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

50 Dorisvale and Jinduckin Creek. Temperatures at the input end of the section (Dorisvale) were those measured at this site. Figure 29. Location map for the river temperature measurement sites and the spring. The Daly River flows approximately towards the northwest. At the spring, warm water is discharged into the river causing a change in the river water temperature. Suppose Tupstream is the modelled temperature in the river upstream from the spring and Tdownstream is the river temperature immediately downstream from the spring, then: T T Q T Q Q Qdownstream upstream u spring spring u spring = + + (2) where Quis the flow in the river upstream from the spring. We calculate the downstream flow speed as: U Q Q WD u spring= + (3) where W is the river width. Tupstream , as calculated from Eq. 2, was specified as the river temperature just downstream from the spring. The model solution between the spring and Jinduckin Creek and Cattle Creek was integrated with time and distance in the same way as it was for the river section between Dorisvale and the spring. As in the upstream section, the initial water temperatures specified for the model in the river section downstream from the spring were obtained as linear interpolations of measured temperatures. The model requires the specification of W and D as a function of river discharge. For model application we divided the river up into three sections each with uniform W and D. These sections were Dorisvale to the spring, the spring to Jinduckin Creek, and Jinduckin Creek to Cattle Creek. The relationships between discharge, W, and D in each section were determined by applying the hydrology model developed in HECRAS to measured river cross sections and discharges. The river between Dorisvale and Cattle Creek consists of a series of pools connected by riffle zones and the hydrology model was capable of resolving these. The