University of Canberra
Research Projects
Predicting water quality and ecological responses to a changing climate: a pilot study
State/Territory: NSW

The potential impact of climate changes on water supply volumes has received much attention both locally and internationally, yet relatively little is known about the concomitant changes in water quality and ecological outcomes. This represents a significant knowledge gap for water resource managers and impedes long term planning and strategy development. Central to our lack of understanding is the lack of an integrated set of quantitative tools for predicting the relationship between climate change, extreme events and water quality.

This project is developing a Bayesian Network based modelling framework combining hydrologic, water quality models and ecological models. The framework will enable us to determine how ecosystems respond to changes in water quality and flow. This pilot study is designed to be the precursor of a broader project that will evaluate how changes in climate, most notably how likely increases in extreme event frequency and severity will affect water quality, aquatic ecosystems and management responses.

This study focuses on the Murrumbidgee River and two of its tributaries: the Molonglo and Yass Rivers. The Molonglo River is the exit point for water from the ACT following its treatment at the Lower Molonglo Water Quality Control Centre (LMWQCC). Recent extended periods of low flows and changing water use practices within the ACT have resulted in an increase in the concentrations of Total Dissolved Salts (TDS) in the Molonglo River downstream of the LMWQCC leading to concerns regarding future compliance with Water Quality regulations and subsequent implications for downstream ecological health.

The Yass River is the next major downstream tributary of the Murrumbidgee River from the Molonglo River. Salinity is a major issue within the Yass Catchment, and salinity concentrations within the Yass River are often elevated. The Yass River provides an important point of comparison for the lower sections of the Molonglo River, allowing an assessment of the ecological responses that might be expected as a consequence of elevated TDS levels. It also provides important contextual information regarding the response of the downstream sections of the Murrumbidgee River to high salt inputs. 

Geographic location:
Molonglo and Yass Rivers, ACT & NSW
Research theme:
Climate Change and Sustainability
Institute for Applied Ecology, University of Canberra
iCAM, Australian National University, ACT Government, ACTEW
Funding agency:
University of Canberra
Main researchers:
Dr Fiona Dyer, Dr Evan Harrison and Prof Richard Norris, University of Canberra
01 Jul 2010 - 30 Jun 2011