Page 127 - VEWH Seasonal Watering Plan 2020-21
P. 127

Environmental watering objectives in the upper Barwon River
Social, recreational and economic values and uses
In planning the potential watering actions in Table 3.7.1, Corangamite CMA considered how environmental flows could support values and uses including:
• water-based recreation (such as canoeing, fishing, kayaking and swimming)
• riverside recreation and amenity (such as bird watching, walking, camping, picnicking and using parks and lookouts)
• socio-economic benefits (such as diverters for irrigation, domestic and stock uses).
Recent conditions
Total rainfall in the Barwon River catchment was slightly below average during 2019–20 but varied within and between seasons. Significant rain in July and August 2019 filled the West Barwon Reservoir from 26 percent capacity to 60 percent capacity, and rainfall between January and May 2020 was above the long-term average.
Natural inflows maintained an average flow of 50 to70 ML per day at Winchelsea throughout winter and spring 2019 and delivered several high-flow events and freshes including a peak flow of 3,560 ML per day at Winchelsea in mid-July 2019. Water for the environment was used to maintain minimum low-flow targets (up to five ML per day) in the
east branch of the upper Barwon River during summer, to maintain water quality and instream habitat for native fish and platypus and to maintain aquatic vegetation. Small freshes up to 15 ML per day were delivered in January and March 2020 to allow fish and other aquatic animals to disperse and maintain vegetation higher up the banks. The recommended fresh of 35 ML per day cannot currently be delivered due to channel constraints.
Scope of environmental watering
Table 3.7.1 describes the potential environmental watering actions in 2020–21, their functional watering objectives (that is, the intended physical or biological effect of the watering action) and the longer-term environmental objective(s) they support. Each environmental objective relies on one or more potential environmental watering actions and their associated physical or biological functions.
3.7 Barwon system
    Maintain the abundance, and improve the breeding and recruitment of migratory fish species including short-finned eels, Australian grayling and tupong, broad-finned galaxias and common galaxias
Maintain the abundance, and improve the breeding and recruitment of resident freshwater fish including several species of galaxias, Australian smelt, big-headed gudgeon, Yarra and southern pygmy perch and river blackfish
     Maintain the abundance and improve the condition and extent of platypus populations
   Improve the condition and extent of instream vegetation, to provide structural habitat for waterbugs and various fish species
Improve the condition, extent and diversity of emergent macrophyte vegetation and streamside vegetation to provide structural habitat and stabilise the channel and lower banks
    Increase the abundance and improve the breeding and recruitment of waterbugs as a food source for fish, frog and platypus populations
    Maintain water quality for native fish, waterbugs, aquatic vegetation and other water-dependent animals
Traditional Owner cultural values and uses
The Corangamite CMA is working with Eastern Maar
and Wadawurrung Traditional Owners to understand opportunities to provide for both groups’ respective cultural values and uses and other aspirations for environmental water management throughout the Barwon system.
The reaches of the Barwon River that can be most influenced by water delivered from the West Barwon Reservoir sit in Eastern Maar Country. Good opportunities exist within these reaches for actively managed shared benefits in the future.
Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21 | 125

   125   126   127   128   129