TY - JOUR
T1 - The rebound effect on water extraction from subsidising irrigation infrastructure in Australia
AU - Wheeler, S A
AU - Carmody, Emma
AU - Grafton, Quentin
AU - Kingsford, R T
AU - Zuo, Alec
PY - 2020
Y1 - 2020
N2 - Over the past decade, Australia has been buying water entitlements and subsidising irrigation infrastructure to reallocate water from consumptive to environmental purposes in the Murray-Darling Basin (MDB). There is considerable evidence that irrigation infrastructure subsidies are not cost-effective, as well as questions as to whether water extractions are increasing (rebounding) as a result. We used 2481 on-farm MDB irrigation surveys and identified a 'rebound effect' on water extractions, with irrigators who received an irrigation infrastructure subsidy significantly increasing (21-28%) their water extraction, relative to those who did not receive any grants. Although the precise hydrological impact of this rebound effect on catchment and Basin-wide extractions remains unknown, publicly available water data suggest that reductions in extractions from the MDB - supposedly commensurate with increases in environmental flows - may have been overestimated, particularly in the Northern MDB. This overestimation may in turn be linked to issues with water measurement and extractions at the catchment and Basin-scale, which occur due to: (1) water theft and poor enforcement; (2) inaccurate or absent water metering; (3) growth in unlicensed surface and groundwater extractions and on-farm storage capacity; (4) legal and practical uncertainties in compliance tools, processes and water accounting; and (5) complexity of floodplain, evaporation and groundwater interactions. To respond to these water governance challenges, MDB water and rural policy actions must: (1) improve measurement of diversions and develop transparent and robust water accounting, independently audited and accounting for uncertainty; (2) improve compliance, fines and regulation; (3) use multiple lines of evidence for water accounting and compliance; and (4) prioritise the cost and environmental effectiveness of water recovery.
AB - Over the past decade, Australia has been buying water entitlements and subsidising irrigation infrastructure to reallocate water from consumptive to environmental purposes in the Murray-Darling Basin (MDB). There is considerable evidence that irrigation infrastructure subsidies are not cost-effective, as well as questions as to whether water extractions are increasing (rebounding) as a result. We used 2481 on-farm MDB irrigation surveys and identified a 'rebound effect' on water extractions, with irrigators who received an irrigation infrastructure subsidy significantly increasing (21-28%) their water extraction, relative to those who did not receive any grants. Although the precise hydrological impact of this rebound effect on catchment and Basin-wide extractions remains unknown, publicly available water data suggest that reductions in extractions from the MDB - supposedly commensurate with increases in environmental flows - may have been overestimated, particularly in the Northern MDB. This overestimation may in turn be linked to issues with water measurement and extractions at the catchment and Basin-scale, which occur due to: (1) water theft and poor enforcement; (2) inaccurate or absent water metering; (3) growth in unlicensed surface and groundwater extractions and on-farm storage capacity; (4) legal and practical uncertainties in compliance tools, processes and water accounting; and (5) complexity of floodplain, evaporation and groundwater interactions. To respond to these water governance challenges, MDB water and rural policy actions must: (1) improve measurement of diversions and develop transparent and robust water accounting, independently audited and accounting for uncertainty; (2) improve compliance, fines and regulation; (3) use multiple lines of evidence for water accounting and compliance; and (4) prioritise the cost and environmental effectiveness of water recovery.
U2 - 10.1016/j.resconrec.2020.104755
DO - 10.1016/j.resconrec.2020.104755
M3 - Article
VL - 159
SP - 1
EP - 17
JO - Resources, Conservation and Recyclcing
JF - Resources, Conservation and Recyclcing
ER -