Leptospermum species, but given memory is lazy I can say definitely this is the key canopy Leptospermum species that dominates freshwater swamps and riparian habitats ( generally coastal and subcoastal) in much of SE Australia.
In SA the plant is threatened or uncommon over most of its former range mainly due historical vegetation clearance and the 'SE Drainage Scheme' .
It forms tall shrub thickets that are the last refuge for many endangered and rare animals and plants. (On the southern Fleurieu Peninsula in our southern Mount Lofty Ranges region an iconic example is the Southern Mount Lofty Emu-wren,critically endangered)