Sunshower Lagoon on the mid Murrumbidgee River.
This year, the highly-variable Murray-Darling Basin has lived up to its reputation as ‘a land of droughts and flooding rains’. While it is great to see rivers flowing once again, we recognise that not all catchments have had rain, and some areas of the Basin still remain drought-declared.
Each year, we plan for very dry through to very wet conditions and adapt to whatever season eventuates. Even in wetter conditions, water for the environment still has an important role to play in the year ahead. Before river regulation, water would flow over riverbanks and cross floodplains to soak natural wetlands regularly. Today, dams, roads and other structures can stop water from reaching many wetlands.
Providing a helping hand
Dry conditions over the past few years mean many of the Basin’s floodplain wetlands are in need of a drink. Natural flows are already providing water to some of these sites now, but water for the environment may be required later in the year to capitalise on nature’s work. When conditions begin to dry out, water for the environment can be used to extend the duration of flows into wetlands, top them up later in the year, or direct water to sites that miss out. This will support the recovery and improvement in wetland plants and the habitat they provide for native wildlife.
Breeding birds
Water naturally filling wetlands may encourage bird breeding events. But if wetlands dry out too quickly, waterbirds will be unable to successfully complete their breeding cycle. To delay the time it takes for wetlands to dry out, water for the environment is used to ‘top-up’ the wetland to maintain breeding conditions and finish what nature has begun.
Reducing risk
Wetter conditions present both opportunities and risks. Because flood conditions pose potential risks to people, farms and animals, we work closely with the community to ensure water for the environment is not delivered where it will exacerbate the impacts of flood-affected land. Wet conditions can also increase the risk of low-oxygen (or hypoxic) blackwater events occurring in the hotter months. Hypoxic blackwater can lead to devastating fish deaths, so we are prepared to deliver water where we can to provide refuge for native fish.
To find out more, see the 2021-22 Water Management Plan and keep an eye on the Commonwealth Environmental Water Holder’s Facebook page for regular updates on using water for the environment.
Many of the Murray-Darling Basin’s catchments are experiencing increased river flows after recent rainfall.