Territory Stories

East Alligator district centre water supply assessment : Kakadu National Park

Details:

Title

East Alligator district centre water supply assessment : Kakadu National Park

Other title

D . Pidsley

Creator

Jamieson, M.; Pidsley, D.; Paiva, Jerome

Collection

E-Publications; E-Books; PublicationNT; Technical Report ; 26/1991

Date

1991-02-26

Description

Made available via the Publications (Legal Deposit) Act 2004 (NT).

Notes

Date:1991

Language

English

Subject

Water-supply -- Northern Territory -- Kakadu National Park; Groundwater -- Northern Territory -- Kakadu National Park; Kakadu National Park (N.T.)

Publisher name

Power and Water Authority

Place of publication

Darwin

Series

Technical Report ; 26/1991

Format

1 v. : ill., maps ; 30 cm.

File type

application/pdf.

Copyright owner

Check within Publication or with content Publisher.

Parent handle

https://hdl.handle.net/10070/229020

Citation address

https://hdl.handle.net/10070/673451

Page content

Technical Report WRD91026 Viewed at 15:07:48 on 29/07/2010 Page 79 of 107. APPENDIX 4 DRILLING AND PUMp TESTING In 1976 two bores (RN's 8918 and 8919) were drilled at a day use area adjacent the East Alligator River (see Diagram 4 for bore locations). These bores were drilled to about 14 m depth into sil ts and sandstone. The respective airlift yield from these bores when drilled was 0.75 L/s and 0.4 L/s. The first bore to produce water for the ranger station was RN 20480 which was drilled in 1979 to a depth of 60 m. No record of the strata encountered in this hole exists, but when drilled an airlift produced 0.4 L/s for one hour. In October 1980 a resistivity survey was conducted in this area. See Diagram 4 for the location of the traverse, and Diagram 6 for the results of this survey. Based on this geophysical data, si tes for the following bores were chosen, RN' s 20559, 20636, 20637, 23449 and 23450. These bores were drilled in zones of low resistivity, which proved to be due to weathered and fractured Kombolgie sandstone. Fracturing occurs at depths of 14-26 m. This fracturing has been caused by the faulting in the Bulman Fault Zone (see Diagram 4). RN 20559 and 20561 were located on the most easterly area of low resistivity (station position 1200 m) found from the geophysics survey. Clayey sand was encountered to 10 m, followed by brown Kombolgie sandstone to 116.2 m. An airlift of 0.3 L/s (while drilling) from 20561 and 2 L/s from 20559 (after construction) werE> achieved from depths of around 90 m. RN 20559 was recommended a maximum continuous pumping rate of 1.5 Lis based on pump testing (see Table A4. 1 for pump test information) . Five bores have been drilled within the western area of low resistivity (at station position of around 2000 m, see Diagram 6). RN 20560 was drilled to 104 m depth and encountered different strata (due to faulting) than 20559 or 20561. Clayey sand was found to 11 m depth, brown clay and sandstone to 24 m, brown and green siltstone to 101 m, clay and sandstone to 104 m 005MJ