Territory Stories

Modelling dry season flows and predicting the impact of water extraction of flagship species

Details:

Title

Modelling dry season flows and predicting the impact of water extraction of flagship species

Creator

Georges, Aurthur; Webster, Ian; Guarino, Fiorenzo; Jolly, Peter; Thoms, Martin; Doody, Sean; CRC for Freshwater Ecology (Australia); University of Canberra. Applied Ecology Research Group

Collection

E-Publications; E-Books; PublicationNT; 57/2002; National River health program

Date

2002-11-20

Location

Daly River

Abstract

The aim of this project is to contribute to recommendations on environmental flows to ensure that they are consistent with maintaining the biota of the Daly River, given competing demands of agriculture, recreation and tourism, conservation and Aboriginal culture. Our focus is on flow, connectivity and water temperatures.

Notes

Made available by via Publications (Legal Deposit) Act 2004 (NT); Submitted to the Northern Territory. Department of Infrastructure Planning and Environment

Table of contents

1. Project Details -- 2. Executive Summary -- 3. Interpretation of the Brief -- 4. Variation of the Brief -- 5. Background -- 6. The Daly Drainage -- 7. The Pig-nosed turtle -- 8. Analysis of Historical Flow Data -- 9. Analysis of Contemporary Flow Data -- 10. Modelling Flow Reduction -- 11. Water Temperature Versus Flow -- 12. Impact on Flagship Species -- 13. References

Language

English

Subject

Environmental Flows; Modelling; Biota

Publisher name

Northern Territory Government

Place of publication

Palmerston

Edition

Final Report

Series

57/2002; National River health program

Format

75 pages ; 30 cm

File type

application/pdf

Use

Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government

License

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

Parent handle

https://hdl.handle.net/10070/885434

Citation address

https://hdl.handle.net/10070/885435

Page content

48 Stratification To test for the possibility that the Daly River may stratify if flows were reduced, we established two depth profiles in Ruby Billabong (Figure 27), a billabong formed in a former channel of the Daly River, with zero flow but water characteristics otherwise similar to that in the river itself. The billabong was full to bank height, and so was of greater depth than water in the river. The profiles showed that stratification did not occur until a depth of 5.0 m (Figure 28), and even at that depth, a surface influence was evident depending upon wind strength. As the maximum dry season pool depth observed in the river was 4.28 m (flow 27.4 cumecs). It was therefore considered reasonable to eliminate the possibility of stratification from our temperature calculations for even zero flow scenarios. Northing 8000 8200 8400 8600 8800 9000 9200 Ea st in g 65600 65650 65700 65750 65800 65850 -2 -4 -6 -2 -2 -4 -6 -8 Figure 27. Contour map for Ruby Billabong showing the two locations () where the thermal profiles were measured. Temperatures were recorded at 10 cm, 50 cm, 1 m, 2 m, 3 m, 5 m, 7 m.