DOI Water issued a groundwater allocation updated on Wednesday the 22nd of May 2019 in regards to possible reductions on 2019/2020 season groundwater allocations. Click here to read the whole statement
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NSW Groundwater
Water allocation update
The extreme dry conditions across most of inland NSW appear set to continue. Surface
water resources are dwindling and there is an increased dependence on groundwater
sources. Resource management focus is on ensuring average annual pumping volumes are
kept within the limits set in the water sharing plans.
The NSW mapping of rainfall deficiency (above) shows that rainfall for the last two years
across most of NSW has been in the lowest 10 per cent of years on record, with some areas
amongst the lowest ever recorded. As a result of the lack of surface water flows there has
been sustained high volumes of groundwater extracted over the last few years, particularly in
the north of the state. The dry conditions have also resulted in limited recharge of
groundwater systems.
Water sharing plans allow groundwater to be temporarily pumped for some years at higher
volumes than the annual limit. This provides some operational flexibility around seasonal
variation in conditions, for example droughts. However, the plans also set limits on the
period that this higher level of extraction can continue. Once the compliance trigger is
reached groundwater allocations are required to be reduced until the extraction is back
within limits. This helps to prevent resource depletion.
Water allocation outlook
The 1 July water allocations are currently being calculated. For two water sources the plan’s
compliance trigger has already been reached and will require a reduction in allocations.
Reduced allocations for Aquifer Access entitlements may also be expected in some other
groundwater sources (Table1).
WaterNSW is prioritising the processing of meter data for groundwater systems that have
extraction levels approaching their plan’s compliance trigger.
Reduction in allocations action is required under water sharing plan rules when the average
annual extraction exceeds the plan’s compliance trigger. Reduced allocations are intended
to return extraction to within long term sustainable limits.
Groundwater entitlements in alluvial systems where allocation depends on the surface water
allocation can expect a reduced allocation on 1 July, if the surface water allocation is
reduced.
Table 1 Groundwater sources that could expect reduced allocations on 1 July 2019.
Not all groundwater meter readings can be finalised prior to the 1 July 2019 announcement,
therefore some projections of annual water usage to 30 June will be necessary.
Projections will be checked using actual data as it comes to hand and where a reduction has
been imposed, but an increase in the allocation is possible while remaining compliant with
the water sharing plan, a further allocation will be made in early October 2019.
All other water groundwater sources can expect their usual allocation for entitlements on 1
July for the water year 2019-20.
The calculations are based on the volumes pumped in the current and previous years to
determine the average annual extraction over the compliance period. The plans set a
compliance period of either five or three years. They also have varying exceedance levels,
typically 5 per cent or 10 per cent above the extraction limit.
Those groundwater sources that have higher exceedance levels and/or longer periods over
which the average extraction is calculated, could require longer periods of reduced allocation
to return to the water source to sustainable levels of extraction.
Further information
Information on available water determinations and water sharing plans is available on the
Department of Industry website – www.industry.nsw.gov.au/water
