Looks like Grandifolia from here. Could be flood damage of sedimentary sandstone stream banks, within normal range over last 20 years for this high-energy part of the stream which receives stormwater from housing developments almost entirely paved, and from roads.
However many C. grandifolia observed to be suffering from decline/death from unknown cases associated with orange fungi on exudate from wounds (known syndrome) so this could be one. Will check out.
Presumably escapee from nearby property