Page 175 - VEWH Seasonal Watering Plan 2020-21
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Scenario planning
Table 4.4.2 outlines the potential environmental watering and expected water use under a range of planning scenarios.
The potential watering actions in 2020–21 have been determined by considering the environmental values, watering requirements and recent watering histories of the Wimmera-Mallee wetlands, as well as available water supply and ability to deliver water to individual sites. The list of wetlands to be watered under each scenario was determined according to the following principles.
Under drought conditions, the highest priority is to provide permanent water in the deeper sections of the wetlands,
to provide drought refuge for waterbirds, frogs, turtles and terrestrial animals across the landscape and to support
the growth and lifecycles of wetland plants. Under wetter scenarios, water for the environment may be delivered, depending on capacity in the pipeline system, to water larger areas of the wetland. Large rainfall events and catchment inflows may partially or fully fill some wetlands, and water for the environment may be used to top up, fill or over-top wetlands to improve fringing wetland plant growth and provide additional habitat for waterbirds, frogs and turtles.
Allocations to the environmental entitlement to supply the wetlands in the Wimmera-Mallee wetland system is highly variable, and the ability to carry over unused water from one year to another allows waterway managers and the VEWH to effectively manage the systems in dry periods. The
North Central, Mallee and Wimmera CMAs and the VEWH have determined that between 122 and 130 ML should be carried over at the end of 2020–21, to support critical environmental demands in 2021–22.
4.4 Wimmera-Mallee wetlands
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