The Wellington site in central-western New South Wales allows investigation and monitoring of groundwater resources in fractured rocks at sites that lie at the margin of two important climate belts; the winter dominated rainfall belt to the south and the summer dominated rainfall belt to the north.  Less is known about the water resources available in fractured rocks than practically any other aquifer system, yet fractured rocks cover approximately 20% of the land surface of the world and it has been estimated that approximately 1/3 of all bores drilled in Australia are into fractured rock systems.

Three different fractured rock types have been targeted around Wellington:

Fractured and cavernous limestone at the Wellington Caves and Bell River, approximately 8km south of Wellington. At this site, we have a combination of boreholes, weather station and instrumented caves, uniquely using caves as an observatory of vadose zone processes.

 Fractured granites at the Baldry Hydrological Observatory approximately 50km south-west from Wellington. At this site, surface water, ground water, climate and tree water use are all  instrumented for long term monitoring, in collaboration with the NSW trade industry.

Fractured Ordovician volcanics and metasediments at the UNSW Wellington Research Station. At this site, a dense borefield of over 40 bores, in both alluvial sediments and the adjacent fractured rock aquifer, has been constructed. Abstraction bores in both aquifers facilitate experiments such as aquifer-stress and tracer experiments.

Long term monitoring and investigations at these sites will allow firm predictions of useful groundwater resources in a variety of fractured rock types and also to monitor the response of these systems to climate change. The systems are particularly important for understanding and monitoring dryland salinity and for supporting the increasing demands for groundwater from fractured rock environments as the well developed alluvial valleys become over-committed. The Murray-Darling Basin plan envisages greatly increased abstraction from fracture rock aquifers - yet there has only been limited investigation of reliable groundwater yields. The Wellington Research Station Site straddles the edge of a Tertiary channel so that the connections between the fractured rock and the Tertiary channel fill sediments can be better understood.

The Wellington sites have been widely utilised by national researchers from the University of New South Wales, Macquarie University, the National Centre for Groundwater Research and Training, CSIRO, ANSTO and international researchers from the United Kingdom. The Wellington Field Station and Wellington Caves are also the focus for undergraduate hydrogeology and environmental geophysics field training. The fractured limestone site has been the focus of novel infiltration experiments that will develop novel tracers and test the use of heat as a tracer. The fractured granite site has been utilised by the CSIRO as a test-site for novel soil moisture measurement. The dense borefield at the fractured metasediment site has been used by researchers at Macquarie University to test theories of stygofauna movement, and the abstraction facility used by UNSW researchers to undertake aquifer stress tests to quantify organic carbon fluxes during groundwater abstraction.

Data from the three sites can be uploaded from the Groundwater Data Portal.