Environmental flow trials in a regulated river in southern Australia: Integrating biophysical and social research

Robyn Watts (Presenter), C Allan, Xiaoying Liu, John Trethewie, Nicole McCasker, Julia Howitt, Nicholas R. Bond, Damian McRae, Katherine Reid, Bruce Campbell, P. Childs, Sascha Healy, Mike Grace, Jason Thiem

Research output: Other contribution to conferenceAbstractpeer-review


Environmental flows are increasingly part of river restoration programs. In Australia, the Murray-Darling Basin (MDB) Plan aims to protect and restore water dependent ecosystems, and includes the voluntary purchase of water entitlements from irrigators, with this water allocated to the environment. However, the delivery of environmental water is often constrained by established river operating rules and practices that control the timing, duration or magnitude of flows.

This study focused on the Wakool River in the southern MDB. Prior to river regulation the average daily discharge in this system was higher in winter/spring and lower in summer/autumn. Under regulated operating rules the infrastructure delivering water to this river is usually closed during winter (ceasing the flow) and there are upper limits on discharge at other times of the year to avoid inundation of low-lying private bridges and land. Two flow trials involving changes to operating rules and practices were implemented following extensive consultation with stakeholders. A continuous base environmental flow was delivered during winter 2017, and in September 2018 an environmental flow pulse was delivered that exceeded the maximum daily discharge under regulated operating rules. Biophysical monitoring examined hydrological connectivity, extent of inundation, water quality and river productivity. Social research explored how landholders and water managers perceived the flow trials and the extent to which these trials could contribute to informed decision making and adaptive management of water.

The flow trials increased hydrological connectivity and production of carbon within the river and there were no negative water quality outcomes. The social survey found there was a general acceptance of experimenting with environmental water to achieve good outcomes. There was a positive response to the winter flow trial with community observations of improvements in water quality. Although the 2018 spring pulse did not interrupt landholder practices or result in poor environmental outcomes, it caused some concern about how river flows might be managed in the future. A number of ways of ‘framing’ conversations about environmental water is emerging, the dominant of these being a ‘systems perspective’ framing. This emerged alongside other strong framings of engineering, water accounting, ecology and power.

Large river restoration programs frequently involve adaptive management but there are few interdisciplinary programs that examine outcomes of changes to established river operating rules and practices. Undertaking experiments, sharing the learnings and including a wide range of perspectives are essential to achieve environmental, social and economic outcomes from environmental flows.
Original languageEnglish
Number of pages1
Publication statusPublished - 2019
EventAustralian Freshwater Sciences Society & New Zealand Freshwater Sciences Society 2019 Joint Conference - Deakin University, Waurn Ponds, Australia
Duration: 01 Dec 201904 Dec 2019


ConferenceAustralian Freshwater Sciences Society & New Zealand Freshwater Sciences Society 2019 Joint Conference
CityWaurn Ponds
Internet address


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