This study is part of the Northern Territory Government Land and Water Suitability Program. It aims to improve the understanding of the area?s hydrogeology, including the extent and properties of the aquifers, the regional groundwater flow pattern, baseflow characteristics, identification of groundwater dependent ecosystems and a basic quantitative assessment of available groundwater. The ultimate purpose of the study is to combine knowledge of water availability with recent land unit mapping to identify areas suitable for various agricultural enterprises.Made available via the Publications (Legal Deposit) Act 2004 (NT).1 Summary -- Introduction -- 2.1 Aim -- 2.2 Background -- 2.3 Location -- 2.4 Topography -- 2.5 Climate -- 2.6 Land Units -- 2.7 Drainage -- 2.8 Previous work -- 2.9 Methods -- 3 Geology -- 3.1 Cahill Formation -- 3.2 Mundogie Sandstone 3.3 Wildman Siltstone -- 3.4 Koolpinyah Dolostone -- 3.5 Mesozoic/Cenozoic strata -- 4 Aquifers -- 4.1 Cahill Formation -- 4.2 Mundogie Sandstone -- 4.3 Wildman Siltstone -- 4.4 Koolpinyah Dolostone -- 4.5 Mesozoic/Cenozoic strata -- 4.6 Connection between aquifers -- 4.7 Flow pattern -- 5 Surface water -- 5.1 Records -- 5.1.1 Baseflow and aquifer type -- 5.2 Twin Sisters Lagoon -- 6 Water Chemistry -- 6.1 Wildman Siltstone -- 6.2 Koolpinyah Dolostone -- 6.3 Mesozoic / Cenozoic -- 6.4 Springs / Spring fed streams -- 6.4.1 Seasonal water quality variation in spring fed streams -- 7 Recharge, lateral flow and discharge 63
7.1 Groundwater level fluctuations and recharge -- 7.1.1 Opium/Jimmys Ck. Catchment -- 7.1.2 Southern / Cashew Farm Region -- 7.1.3 Rainfall and groundwater level -- 7.2 Recharge ? Chloride analysis -- 7.3 Discharge -- 7.3.1 Baseflow -- 7.3.2 Discharge ? Calculated from lateral flow -- 7.3.3 Discharge ? Rainforest Evapotranspiration -- 7.3.4 Seepages -- 8 Water Balance -- 9 Water Availability -- 9.1 Southern palaeovalley aquifer -- 9.2 Dolostone aquifer in the north-west of the study area -- 10 Conclusions -- 11 Acknowledgements -- 12 References -- Appendix 1 Assessment of the rainfall record -- Appendix 2 Geologists Logs and Graphic Logs -- Appendix 3 Pumping test on RN39769 -- Appendix 4 Twin Sisters Lagoon and groundwater interaction -- Appendix 5 Baseflow recession modelling -- Appendix 6 Water quality and flows in Ben Bunga and Cattle Creeks -- Appendix 7 Descriptions of selected springs
