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) Background CloudGMS 1 1 Background 1.1. Introduction The Western Davenport Water Control District (WDWCD) is located approximately 150 km south of Tennant Creek and extends over an area of approximately 24500 km2. The southern boundary of the WDWCD follows the outline of the Ti Tree WCD and extends up from about 10 km north of Wilora in its centre to include the community of Mungkarta at its northern edge. From the west it includes the Hanson River and extends east to cover most of Murray Downs Station. The Stuart Highway bisects the Western Davenport WCD passing through Barrow Creek, Wycliffe Well and Wauchope. Groundwater accounts for 100% of water supplies in the WDWCD so that, essentially, all public water supplies, and the pastoral and horticulture industries rely on it. The aquifers currently provide domestic water supplies to Alekarenge, several Aboriginal outstations, two homesteads, one roadhouse and associated tourist facilities. Stock water for three cattle stations is extracted using stock bores across the WCD. The annual extraction from the aquifers is estimated to be less than 2000 ML/a. Regional aquifer assessment incorporating diffuse recharge processes, storage and unsaturated zone losses are best simulated using a numerical 3-D model with the capability for transient state modelling. Analytical models can be used to assess local development scenarios i.e. determining borefield performance / well interference, however, analytical models are considered unsuitable for groundwater basin sustainable yield estimation mainly because they lack the ability to simulate output mass balance but also because their treatment of inflow and outflow component interaction cannot be rigorous and their response is based on linear superposition theory. These models are considered more appropriate to local and first- pass assessments. Sustainable yield calculation based on the groundwater level response alone using such models is not considered suitable (Kalf & Woolley, 2005). 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. 1.2. Modelling objectives The objectives of this numerical groundwater modelling study of the central Western Davenport aquifer system: determine water balance estimates for the various aquifers in the central WDWCD. inform future appropriate volumetric extraction rates (e.g. how best to limit the groundwater level drawdown for existing users and GDES by modifying the pumping regime); and confirm the sustainable yield of the aquifers within the central zone of the WDWCD, which in turn will enable DENR to formulate a Water Allocation Plan based upon a range of predictive scenarios as well as the response of the aquifer to medium and long term extraction stresses. 1.3. Modelling study scope of works The major components of the groundwater modelling study will include: Data review and conceptualisation; Model design and configuration; Steady state and transient model development and calibration;