Page 10 - VEWH Seasonal Watering Plan 2020-21
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 1.1 The Victorian environmental watering program
Figure 1.1.1 A typical Victorian river catchment before and after the development of dams, weirs and channels.
1.1.2 What do we mean by ‘water for the environment’?
Water for the environment is water that is overseen by environmental water holders and released at a time and rate intended to improve the health of river and wetland systems including their biodiversity, ecological function, water quality and other uses that depend on environmental condition. It’s not the only water that contributes to environmental condition, but it is water that governments reserve specifically to be actively managed to help mitigate the environmental impacts resulting from the modification of rivers and wetlands to supply water for consumptive uses. ‘Environmental flows’ and ‘environmental water’ are other terms to describe water for the environment.
The amount of water for the environment available to be released each year is described in environmental water entitlements, which are legal rights to water that is available in a reservoir or river system or another specified location. Environmental water entitlements have rules and conditions similar to those in other water entitlements used to reserve water for towns, irrigators and industry.
Environmental water holders must make decisions about the best use of this water each year, and the seasonal watering plan is the public preview of the types of decisions that might be made about environmental water entitlements in Victoria under a range of different circumstances throughout the year.
For more information about water for the environment, including how other water sources are considered in the planning and management of this water, see section 1.4.
1.1.3 What do we aim to achieve with water for the environment?
Water for the environment aims to support the habitat, feeding and breeding needs of native aquatic plants and animals. This includes maintaining flows or permanent pools in rivers that would otherwise dry out; maintaining water quality within tolerable limits; providing triggers for fish to migrate; watering wetlands to support carbon and nutrient cycles and to stimulate the growth of plankton, waterbugs or small fish to provide food for larger fish and waterbirds; and watering vegetation to keep it alive or to trigger new growth. To do these things, water for the environment is released into rivers to mimic some of the flows that would have occurred naturally, before the construction of dams, weirs and channels. This helps maintain the physical, chemical and biological health of rivers.
Environmental water managers set the timing, duration
and volume of water releases to return some of the small- and medium-sized river flows that are essential in the life cycles of native plants and animals. For example, Australian grayling are signalled by an increased river flow in autumn to migrate downstream for spawning: to release their eggs. Breeding waterbirds need wetlands to retain water for long enough for their chicks to grow and fledge, and floodplain forests need to be inundated every few years to ensure
the iconic tree species (such as river red gums and black box) survive and reproduce. Water for the environment
also moves sediment and nutrients through river systems, connect habitats and improves water quality.
8 | Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21

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