A water quality and quantity model, Source Catchments is designed to help natural resource managers and consultants develop targets, prioritise improvement programs and measure the effectiveness of a broad range of catchment management activities.

The landmark software provides a framework for modelling the amounts of water and contaminants flowing though a catchment and into major rivers, wetlands, lakes, or estuaries. Source Catchments integrates an array of models, data, and knowledge that can be used to simulate how climate and catchment variables (like rainfall, evaporation, land use, vegetation) affect runoff, sediment and contaminants.

eWater CRC CEO Professor Gary Jones said that Source Catchments demonstrates the extensive capabilities, flexibility and integration that will be a hallmark of eWater Source.

“We are very pleased to be putting in the hands of the water industry a capability to tackle complex issues in catchment management and find solutions,” says eWater CRC CEO Professor Gary Jones.

“Source Catchments is a resource that can support the work of natural resource agencies throughout Australia by providing answers based on a track record of scientific research. We have had great feedback from our trial users who are already getting benefits in several states.

“The fruit of collaboration between leading scientists and industry partners, Source Catchments is the first module of the ground breaking eWater Source product that will enhance the management of water in Australia over the next decade.

“A fully functional 12-month free trial of Source Catchments is available for download from the eWater website.”

Fully Integrated

Source Catchments is the first configuration of eWater Source to be released. Previously known as WaterCAST, Source Catchments is built on the E2 modelling to provide additional functionality for assessing the effects of:

• Quantity and quality of rainfall-driven runoff reaching streams in the catchment under present conditions
• Alterations made to quantity and quality of runoff by climate variability, different land uses, or riverbank restoration – now, or in the future 
• Optimal locations for on-ground work to maximise water quality improvement
• Impacts of bush fire, flood, drought, construction activity or water extractions on the quality of receiving waters
• The effect of land use change on water quality and quantity into receiving waters.

Source Catchments can predict the flow and constituent loads at any location in any catchment over time. It usually runs on daily time steps and produces reports at chosen spatial and temporal scales. Scenarios of interest can include actual or planned changes in land use, land management, or climate.

Source Catchments allows users to answer a range of management questions, such as where to place on-ground works to maximise water quality. It can also look at how climate change might affect the sediment balance in the catchment, or what might happen if plantation forestry replaces cropping in a certain sub-catchment. Source Catchments modelling can be set up to handle bush fires, floods, droughts, and construction, all of which can adversely affect catchments.

For the last few years eWater and its partner organisations have been road-testing and refining the software in a number of major catchments around Australia. These catchments include four whose rivers feed into the sea adjoining the Great Barrier Reef (the Fitzroy, Pioneer, Burdekin and Barron).  They also include catchments in Queensland, some catchments of the Hawkesbury–Nepean, the Yarra, and Goulburn–Ovens rivers, and streams in the ACT and the Mt Lofty Ranges, South Australia.