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

68 >14.7 Boom River continuous flowing system; home ranges unrestricted; access to nesting banks and feeding beds unrestricted; natural temperature regime. No impact on life history. 6.6 3.7 2.2 1.3 0.9 13.3 (11.9-14.7) Boom River fragmented into 3 pools, one large (19.5 km) and two very large (20 and 35.5 km); only 10% of the river would restrict home ranges; access to nesting unrestricted and 40% of the river has no access to feeding grounds; no appreciable thermal impact. 4.3 2.7 1.4 0.8 0.4 10.5 (9.1-11.9) Boom River fragmented into 6 pools, two large (7.5 and 9.5 km) and two very large (20 and 31.7 km); 30% of the river would restrict home ranges; access to nesting unrestricted and 46% of the river has no access to feeding grounds; no appreciable thermal impact. 8.6 4.1 2.6 1.3 0.7 7.6 (6.2-9.1) Intermediate River fragmented into 11 pools, 4 large (9.4, 10.2, 16.8, 17.8 km) and none very large; 53% of the river would restrict home ranges; access to nesting unrestricted and 51% of the river has no access to feeding grounds; no appreciable thermal impact. 24.9 8.5 4.2 2.6 1.4 4.8 (3.4-6.2) Bust River fragmented into 19 pools, 3 large (9.2, 10.2, 11.1, km) and none very large; 100% of the river would restrict home ranges; substantial probability that a turtle will not be able to nest (up to 35%); and 53% of the river has no access to feeding grounds; no appreciable thermal impact. 40.8 23.5 7.7 3.9 2.5 2.0 (0-3.4) Bust River fragmented into 33 pools, none large or very large; 100% of the river would restrict home ranges of all female turtles; substantial probability that a turtle will not be able to nest (up to 55%); and 53% of the river has no access to feeding grounds; no appreciable thermal impact. 14.8 46.3 28.5 10.1 4.8 Zero Catastrophic River fragmented into 33 pools, or greater if water levels drop below cease-to-flow levels; none large or very large; 100% of the river would restrict home ranges of all female turtles; substantial probability that a turtle will not be able to nest; feeding grounds threatened as they are flow dependent; potentially substantial thermal impact as water depth drops appreciably below ceaseto-flow levels. 0.0 11.3 53.5 79.9 89.3 1 This column indicates the percentage of years between 1960 and 2002 when flows in the flow range shown would have occurred. In terms of population dynamics, a boom period occurs when conditions are such that reproductive output not only ensures that current population levels are sustained, but is also sufficient to fully offset low recruitment that that would have otherwise resulted in population decline in preceding "bust" periods. Boom years may well be infrequent, and it is to be expected that the bust years would numerically dominate the boom years. Changing the