Overview

Toorale station was originally a mixed grazing and irrigation property lying on the Warrego River near the confluence with the Darling Baaka River. The property was purchased by the NSW government, including its water rights in order to promote environmental values. It is now divided into Toorale National Park and Toorale State Conservation Area.

The NSW Government manages water within the park, aiming to balance a range of competing priorities, including the flow of water downstream to the Darling Baaka River and also ensuring the high value ecological assets within Toorale are maintained.

Objectives

Develop the tools required to understand the water balance within the park
Test a range of operational scenarios for water infrastructure to determine the optimal approach to water management

Challenges

One of the key challenges of water modelling in Western NSW, including Toorale, is the very flat topography which leads to slow moving floods that can last months. Evapotranspiration and infiltration can be a high proportion of the water balance and the change of wetland plants density during events can impact key calibration parameters.

Approach

Develop a calibrated hydraulic model to understand how water moves across the landscape at an event time scale
Use key data from the hydraulic model to inform the development of a Source hydrologic model to understand the flow of water over a long period of time under different management scenarios

Solutions

Catchment Simulation Solutions model set is robust, calibrated and peer reviewed
Flow through the park and downstream is now better understood and the hydrological outcomes from various inflows can be predicted
Park and water managers now have a robust tool to assess different management options to best utilise water resources

Toorale Water Balance Modelling