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 MurrayDarling Basin (MDB) Plan aims to protect and restore water dependent ecosystems. It includes the voluntary purchase of water entitlements from irrigators, with this water allocated to the environment. However, in parts of the MDB the delivery of environmental water is constrained by established river operating rules and practices that control the timing, duration or magnitude of

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 and spring and lower in summer and 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 implemented in 2017 and 2018, following extensive consultation with landholders and agency representatives, involved changes to operating rules and practices. 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 was undertaken to examine hydrological connectivity, extent of inundation, water quality and river productivity. Social research explored how landholders and water managers perceived the flow
trials. The extent to which these trials could contribute to informed decision making and adaptive management of environmental water in this system was also examined.

The flow trials increased hydrological connectivity and production of carbon within the river and there were no negative water quality outcomes recorded. The social survey found a general desire for action over extended planning, and acceptance of experimenting with environmental water to ensure eventual best outcomes. There was a positive response to the winter flow trial and community observations of improvements in water quality. While the higher 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. Indeed, the community responses to the flow trials were often framed systemically, and discussed in relation to the bigger, more complex picture
of water management in the southern MDB system.

Large river restoration programs usually refer to the need for adaptive management but there are typically few examples that examine outcomes of changes to normal river operating rules and practices. There is potential for environmental flows to improve environmental, social and economic outcomes. Undertaking experiments, sharing the learnings and including a wide range of
perspectives remain the keys to achieving ongoing outcomes from delivering environmental flows.
Original languageEnglish
Number of pages1
Publication statusPublished - 2019
Event6th Biennial Symposium of the International Society for River Science (ISRS) 2019 - Vienna, Austria
Duration: 08 Sept 201913 Sept 2019


Conference6th Biennial Symposium of the International Society for River Science (ISRS) 2019
Abbreviated titleOne earth, many rivers, one global society
OtherThe 6th Biennial Symposium of the International Society for River Science (ISRS) was hosted by the Institute of Hydrobiology and Aquatic Ecosystem Management at the University of Natural Resources and Life Sciences Vienna (BOKU) in Vienna, Austria, 8-13 September 2019. The conference theme was “Riverine landscapes as coupled socio-ecological systems“.

The symposium emphasised research on the use and protection of water resources with a focus on highly modified riverine landscapes. It linked research at different trophic, temporal and spatial scales and bridges between ecology, geomorphology, hydrology, biogeochemistry, social sciences, environmental engineering, technology and economics. The symposium therefore served as a wide platform for the exchange of ideas and experiences between science and practice.
Internet address


Dive into the research topics of 'Environmental flow trials in a regulated river in southern Australia: Integrating biophysical and social research'. Together they form a unique fingerprint.

Cite this