Paddles B'mere said..
I'd imagine there could be money/logistics issues. Those Canadair water bombers wouldn't have the range to quickly fly here
out of curiosity I did a google for maximum ranges
C130 military transport aircraft = ferrying range of 5250km
CL415 amphibian water bomber = ferrying range of 2443km
PBY Catalina amphibian = ferrying range of 4030Km [standard WW2 military specification]
PBY Catalina amphibian = service range of 6652km [as per QANTAS' WW2 flights between Swan river Perth and Colombo SriLanka]
Just goes to show, if you want to get the best out of an aircraft - you can rely on QANTAS!!