Ecological impacts and institutional and economic drivers for water resource development—a case study of the Murrumbidgee River, Australia

Abstract

Much of the world's water for humans comes from rivers for drinking, generating hydro-electricity, industry and irrigation. Dams and diversions reduce downstream flows, particularly to floodplain wetlands, and their fauna and flora. For many countries, including Australia (75% of water use), the greatest user of water is irrigated agriculture. The Murrumbidgee River in the Murray-Darling Basin is one of the most regulated major rivers in Australia. Water resource development, including the building of 26 storages, over more than 140 years on the Murrumbidgee River in southeastern Australia destroyed or degraded at least 76% of the floodplain that once covered 304,000 ha. Remaining wetland areas are also considerably altered. Water resource development in the catchment with subsequent diversion of water and recent development of the floodplain were the main causes of wetland loss. Establishment of two major irrigation areas in Australia, the Snowy Mountains Hydro-electric Scheme and Australia's capital, Canberra were all drivers for upstream development of water. The major local drivers were community values and expectations of water, reflected in Government decisions and legislation. The water and hydro-electricity agencies were primarily responsible for most of the water resource development before the 1970. After 1980, changing expectations on the Lower Murrumbidgee floodplain and Government investment produced rapid development of the floodplain for irrigation. Likely environmental costs were not adequately considered or made explicit for transparent decision-making. Such case studies need to be used when considering likely impacts of future water resource developments on other river systems.