looks like a lily perhaps - damp location near point 6 on wetland walk - compare flower size with swamp isotome flower in second photo - in association with brooklime, loosestrife, kidney weed
looks similar to Sisyrinchium rosulatum but yellow petals compare https://keyserver.lucidcentral.org/weeds/data/media/Html/sisyrinchium_iridifolium.htm which has image of yellow form
Based on the most recent descriptions of Sisyrinchium species in the Flora of NSW and Flora of Victoria, it best fits Sisyrinchium rosulatum. It was very useful that you included a scale in one photo; thanks!