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

29 Both 2000 and 2001 were exceptionally wet years (Figure 15). In 2000, the transition between high-flow to low flow conditions came late (May-June), which greatly impeded our access to the river. Peak flow at 5092 cumecs was not particularly high, and well below the record of 8100 of January 1998, but well above the 95th percentile for flow in any of the wet season months of January to March. Average monthly flows in the dry-season exceeded the corresponding median monthly average flows in all months, and Low Flow (< 10 cumecs) occurred only in September and October. The minimum low flow occurred in October at 8.6 cumecs, which exceeded the 90th percentile for recorded September-October flow (Table A2). The dry-season finished typically, with the low-high flow transition occurring in November. Figure 15. Mean monthly flow at Dorisvale gauging station (G8140067) in the two years of the present study. The mean monthly flow (blue line) is compared to the maximum, median and minimum mean monthly flow calculated across the historical dataset. Data for January, March and October of 2000, and in January, March, October and November of 2001 should be viewed with caution, owing to equipment failure. In 2001, the transition between high-flow to low flow conditions was more typical, occurring in April. Peak flow at 2995 cumecs was not particularly high, and also well below the record of 8099 of January 1998, but above the 90th percentile for flow in any of the wet season months of January to March. Average monthly flows in the dry-season equalled the maximum monthly average flow in June through September, and Low Flow (< 10 cumecs) was not achieved in any month. The minimum low flow occurred in October at 10.36 cumecs, which exceeded the 95th percentile for recorded September-October flow (Table A2). The dry-season finished typically, with the low-high flow transition occurring in November. The data for 2000 was consistent with the relationship between rate of decline in flow as the dry season progressed and initial flow conditions (as at June 1) (Figure 16), despite the exceptionally high dry season flows. This is an important relationship, as it is one that is likely to change under any regime of dry-season water extraction, whether directly or by groundwater extraction. It may be an important tool for monitoring the impact of water resource development. 2000 2001