Territory Stories

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



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


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


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




Daly River


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.


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




Environmental Flows; Modelling; Biota

Publisher name

Northern Territory Government

Place of publication



Final Report


57/2002; National River health program


75 pages ; 30 cm

File type



Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government



Parent handle


Citation address


Page content

38 The largest pool under Extreme Low flow conditions (6.1 km) extends from behind Old Oolloo crossing to Neils Rapids (ca 1 km below Jinduckin Creek). The next largest pool (5.1 km) extends from behind control point 9. These two pools are separated by 13.8 km of river and are likely to be the main refuges for riverine biota under extreme low flow conditions. The smallest substantial pool (622 m) extends from control point 7 to control point 5. The overall mean maximum channel depth, flow cross-sectional area, top width and wetted cross-sectional perimeter for the study site was 1.5 m, 64 m2, 55 m, and 55 m respectively. Corresponding morphology for each of the two-pool size classes are presented in Table 7. Apart from length, their profiles were very similar, a reflection of the relatively common morphology of the Daly River across the study site. Table 7. Morphological parameters for pools among 2 size classes. Means are given with standard deviations. Size Class Length (m) Flow area (m2) Top width (m) Wetted perimeter (m) Maximum depth (m) Small 1507 632 (622-2617) 64.8 21.3 (17.8-106.0) 55.3 4.5 (42.8-62.7) 55.7 4.6 (42.9-63) 1.5 0.4 (0.7-2.2) N=26 N=26 N=26 N=26 N=26 Intermediate 4404985 (3020-6104) 63.119.3 (34.3-86.8) 55.23.5 (50.4-59.8) 55.63.5 (50.7-60.3) 1.50.3 (1.0-1.9) N=7 N=7 N=7 N=7 N=7 There were no significant differences (as demonstrated by ANOVA) in flow area, top width, wetted perimeter, and maximum depth between the two size classes. Pool length was the only factor that separated the pools into class. Furthermore, there was no correlation between pool length and any other morphological parameter. Pools shared similar morphological parameters independent of length.