Territory Stories

Development of a Groundwater Model for the Western Davenport Plains

Details:

Title

Development of a Groundwater Model for the Western Davenport Plains

Creator

Knapton, Anthony; CloudGMS Pty Ltd

Commissioned by

Northern Territory. Department of Environment, Parks and Water Security

Collection

E-Publications; E-Books; PublicationNT; WRD Technical Report 27/2017

Date

2018-03

Location

Western Davenport Water Control District

Abstract

CloudGMS has been commissioned by DENR to develop a numerical groundwater model of the aquifers within the central area of the WDWCD to improve confidence in the sustainability of the groundwater resources, as this is the area within the WCD with greatest potential for intensive development.

Notes

Made available by via Publications (Legal Deposit) Act 2004 (NT); Prepared for Dept Environment and Natural resources

Table of contents

Executive summary -- 1 Background -- 2 Physical -- 3 Available data -- 4 Conceptual model -- 5 Model design & construction -- 6 Parameter estimation -- 7 Water balances -- 8 Sensitivity analysis -- 9 Predictive scenarios -- 10 Conclusions -- 11 Reference -- 12 Document history and version control -- Appendix A - Groundwater level hydrographs - Appendix B - Alek range horticultural farm sub-regional modelling

Language

English

Subject

Groundwater; Northern Territory; Western Davenport Water Control District; Conceptual mode

Publisher name

Northern Territory Governmnet

Place of publication

Palmerston

Edition

version 2.0

Series

WRD Technical Report 27/2017

Format

ix, 127 pages : colour illustration and maps ; 30 cm

File type

application/pdf

ISBN

9781743502976

Use

Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government

License

https://creativecommons.org/licenses/by/4.0/

Related links

https://hdl.handle.net/10070/842058 [LANT E-Publications: Development of a Groundwater Model for the Western Davenport Plains, version 1.1]

Parent handle

https://hdl.handle.net/10070/858845

Citation address

https://hdl.handle.net/10070/858846

Page content

Western Davenport WCD Groundwater Model (v2.0) Available Data CloudGMS 18 The Archean Arunta Complex outcrop to the south and southwest of the study area. The Proterozoic Hatches Creek Group outcrop to the east and south of Murray Downs homestead and north of Alekerange. Rocks of the Hatches Group form the ridges that delineate the study area to the southwest and northeast. These are mostly shallow water sedimentary rocks comprising ridge forming arenites, siltstones, mudstones, shale, carbonates and, possibly, evaporites. The rocks of the Hatches Group are folded into several major, upright, open to tight synclines, anticlines, domes and basins and are displaced by several faults. The Hatches Creek Group has undergone low-grade metamorphism and is unconformably overlain by unmetamorphosed conglomerates and sandstones of Cambrian and Devonian age. These rocks bear different names in the Wiso and Georgina Basins, and an effort has been made in the Stratigraphy of Table 5 to correlate equivalent formations. The northern part of the study area includes the Lander Trough of the Wiso Basin and to the southeast the Dulcie Trough of the Georgina Basin. These two depo-centres are separated from the Proterozoic rocks of Aileron Province by a series of thrust fault systems (Kruse & Munson, 2013). The formations identified within the Wiso Basin include; the Cambrian Hooker Creek Formation, Ordovician Hanson River Beds, and Devonian Lake Surprise Sandstone. The Georgina Basin sediments are the Arrinthrunga Formation, mostly limestone with minor sandstone, and the underlying Chabalowe Formation which consists mostly of sandstone with minor limestone. The Cenozoic deposits consisting of Tertiary and Quaternary aged sediments cover most of the Western Davenport Plains area and generally mask the underlying units. Tertiary sediments unconformably overly the Palaeozoic rocks. They are not seen in outcrop, except for some silty limestone / calcrete near the central Southern portion of the study area, at Bluebush Bore. The Tertiary sediments fill the Lander Trough, with a maximum thickness of 92 m observed in the centre of the study area and wedge out to the north-east over the Hatches Group rocks at the foothills of the Davenport Range. Sediments of Quaternary age blanket most of the area and comprise ferricrete and lateritic gravels, calcrete, silt and gravel, alluvial and colluvial sands, lacustrine deposits and claypans, residual and aeolian sand and silt, including sheet sands and dunes on the plains. Table 3 Summary of stratigraphic succession of the Georgina Basin modified from Kruse, et al., 2013. Age Unit Lithology Depositional Environment Stratigraphic Relationship Devonian Dulcie Formation Cross-bedded, medium to thickly bedded quartz sandstone, with rare beds of silty calcareous sandstone and pebble conglomerate. Continental Aeolian and braided fluviatile Unconformable on Arrinthrunga, Chabalowe Middle to Late Cambrian Arrinthrunga Formation Locally silicified and evaporitic limestone and dolostone, minor quartz sandstone, siltstone and shale. Shallow subtidal to peritidal Conformable on Chabalowe Formation Middle Cambrian Chabalowe Formation Medium to coarse, cross-bedded dolomitic quartz sandstone and dolomitic siliciclastic siltstone, and minor quartzose, silty and peloidintraclast dolostone and mudstone. A basal arkosic conglomerate may occur above Palaeoproterozoic granite Near shore, restricted marine to peritidal