Water for the environment is water released into rivers to help plants and animals who need a helping hand at particular times of their lifecycle.
Corangamite CMA is responsible for operating the Environmental Water Reserve (EWR) in the Corangamite region on behalf of the Victorian Environmental Water Holder. We work closely with regional water authorities, Traditional Owners, local government and community to have a positive influence on regulated river systems within our catchment.
Why does the environment need water?
Healthy rivers and wetlands are living ecosystems that provide a range of services we all benefit from, including nutrient cycling, water filtration, climate moderation and flood mitigation. Healthy rivers and wetlands are also a home for birds, platypus, frogs and fish, and places for people to enjoy fishing, picnicking, walking, swimming and boating.
Since European arrival many river systems have been significantly modified to provide water for urban and agricultural use. Corangamite CMA manages three Environmental Entitlements in the Corangamite region, in the Moorabool River, upper Barwon River and lower Barwon wetlands. On these systems, releases of water from reservoirs and barriers are carefully timed with the aim of improving downstream waterway health. As our climate changes, water for the environment is more important than ever.
How do we know what a river or wetland needs?
Science underpins all our decision making. Corangamite CMA commissions technical FLOWS studies for the rivers and wetlands within our region where water can be managed for environmental outcomes.
FLOWS studies look at the hydrology and hydraulics of the system, and the environmental and cultural values, and provide recommendations for efficient management of water to benefit these values. These recommendations might include pulses of water in spring to trigger fish migration and spawning, or continuous low flows over the dry summer period to maintain water quality and connection between habitat pools.
FLOWS Studies are updated every 5-10 years to reflect current conditions and the best available information.
How do we know it is working?
FLOWS studies inform the recommendations for delivery of water for the environment in a river or wetland, taking into consideration the waterway’s ecology, structure, cultural values and surrounding hydrology.
The Victorian Government monitors representative rivers and wetlands across the state through the Victorian Environmental Flows Monitoring and Assessment Program (VEFMAP) for rivers and the Wetland Monitoring and Assessment Program for environmental watering (WetMAP).
VEFMAP and WetMAP programs are coordinated by the Arthur Rylah Institute and include long-term condition monitoring, event-based monitoring of environmental flows, collaborative research projects with universities, retrospective analysis of data and modelling.
Corangamite CMA also funds monitoring including fish surveys on the Moorabool River, water quality testing at Reedy Lake and e-DNA surveys for platypus on the upper Barwon. A Corangamite CMA pilot project is currently investigating whether regional Waterwatch datasets can demonstrate the benefits of water for the environment.
Delivery of water for the environment provides shared benefits to all types of river uses, particularly when water is added to a system. Wherever possible, delivery of water for the environment is adapted to maximise benefits to river and wetland users. This is usually achieved by adjusting the timing of a water release or drying action to accommodate recreational activities or events, such as hunting or boating.
An example of this is the environmental watering regime implemented at Reedy Lake in the Lower Barwon Wetlands. Like many wetlands in Australia, Reedy Lake is meant to have periods of low water and periods of flooding. This variation is important in maintaining a diversity of habitats at the wetland, and the ecological character of this Ramsar listed site. Reedy Lake is also part of the Lake Connewarre Game Reserve. To accommodate the opening of duck season, the Corangamite CMA aim to have a certain minimum level of water in the lake prior to season opening. This timing adaptation can be done when there is sufficient flow in the Barwon River to allow early filling.
Traditional Owner partnerships
Corangamite CMA partners with Traditional Owners wherever possible to manage the environmental water reserve in our region.
The Wathaurung Aboriginal Corporation (the Wadawurrung) were members of the technical panel for the 2019 Upper Barwon – Yarrowee Leigh FLOWS study. The Wadawurrung provided expert input to identify cultural values on the river reaches that flow through Wadawurrung country. These values include culturally significant species, habitat features and meeting places, which can now be taken into account through the delivery of environmental water.