Lake Eyre Basin Rivers 138 overland flow on the floodplains of irrigation properties into a volume of water extracted. This development occurred despite an embargo in 1992, on the issuing of water harvesting licences. Access to this overland flow, our economic lifeblood and essential for the environment, was at no cost to the irrigation industry apart from their infrastructure and taking the water from the river. The water was free. Initially, there were also no limitations on the volume of water that could be diverted: if the pump was large enough and the water was there, it could be diverted into storage. All this water resource development occurred without a single environmental impact study. The largest irrigation property is Cubbie Station on the Culgoa River, with a licensed storage capacity of 538 800 ML (Sydney Morning Herald 2009), about the same as Sydney Harbour. It has the capacity to take most of a flood. In 2004, Cubbie Station filled its storages to 25% capacity and the flood destined to reach Brenda Station stopped. Our water problems started when Cubbie Weir was built in 1986. It holds back water and moves it into a diversion channel, which is about three times larger than the main channel of the Culgoa River. Our records showed that before 1986, flows of 1000 ML/day for six days (i.e. 6000 ML) reached Brenda Station. In 1989, the height of Cubbie Weir was increased and now flows of 12 000 ML no longer reach the New South Wales and Queensland border, 30 km upstream of Brenda Station homestead. Even our guaranteed supply of stock and domestic flow did not reach us for the second flood in a row in July 2005. Fig. 15.1. Flows from upstream in the Condamine–Balonne catchment flow down the Condamine River at St George where flows are confined to a large channel before the river fans out into a deltaic system with the four rivers of the Lower Balonne. Much of the irrigation development, that has catastrophically altered the Lower Balonne, is near St George and downstream on the Condamine-Balonne, but upstream of much of the Lower Balonne floodplain (photo, R. T. Kingsford).
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