In Südafrika we have this problem a lot. The solution tends to be a simple one; three helicopters with massive buckets hanging beneath work in a relay system, ferrying water from the sea/river/lake to the fire & opening the buckets when above it.
This fire would have been sorted within 2 or 3 hours over there. We have plenty of helicopters here - why am I still seeing pictures of people using fire beaters to try and contain it. Clearly that is not going to work, is it?