The father of the 16-year-old Sydney girl who died in a crowd crush at the Big Day Out in 2001 said he is "dumbfounded" by the news that organisers are abandoning use of a secondary safety barrier for three of the six festivals this year.

George Michalik told The Sydney Morning Herald that the most important legacy of his daughter Jessica's death had been the improvements to crowd safety that the organisers put in place after the incident during Limp Bizkit's set at the Sydney Big Day Out eleven years ago.

'Dumbfounded' ... Jessica's father George at her gravesite.

For a decade, the festival has used a "D" barrier to restrict crowd numbers allowed into the area directly in front of the stage. But this year the D barrier won't be used at the Auckland, Adelaide and Perth events.

"In my book was her main legacy. Her whole purpose of living was to make the changes for ever," Mr Michalik said. "I am dumbfounded that these people after only ten years forget why the secondary barrier was there in the first place."