Police have warned they will take a zero tolerance approach to alcohol-fuelled violence this Australia Day and will be issuing $200 fines to anyone caught drinking outside designated zones.
Commander of the Australia Day police operation and Acting Assistant Commissioner Lawrence Panaia said officers would respond "swiftly" to anyone who was affected by drugs and alcohol and causing trouble.
"The public can expect a significant police presence in areas where large numbers of people are expected to gather," he said. "Our officers will be highly visible and will be moving through the crowds to identify and respond to any issues that arise.
"If you are affected by alcohol and/or drugs, causing trouble and draw attention to yourself, you can expect us to respond swiftly."
There will be two BYO zones for those wanting to drink alcohol at the Skyworks celebrations on Sunday - at Langley Park reserve, bounded by Terrace Road, Plain Street and Victoria Avenue, and at Kings Park on the western side of Fraser Avenue, bound by Wadjuk Way and Administration Road.
People can bring either one six-pack or one bottle of wine per adult between the hours of 6.30pm and 8.45pm.
Anyone drinking outside these zones and times will be fined $200.
Under the Liquor Control Act, police have powers to seize alcohol, even if unopened, from anyone drinking and deemed to be causing or likely to cause undue offence, annoyance, disturbance or inconvenience to others.
The Department for Child Protection has warned revellers to keep an eye on children, with big crowds expected at the Skyworks celebrations.
The department's Skyworks co-ordinator, Jo-Anne Bennett, said staff would be operating lost children posts at Langley Park, Kings Park and the South Perth foreshore.
"Being separated from their parents is very upsetting for young children but we engage with them to keep their spirits high and it is always heart-warming to see children and parents reunited," she said.
Ms Bennett said it was important for parents to talk to their children about sticking together and pointing out people they could go to if they become separated.
She said parents should take note of what their children were wearing and teach their children to memorise information such as the name and phone number of someone they were with.
For younger children, parents are asked to ensure their name and contact details are carried or secured to the child.
Children who become separated should be brought to the lost children's post nearest to where they are found.
Alternatively, children can be delivered to a police officer or security guard, who will accompany them to the nearest post.