Water Journal : Current August 2017
www.awa.asn.au 58 GROUNDWATER ABSTRACTION IN THE ROPER REGION OF THE NORTHERN TERRITORY. Striking a balance S MacFarlane, C Fairfield W hen assessing the sustainability of water resources in the Roper Region Tindall Limestone Aquifer (TLA), it is essential to balance the integrity of the environment with maximising the potential of the available water resource. The TLA is one of the NT’s best-quality, highest-yielding groundwater resources. The current NT Government (NTG) is committed to continue its water allocation planning to ensure ongoing management of such resources. Legislation and planning regulations must reflect local use to mitigate wastage and inappropriate use of water. Water resources should be allocated among competing demands to meet socioeconomic and cultural aspirations, minimise pollution, support ecosystems and sustain industry. Water is allocated to end-users based on current and historic information relating to the local availability of water; such data form the basis for water extraction licences. GROWING PAINS In the NT water planning is in its infancy. Water allocation planning (WAP) for the TLA Mataranka began in 2008, with no WAP yet declared. To date, 19 groundwater licences appear on the Groundwater Extraction Licence register for the TLA Mataranka. Water licences give the NTG an independent mechanism with which to reduce water allocations as a result of reduced annual aquifer recharge. executive summary groundwater Historical records of the Roper region TLA are sparse: the most current, modelling report on the Roper River Catchment is the Gulf Water Study. This karstic aquifer undergoes chemical weathering resulting in more permeable, cavernous strata to a depth of 150m. Recent bore drilling in the region has allowed a more accurate assessment of its water resources. Borehole standing water levels (SWL) were used to identify geological Aerial photographs taken of Mataranka. formations and their permeability. With visual on-site inspection and an aerial survey, borehole SWL data can confirm wetland/swamp areas; the prominent vegetation types are typical of paperbark and eucalypt woodland with palms. FUTURE DEVELOPMENT The intensification of agricultural production in northern Australia provides opportunities for economic development. The National Water Commission concluded that only 5% of the 20% available water in the region was allocated (the 80:20 guideline used in the absence of a declared WAP allows for 80% of aquifer water being left to the environment and 20% abstracted; WAP areas account for 160,005km2, or 11.3%, of the NT). As of October 2016, there was an increase in the amount of water allocated in the TLA, although the increase in consumption has been minimal. Recent developments in the Mataranka area highlight the abundance of water available for abstraction from the TLA. Borehole yields reached 130 l s-1, exceeding all prior modelled yield projections in the Mataranka region. Water resources should be allocated Water resources should be allocated among competing demands.
Current May 2017