fletcher said the festival showed no sign of slowing.
"We are incredibly proud of the festival and what it has been able to achieve over the last five years," Mr Fletcher said. "However, in order to continue to maintain the safety of patrons, and also ensure the spirit and soul of the festival continues, we need to source other funding options above and beyond what we are able to currently secure."
He said for the festival to be sustainable it would need a "significant increase in funding" from Lotterywest or Tourism WA.
Events executive director Gwyn Dolphin said Tourism WA had not received a sponsorship proposal for the festival. "However, we would be happy to see the results of this year's festival and consider a proposal for future events, which would be assessed against our normal funding criteria," he said.
"Both the Beaufort Street Festival and the Beaufort Street precinct in general have experienced transformational growth in recent times and Tourism WA is pleased to have been able to provide promotional assistance to the event this year."