Lake Eyre Basin Rivers 146 governments oblivious to the long-term ecological and social consequences on the Marshes. The environmental and economic impacts on Marsh graziers increased in the 1970s and 1980s, before reaching a high level and remaining at this level in the late 1980s, when irrigation development peaked. The annual average flow of the Macquarie was estimated to be 470 000 ML, but the New South Wales government still issued 898 793 ML in licences, including the environmental allocation (Johnson 2005). This meant that, in average years, irrigation licence holders could only be expected to receive ~51% of their allocation. The impact on our livelihoods, and other graziers in the Marshes, was dramatic (Fig. 16.2). The social structure of the community altered considerably in the 1990s, as many landholders no longer had sufficient income to remain viable, given the size of their properties. Some properties were amalgamated and others were run by absentee land owners. This meant fewer people fighting for the marshes and the viability of our livelihoods. Less frequent and less extensive flooding meant that the Marshes got progressively drier (Thomas et al. 2011). They became more difficult to flood as the dry periods got longer, increasing the times between floods (CSIRO 2008). The Macquarie Marshes were often wet and occasionally dry, but now they are often dry and occasionally wet. Their flooding and drying patterns have switched. This has had a huge impact on the plants that grow in the Fig. 16.1. The magnificent Macquarie Marshes in flood, an amazing natural ecosystem extending in all directions and supporting spectacular biodiversity, including waterbirds which breed in large numbers, such as these straw-necked ibises and different vegetation communities (photo, N. Moir).
Downloaded from CSIRO with access from at 18.104.22.168 on Oct 3, 2022, 12:09 PM. (c) CSIRO Publishing