Likely a pipe dream at this stage. But having just visited south bank in Brisbane it would be awesome to create something similar here.
What I liked about south bank:
-big shady trees to sit under
Lots of nice places to hang out that don't require you to be a customer
open access pool, water playground.
Lots of places to eat
If Perth tried to do it, we would need to bring in the team who did south bank, and keep away the clowns who made the shadeless concrete wind tunnels like yagan square and Elizabeth quay.