The report said the actual water needed was more than double the most recent Australian Bureau of Statistics estimates.
Compiled for DELWP, the report — by consultancy company Aither — found even current levels of plantations are causing a huge issue for the region, which would only be exacerbated in an extremely dry year.
‘‘During periods of future extreme dry water availability, existing permanent horticulture may demand essentially all surface and groundwater available in the connected Murray region,’’ the 39-page report found.
‘‘We estimate that additional development could demand up to an additional 165Gl per annum on top of Aither’s estimates of existing development at full maturity.
‘‘These heightened concerns are primarily driven by constraints that limit the ability to trade water into the lower Murray from above the Barmah Choke and out of the Goulburn and Murrumbidgee.’’
Although admitting their report represents a ‘‘worst-case scenario’’, Aither expects that where the ‘headroom’ between what water is available and what water is required by plantations is reduced, short and long-term increases will follow.
‘‘Additional environmental water recovery from the consumptive pool will further decrease the headroom available above estimated horticultural demand,’’ the report said.
‘‘Aither’s analysis suggests that directly available consumptive surface water supply within the lower Murray may only meet approximately 40 per cent of total existing permanent horticulture demand (at full maturity) under an extreme dry water availability scenario.’’