The Murray–Darling Basin: Climate Change, Infrastructure, and Water

The extreme climatic variability historically experienced in Australia’s Murray-Darling Basin and the institutions developed to respond to it have generated key lessons for managing water infrastructure under climate variability and change. In response to highly variable river flows, surface water storage systems have been constructed in the Murray-Darling Basin that can store nearly three times the average river discharge, and groundwater is increasingly exploited. These interventions have negatively impacted the environmental health of the river system. Severe droughts have exacerbated the environmental impacts, threatened livelihoods, and exposed weaknesses in management. Incremental reforms have been introduced to better manage climatic variability. A number of key water management reforms for climatic variability are described in this chapter, including capping consumptive water extractions; conjunctive management of surface water and groundwater; establishing a water market; rebuilding water storage, distribution, and irrigation infrastructure to reduce water losses; and reallocating water to environmental flows. These have dramatically changed the way that surface water infrastructure is operated. Reforms in 2008 led to the adoption of a new basin plan for implementation from 2019, but there is little allowance for climate change despite projections for changing water availability in the future. The lack of periodic relicensing is a missed opportunity to systematically reoperate water infrastructure. Surface water and groundwater resources are further threatened by other changes, including the exploitation of unconventional gas and carbon sequestration plantations.