Territory Stories

North Bathurst Island Groundwater Assessment

Details:

Title

North Bathurst Island Groundwater Assessment

Creator

Woltmann, Melissa

Issued by

Northern Territory. Department of Land Resource Management

Collection

E-Publications; PublicationNT; E-Books; Report 15/2015

Date

2015-06-01

Location

North Bathurst Island

Abstract

A hydrogeological investigation was undertaken in 2014 as part of a broad assessment of the natural resources in the North Bathurst Island area. This information is intended to provide a basis for the assessment of the suitability of the area for horticulture or other developments. The focus of the groundwater study was to characterise and elucidate the shallow unconfined aquifer hosted in the Van Diemen Sandstone, with some scope to investigate the deeper confined aquifer within the Moonkinu Sandstone. This report details the findings of the study.

Notes

This report has two volumes - Volume 1 Main report and Volume 2 - Appendices; Made available via the Publications (Legal Deposit) Act 2004 (NT).

Table of contents

Executive summary -- Introduction -- Hydrogeology -- Geology -- Aquifer Occurrence and Extent -- Aquifer Parameters -- Groundwater Movement and Recharge -- Water Quality -- Bore Yield Potential -- Conclusions -- Recommendations -- References

Language

English

Subject

Hydrogeological investigation; Van Diemen Sandstone Aquifer; Moonkinu Sandstone

Publisher name

Northern Territory Government

Place of publication

Darwin

Series

Report 15/2015

Format

2 volumes : colour illustrations and maps

File type

application/pdf

ISBN

9781743500828

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/10070/457837 [North Bathurst Groundwater Assessment - Volume 1 - Main Report.pdf]; https://hdl.handle.net/10070/457838 [North Bathurst Groundwater Assessment - Volume 2 - Appendices.pdf]

Parent handle

https://hdl.handle.net/10070/265580

Citation address

https://hdl.handle.net/10070/457837

Related items

https://hdl.handle.net/10070/457838

Page content

21 At Site 2, two observation bores, RN38704 and RN38715 were constructed at different levels in the aquifer to gain a measure of homogeneity in the aquifer. RN38704 was screened in the lower part of the aquifer and RN38715 was screened closer to the top. They were analysed together and separately. In both cases, tidal influences precluded the analysis of late response data providing indication of the aquifers drainage characteristics. However, the separate analyses in Figure 2-11 produced hydraulic conductivity and specific yield values that were consistent indicating a degree of homogeneity in the aquifer. These values are in reasonable concurrence with the parameter values determined by Yin Foo (1992). The results from the combined analysis in Figure 2-10 which converge at a significantly different bulk specific yield value may be an indication of anisotropies in the aquifer. The analysis of Site 3 data produced a hydraulic conductivity value slightly higher in magnitude with a very low specific yield value. The early time data is not considered a good match to the theoretical curve. This bore had sanding issues and was the primary source of drilling and camp water supply. The observation bore response displays near well storage effects probably due to erosion of the aquifer adjacent to the bore. A summary of the aquifer parameters determined from constant rate analysis are presented in Table 2-3. Plots of log time versus drawdown for both constant rate and stepped rate tests are presented in Appendix C. Note that the plots of the logged observation data show both barometric and tidal effects. Table 2-3 Unconfined aquifer parameters Van Diemen Sandstone Site Observation Bore K (m/day) Saturated Thickness (m) T (m2/day) Sy Radius (m) 1 RN38708 11.5 est.45.5 525 0.034 19.3 2 RN38704 4.3 52.3 271.4 0.1 27.4 RN38715 5 52.3 254.7 0.05 36.3 3 RN38717 9 32 289 .0017 30.25 Yin Foo (1992) reports a transmissivity range of 60 300 m2/day for Nguiu. Yin Foo also identified that observation bores at a distance of more than 60m from the pumped