Balancing Fisheries Management and Water Uses for Impounded River Systems

<em>Abstract</em>.—The Murray-Darling basin produces about 40% of the total value of Australia’s agricultural output from 1.9 million ha of irrigated agriculture that represents around 75% of the nation’s total irrigation. Major reservoirs in the southeastern states regulate the basin’s river systems for irrigation but also provide recreational fisheries. One of these storages is Lake Eppalock in the state of Victoria, a multi-use impoundment built in 1964 covering 3,230 ha and holding 312,000 ML at full supply level. It has been actively developed as a mixed species recreational fishery (golden perch <em>Macquaria ambigua </em>and Murray cod <em>Maccullochella peeli</em>) and is a popular angling water. The principal recreational target species in the lake compete with invasive pest species (common carp [also known as European carp] <em>Cyprinus carpio</em>). Drought is part of the natural variability of the Australian climate and its rainfall history features several periods of a decade or longer that have been distinctly drought-prone. Eastern Australia was in the eighth year of the latest drought cycle in 2007, and Lake Eppalock had fallen to less than 1% of its full supply level. These conditions highlighted increasing competition for water and brought into focus the interdependence and linkages between fisheries management and water needs, both for irrigation and for the environment. Fisheries managers faced a very strong likelihood of extensive fish deaths in the lake and elsewhere that could cause significant long-term impacts requiring many years to recover the recreational fishery. A planned partnership approach with the storage water authority was adopted in 2006 for integrated fisheries and water management, with response actions targeted to achieve storage conditions ensuring the maximum survivability of key recreational angling species in the lake through the drought. The framework for cooperation established in this study provides an example for future water allocation disputes.