How science informs the use of water for the environment

Written by Irene from the Commonwealth Environmental Water Holder.

Once again we are kicking off a particularly busy period in the Commonwealth Environmental Water Holder (CEWH) as we start planning for the new water year (which occurs from 1 July to 30 June). This annual process runs from February to June and sees us work with stakeholders across the vast Murray–Darling Basin to develop plans on how to use water for the environment.

In this article, we’ll take a closer look at how, why and when science is used as a critical input into planning and delivery of water for the environment. But before we answer that, it’s important to understand what water for the environment is.

What is water for the environment?

Water allocated to keep the rivers, wetlands and floodplains healthy is known as water for the environment. This water is carefully managed to ensure it delivers the best environmental outcomes. An environmental flow can be water that is:

  • released from a dam or weir to maintain downstream river health
  • delivered to a wetland or floodplain using pumps or other infrastructure
  • left in a river and protected from being extracted.

The Commonwealth Environmental Water Holder (CEWH) is responsible for managing on average almost 2,100 gigalitres* of water (more than 4 Sydney Harbours) for the environment each year and does this with the help of the CEWH.

*The amount of water available through entitlements varies each year, depending on how much is allocated by state governments. In times of drought, allocations to entitlements are reduced the same way for all water users— including environmental water holders. Water entitlements managed by the CEWH are subject to the same allocations, fees, rules and carryover arrangements as all other users.

The importance of science in planning

Science is an important knowledge base that helps us understand our world and achieve our national social, economic and environmental objectives. Science enables us to question, explore, and identify things we don’t understand. The CEWH’s investment into the Flow – Monitoring, Evaluation and Research (Flow-MER) Program is providing us with more knowledge and understanding about the plants and animals of the Murray–Darling Basin. This will help ensure that we can make decisions about how best to use every single precious drop of water for the environment – when our researchers and local practitioners tell us that the time is right.

Commonwealth Environmental Water Holder Hilton Taylor and Local Engagement Officer Jason Wilson on Country.
Credit: Commonwealth Environmental Water Holder.

Scientific knowledge has undergone a process of validation such as peer review

The reason we use science is simple. Science follows a systematic and logical process that helps us understand how things work. The knowledge generated undergoes a process of validation such as peer review where, based on data, repeated tests, critical evaluation and debate, qualified experts have reached consensus on an issue. As such, findings generated through this process provide a sound and community accepted foundation on which decisions can be based and importantly, these results can be respectfully and methodically challenged. This is why the CEWH uses science to inform the management of the Commonwealth’s environmental water holdings.

Science is just one knowledge input into the planning process

The experience and knowledge of scientists is just one of the many pieces of information we consider in the use of water for the environment. Our decisions about when, where, why and how much water to use also involves input from First Nations, local communities, landholders, interest groups, river operators and multiple State and Federal government agencies. By including a range of perspectives, experiences, and knowledge in the planning process, we’re able to make decisions about how to manage water for the environment to improve the health of the Murray–Darling Basin.

Staff of the CEWH attend a range of community meetings across the Basin which allows them to hear from stakeholders on the ground. Credit: Commonwealth Environmental Water Holder.

Science provides evidence to enable adaptive management

Science has been helping the CEWH plan and deliver water for the environment for over 10 years. While there are many things we now know about the fish, frogs, birds and plants of the Murray–Darling Basin, there are information gaps that remain. The Flow-MER Program continues to help fill-in these gaps and inform the adaptive management of water for the environment. Evaluating the results of monitoring allows us to gain a much better picture of what places, plants and animals need water each year and allows us to understand the responses we see in the environment.

The Flow-MER Program allows us access to some of the best and most up-to-date scientific knowledge to help us manage water for the environment. Many of the scientists working on Flow-MER projects are recognised as leading experts in their fields both here in Australia and overseas. These scientists have years of training and experience in the environments of the Murray–Darling Basin and of the plants and animals that call the rivers, wetlands and floodplains home. With many of the scientists also calling the Murray–Darling Basin home too, they are in a unique position to tell us what they’ve seen and heard from the people in their river communities.

We rely on scientists to tell us when they think we need to change our approach during planning and water delivery, including balancing competing priorities. We’re continually working with scientists to ensure that the evaluation of achievements made with Commonwealth environmental water is:

  • based on robust data and standards
  • underpinned by accepted evaluation techniques
  • made available to anyone who requests it, including the data which sits behind the results.

Associate Professor Qifeng Ye from SARDI undertakes monitoring in the Lower Murray Selected Area.  Credit: South Australian Research and Development Institute.

The CEWH’s planning process

Every year is different—some years are wet, some are dry, some are a mixture of both wet and dry—so we plan for a range of scenarios to enable us to adapt our water use to the seasonal conditions which eventuate.

Countless meetings, forums and conversations will be held over the coming months to develop these plans. To ensure we use the best available scientific information, we’ll be holding a series of workshops with Flow-MER scientists over the coming weeks. These workshops will complement the regular conversations between CEWH staff and scientists from across the Basin and ensure the latest findings can be incorporated into Commonwealth environmental water use for the year ahead. To find out more about the CEWH’s planning process, head to

Un-specked hardyhead. Photo credit: Gunther Schmida.

Learn more about FLOW-MER governance and reporting

Flow-MER brings together the CEWH, CSIRO, Australian River Restoration Centre, State Government Agencies and Universities to provide the science and knowledge to support the adaptive management of the delivery of Commonwealth environmental water in the Murray-Darling Basin.

Learn More


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