We examined the structure of a consumer food web in a swamp on the Lowbidgee floodplain which was inundated by an environmental flow for nine months. The food web structure was measured as a two-dimensional space (polygon) formed by mean δ13C and δ15N values of consumer species. The change in the food web structure was assessed by examining the shape and area of polygons. We found marked temporal changes in the consumer food web structure with the development of the swamp. The mean δ13C value of the consumer population decreased within the swamp indicating a consumer shift to a more 13C depleted food source. The amount of niche space occupied by the consumer population reduced although the nearest neighbour distance between species increased. We conclude that floodplain habitats such as inundated swamps in the Lowbidgee provide a broader range of food items to consumer species for relatively longer periods of time, enabling the food web structure to develop following an environmental flow.