ILWS - Charles Sturt University
ILWS - Charles Sturt University

Study on the use of irrigation infrastructure to create refuge during hypoxic events (2016)

Strategic Research Area

Sustainable Water

Funding

Commonwealth Environmental Water Office (CEWO), $42,000 (Contract variation for the LTIM project)

Researchers/Investigators

Professor Robyn Watts, Dr Julia Howitt, Dr Nicole McCasker, Ms Xiaoying Liu

Description

High rainfalls in winter/spring in 2016 for most of the Murray-Darling Basin led to widespread flooding throughout much of the catchment. Consequently there were hypoxic blackwater events in the Edward-Wakool system with associated fish kills.

In late October, the Commonwealth Environmental Water Holder, David Papps announced that good quality environmental water would be re-directed through the Murray irrigation infrastructure as the flooding receded. The intention was to create local refuges for fish and other aquatic fauna in the Edward and Wakool Rivers. The decision was informed by previous research undertaken by ILWS researchers who assessed the effectiveness of using irrigation canal escapes to deliver environmental water during a hypoxic blackwater event following a smaller flood in 2010, and preliminary modelling done by Dr Julia Howitt, Professor Robyn Watts and Luke Pearce (NSW DPI) to predict the outcomes of using irrigation water to improve oxygen levels in the river.

Members of the Institute's Edward-Wakool research team were commissioned by CEWO late October to study the responses to its environmental watering out of the irrigation canal escapes additional to the monitoring they are already doing for current long-term environmental flows project.

In an experimental design that would enable the researchers to assess the outcomes of the environmental watering, sites were monitored upstream and downstream of four of the escapes and in the Mulwala irrigation canal system through which the environmental water was delivered. 

Outputs 

Regular updates to the CEWO, the Murray Dissolved Oxygen Group (a multi-agency committee) and the Edward-Wakool Environmental water reference group and other stakeholders. Results of the project will be included in the 2017 Edward-Wakool Long-Term Intervention monitoring report. 

Outcomes

The research contributed to adaptive management at two time scales:

  • Immediate feedback to CEWO could adjust its use of environmental water during the watering actions
  • Contribution to longer term planning and inform management decisions in future years

CONTACT

Professor Robyn Watts email

Dr Julia Howitt email

April 2017