Management pathways for the floodplain wetlands of the southern Murray–Darling Basin: Lessons from history

Abstract

The condition of floodplain wetlands of the Murray–Darling Basin (MDB) reflects the combined effects of climate variability, river regulation, vegetation clearance, and the impacts of human settlement and industry. Today, these systems are degraded, in large part due to changes in the hydroecology of waterways arising from water diversion and abstraction to sustain irrigated agriculture. The MDB Plan directs substantial investment towards the restoration of ecosystems largely via the buy‐back of water allocations, under a cap‐and‐trade system, for use as environmental flows. This region is projected to receive less winter rainfall and run‐off, which could exacerbate the impact of water diversions. Long‐term climate records suggest a higher level of resilience to drying than may be inferred from modern studies. Further, palaeoecological records of change reveal that many wetlands that are perennial today were once naturally seasonal or intermittent, and that much wetland degradation predates regulation and can be attributed to declines in water quality, rather than quantity. A mix of approaches to rehabilitate this long‐degraded system, planned and implemented over an extended period, may meet the demands of the Water Act of 2007, but also support the regional economy. An adaptive management approach offers a framework within which to map system vulnerabilities, characterize climate pressures, identify adaptation options, and monitor outcomes along a pathway to a sustainable future. Early lessons show the extent to which such a deliberative framework can assist water reform under changing socio‐economic priorities and external hydroclimatic pressures.

Relationship between Land Use/Land-Use Change and Human Health in Australia: A Scoping Study

“…In spite of the large impact that agriculture has on water availability and water quality, this remains a large gap in the literature. For example, we found no studies examining the impact of loss of biodiversity, wetlands and rivers on health, in spite of these being major consequences of irrigation [63,64]. We also did not find any studies examining the health impacts of agriculture on microbiological water quality (for example, Cryptosporidium parvum contamination), [65] or any studies investigating the link between agriculture, land degradation and human dust exposure [66][67][68].…”

Wetland management: preparing for climate and coastal change using adaptation pathways

“…In the absence of serious, collaborative attempts to mitigate global carbon emissions the earth is committed to a certain level of sea level rise. Recognising this an approach to implement staged measures to adapt to an ever rising sea on the River Thames and the city of London was proposed [24,25]. It is clear that the immediate implementation of measures and barriers to resist a 1.5 M sea level rise would be premature, given present rates being at ~5 mm/yr, and this would level considerable adaptation cost on the present British tax payers.…”

“…It is clear that the immediate implementation of measures and barriers to resist a 1.5 M sea level rise would be premature, given present rates being at ~5 mm/yr, and this would level considerable adaptation cost on the present British tax payers. Rather than level the cost of adaptation to reduced catchment runoff, compromised water quality and invasive species on the present generation of Murray River water users, such a staged approach could also be implemented which examines the timing of implementation of measures in a staged process thereby spreading the financial impact across generations [25]. Such a planned approach allows decision makers to assess the trade-offs between environmental, economic and social interests and avoids the perverse outcomes of a cap-and-trade market-based approach.…”

Professor Geoffrey Petts (1953–2018): An outstanding interdisciplinary river scientist

“…Gregory et al () illustrate the major hydrological, geomorphological, and ecological changes experienced along the Willamette River, Oregon, USA as a result of human actions over almost two centuries. Gell, Reid, and Wilby () consider even longer‐term changes in the floodplain wetlands of the southern Murray Darling basin, Australia but emphasise more recent consequences of human actions and an adaptive management framework, which may drive a pathway towards more sustainable management in the future. Finally, Seddon et al () illustrate how investigations of palaeoecological and contemporary macroinvertebrate communities can provide evidence to characterise reference lotic conditions and in doing so provide a direct link between themes 7 and 8.…”