More water could soon be available from the Cromwell aquifer.
The 22.2sq km aquifer under Cromwell township and bordered on two sides by Lake Dunstan is technically over-allocated.
There are 22 consents to take water from the aquifer which irrigates about 100ha of the Cromwell terrace, most of which is developed as orchards and vineyards.
Other activities reliant on water takes from the aquifer include bottled water for export, frost fighting and supply to a community water scheme.
There are also 40 bores supplying domestic water and stock water to properties on the terrace.
A report by Otago Regional Council scientists showed in reality only about 400,000cu m was actually being taken through bores each year compared with the 1.7 million cu m per year allocated by consents.
The interim default allocation limit for takes from the aquifer was set at 50% of its mean annual recharge, which was 1.2 million cu m per year.
The council proposed to set a maximum allocation volume of four million cu m per year.
Policy analyst Tom De Pelsemaeker said in a report to the recent policy committee the council had gauged the community's aspirations for managing the aquifer and the proposed allocation limits at a workshop earlier this year.
''Feedback ... indicates that there is broad support for allowing more groundwater to be allocated from the aquifer, as long as there is no adverse impact on existing uses or known values.''
Maximum allocations limit the volume of water that can be taken annually from an aquifer by consents and was set to maintain long-term groundwater levels and avoid damage to the aquifer.
Under the old regime the aquifer was considered over-allocated and consents for new groundwater takes from the aquifer could not be granted.
Last year's study concluded the aquifer was receiving a modest volume of infiltration from irrigation, rainfall and inflow from the Kawarau arm of Lake Dunstan and discharging most of the excess back into the lake.
Groundwater modelling showed the aquifer was in ''dynamic equilibrium'' with Lake Dunstan and compensated for increased groundwater extraction with the increased infiltration of lake water.
Further investigation showed the risk of water table decline and permanent aquifer damage was negligible.
''Despite the existence of large number of bores located across the aquifer, there are no known issues with generalised or localised water table decline.''
A consultation report said if the allocation limit was increased the community would in a better position to pursue economic opportunities as the further allocation of locally available groundwater enabled more productive land-uses to occur and minimised the cost of water transport infrastructure.
''Likely spin-off effects for the local and wider community include job creation in the local primary sector and ancillary industries.''
The council is now consulting those who took part in the aquifer workshops, the appropriate Government ministers, Central Otago District Council, iwi and groundwater consent holders in the area.
It plans to amend and publicly notify proposed plan change 4C (Groundwater management: Cromwell Terrace Aquifer) next month.
